Diagnostic Information
If an intermittent problem is found, follow the instructions below.
Preliminary checks
Before using this section, you must first complete «Diagnostic system check.»
First, conduct a thorough inspection. This inspection often corrects the problem without further checks and saves valuable time. Check the following:
- The ECM ground is clean, properly tightened, and in the correct location.
- Vacuum hoses must be free of cracks, kinks, in good condition and connected according to the emission control label. Check hoses carefully for leaks and blockages.
- Air leakage at the throttle body mounting area and intake manifold sealing surfaces.
- Ignition wires for cracks, hardness, correct routing and leakage current.
- Correct wiring connection.
- Wiring on clips or cuts.
Table of diagnostic trouble codes
Do not use the DTC table (DTC) to troubleshoot intermittent faults. The fault must be present in order to determine its location.
Incorrect application of the DTC table may result in unnecessary replacement of parts.
Faulty wiring or connections
Most intermittent faults are caused by faulty wiring or connections. Thoroughly check suspicious circuits for the following faults:
- Weak contact in connectors.
- The terminals are loosely seated in the connector housing.
- Deformed or damaged terminals. All connector terminals on faulty circuits must be carefully checked, repaired, or replaced to ensure good contact.
- Weak connection of terminals with wires. Removal of the terminal from the connector housing is required.
Sea trial
If a follow-up inspection does not determine the cause of the problem, a road test can be performed with a voltmeter or scan tool connected to the suspect circuit. An abnormal signal level or an abnormal scan tool reading indicates a problem in this circuit.
If there are no abnormalities in the wires or connectors and a DTC is stored for the circuit that has the sensor, the sensor must be replaced.
Engine power system
Some intermittent vehicle handling problems may be due to poor fuel quality. If the car occasionally jerks, stalls, or has other problems, ask the customer how he fuels the car.
- Does he always fill up the car at the same gas station? In this case, fuel problems can be ignored.
- Does he fill up his car at the gas station that offers the lowest prices? If yes, check the fuel tank for deposits, water or other contamination.
Procedure for determining the parameters of idling
The following idle determination procedure must be followed when any one or more of the following actions are performed:
- Replacement with a new ECM
- Replacing a new throttle body (MTIA, ETS)
- Replacement with a new IAC valve
- Cleaning the throttle body
- Disconnecting from the power supply (battery wire, ECM fuse, etc.) (Delphi ECM only)
1. Turn on the ignition.
2. Reset the adaptation values with the scan tool. (Only with drive reg. cold progress of chapters. dross. flaps, coolant sensor engine fluids.)
3. Switch off the ignition for 15 seconds.
4. Switch on the ignition for 5 seconds.
5. Switch off the ignition for 15 seconds. (For the Siemens D160 ECM with ETC, turn off the ignition for 35 seconds.)
6. Start the engine in park/neutral.
7. If the vehicle is equipped with an automatic transmission, apply the parking brake. Pressing the brake pedal, shift the gearbox to position D (movement) for 1 second and return it back to position P (parking). (Siemens ECM only).
8. Let the engine run until the coolant temperature is above 85°C (185°F).
9. Turn on the air conditioner for 10 seconds, if available.
10. If the vehicle is equipped with an automatic transmission, apply the parking brake. Depress the brake pedal, put the gearbox in position D (movement) for 10 seconds.
11. Turn off the air conditioner for 10 seconds, if available.
12. If the vehicle is equipped with an automatic transmission, depress the brake pedal and shift the transmission to park/neutral.
13. Switch off the ignition. The procedure for determining the parameters of idling is completed.
14. Wait 15 seconds before restarting the engine (only for Siemens ECM). (For the Siemens D160 ECM with ETC, turn off the ignition for 35 seconds.)
Diagnostic system check
Circuit Description
The diagnostic system check is the starting point for any diagnosis of driving problems. Check the ECM and engine ground for cleanliness and tightness before performing this procedure.
The diagnostic system check is a well-established technique for identifying problems caused by a malfunction of the electronic engine control system.
Diagnostic Information
An intermittent fault can be caused by a loose connection, frayed insulation, or a broken wire under the insulation. Check for loose contacts or damaged wiring harnesses. Inspect the ECM harness and connections for loose connections, bad locks, bent or damaged terminals, loose terminal-to-wire connections, and damaged harnesses.
Description of the test
The numbers below refer to the operation number in the diagnostic table:
1. The Malfunction Indicator Lamp (MIL) should be permanently lit with the ignition on and the engine stopped. If not, go to Diagnostic Information".
2. This test examines the Class 2 data circuit and the ECM's ability to transmit serial data.
3. This tests the ability of the ECM to drive the MIL and that there is no short to ground on the MIL circuit.
4. If the engine does not start, see paragraph The crankshaft turns, but the engine does not start» in this section.
7. A scan tool setting outside the typical range helps determine the area that is causing the problem.
10. This vehicle is equipped with an ECM using Electrically Erasable Programmable Read Only Memory (EEPROM). The replacement ECM must be programmed. ECM reprogramming is described in the latest Techline.
Diagnostic system check
Step | Operation | Values | Yes | No |
1 |
Is the Malfunction Indicator Lamp on?
|
-
|
Go to operation 2
|
|
2 |
Does the scan tool output ECM engine data?
|
-
|
Go to operation 3
|
Jump to operation 8
|
3 |
Is the Malfunction Indicator Lamp off?
|
-
|
Go to operation 4
|
|
4 |
Try to start the engine.
Does the engine start and continue to run?
|
-
|
Go to operation 5
|
|
5 |
Select DISPLAY DTC with a scan tool.
Are any diagnostic trouble codes saved?
|
-
|
Go to operation 6
|
Jump to Operation 7
|
6 |
Check the appearance of diagnostic trouble codes P0107, P0108, P0113, P0118, P0122, P0123 on the display.
Are two or more of the following DTCs stored?
|
-
|
Jump to the appropriate DTC table
|
|
7 |
Compare the ECM data values on the scan tool display with typical engine data.
Are the displayed values normal or close to normal?
|
-
|
Go to section "ECM Output Diagnosis"
|
Jump to specified component test
|
8 |
Problem found?
|
-
|
Go to operation 9
|
Jump to operation 10
|
9 |
Repair an open, short to ground, or short to power on the serial data circuit or DLC ignition current circuit.
Has the renovation been completed?
|
-
|
System OK
|
-
|
10 |
Does the scan tool output ECM engine data?
|
-
|
Go to operation 2
|
Go to operation 11
|
11 |
Replace the ECM.
Is the replacement finished?
|
-
|
System OK
|
-
|
ECM Output Diagnosis
Circuit Description
Electronic engine management controller (ECM) controls the operation of most electronic switch components that make up the grounded circuit when turned on. These switches are grouped in groups of 4 and 7 and are referred to as either a 4-way surface mount control module that controls up to 4 outputs, or an output control module (ODM), which independently controls the operation of up to 7 outputs. Not all outputs are used all the time.
The control modules are protected against short circuits. If the relay or solenoid is shorted, due to very low or no resistance, or if the control part of the circuit breaks, too much electrical current may be supplied to the ECM. The control module reacts to this and the output signal either turns off or its internal resistance rises, limiting the electrical current and protecting the ECM and the control module. This results in a high output voltage at the terminals instead of the required low voltage. An open in the circuit from + the battery to this component or in the component itself, or a short to ground in the control part of the circuit, will lower the voltage at the terminals. Any of these conditions is considered a failure in the control module.
The control modules also have a circuit that indicates a voltage dip in the ECM CPU. The scan tool displays the status of the fault loops in the control modules as follows: 0=normal and 1=failure.
Diagnostic Information
The scanning tool is able to control the enabling and disabling of certain components and features. If a component or feature does not support this, run the vehicle under normal operating conditions to check for an open or short circuit.
An open or short to ground indication appears in the open positions on the scan tool only when it is not controlled by the ECM or the scan tool, and a short to voltage is detected in the closed positions on the scan tool only when the component is controlled by the ECM or the scan tool. tool.
ECM Output Diagnosis
Step | Operation | Values | Yes | No |
1 |
Perform a diagnostic system check.
Check completed?
|
-
|
Go to operation 2
|
|
2 |
Connect the diagnostic tool.
Is there a digit of the diagnostic block (DLC) 1 (= malfunction) under any of the numbered positions in the OUTPUT CONTROL MODULES?
|
-
|
Go to operation 3
|
Go to operation 4
|
3 |
Check for an open or short circuit in any of the relevant positions (chains), in which the number 1 appeared and repairs are needed.
Has the renovation been completed?
|
-
|
Go to operation 9
|
Jump to Operation 7
|
4 |
Monitor the output under test with a scanning tool, observing the respective position of each circuit.
Did any of the positions change to 1?
|
-
|
Go to operation 6
|
Go to operation 5
|
5 |
Monitor the output under test with a scanning tool, observing the respective position of each circuit.
With such control, does the component or function work?
|
-
|
Go to operation 9
|
For repairs, go to the appropriate component table
|
6 |
Repair a short to live on the appropriate circuit for the position (chains), marked with the number 1.
Has the renovation been completed?
|
-
|
Go to operation 9
|
-
|
7 |
Disconnect the electrical connector from the component connected to the faulty circuit.
1 is still displayed in the corresponding position of the OUTPUT CONTROL UNIT?
|
-
|
Jump to operation 8
|
For repairs, go to the appropriate component table
|
8 |
Replace the ECM.
Is the replacement finished?
|
-
|
Go to operation 9
|
-
|
9 |
Set the vehicle to the operating mode in the conditions in which it was originally noted.
Is the system now functioning properly?
|
-
|
System OK
|
Go to operation 2
|
Multiple ECM Sensor DTCs Stored
Circuit Description
Electronic engine management controller (ECM) monitors various sensors to determine engine operating conditions. The ECM controls fuel delivery, spark advance, transmission operation, and emission control system operation based on sensor inputs.
The ECM provides ground for all sensors. The ECM supplies 5V through the load resistor and monitors the voltage between the sensor and the resistor to determine the status of the engine coolant temperature sensor (EATING) and intake air temperature sensor (IAT). The ECM supplies the EGR needle position, throttle position, and manifold absolute pressure sensor with a 5-volt pilot signal and a sensor ground signal. The ECM monitors individual feedback from these sensors to determine their operating status.
Diagnostic Information
Be sure to check the cleanliness and security of the ECM mounting and engine ground connection.
A short to voltage on one of the sensor circuits may cause one or more Signal/Input DTCs to set.
If the sensor input circuit is shorted to power, check that the sensor is not damaged. A failed sensor will show a high or low signal after the related circuit is corrected. If the sensor has been damaged, replace it.
An open in one of the sensor circuits causes one or more Low Signal/Input DTCs to set.
A short to ground on one of the sensor circuits causes one or more low signal/input DTCs to set.
Check the following:
- Check the ECM for loose connections. Check harness connectors for terminal connections, poor contact, faulty locks, deformed or damaged terminals, and loose terminal-to-wire connections.
- Inspect the wiring harness for damage. If the harness appears to be OK, note the corresponding sensor's display value on the scan tool with the ignition on and engine off by moving the connectors and wiring harnesses associated with the respective sensors. Changes in the displayed values of the corresponding sensor will indicate the location of the fault.
Multiple ECM Sensor DTCs Stored
Step | Operation | Values | Yes | No |
1 |
Perform a diagnostic system check.
Check completed?
|
-
|
Go to operation 2
|
Go to item "Diagnostic system check".
|
2 |
Problem found?
|
-
|
Go to operation 17
|
Go to operation 3
|
3 |
Problem found?
|
-
|
Go to operation 17
|
Go to operation 4
|
4 |
Measure the voltage of the EGR needle position sensor signal circuit (EGR) between the ECM harness connector and ground.
Is the measured voltage close to the specified value?
|
0 V
|
Go to operation 5
|
Go to operation 9
|
5 |
Measure the signal circuit voltage of the manifold absolute pressure sensor (IDA) between the ECM harness connector and ground.
Is the measured voltage close to the specified value?
|
0 V
|
Go to operation 6
|
Go to operation 11
|
6 |
Measure the voltage of the throttle position sensor signal circuit (TR) between the ECM harness connector and ground.
Is the measured voltage close to the specified value?
|
0 V
|
Jump to Operation 7
|
Go to operation 12
|
7 |
Measure the voltage of the signal circuit of the intake air temperature sensor (IAT) between the ECM harness connector and ground.
Is the measured voltage close to the specified value?
|
0 V
|
Jump to operation 8
|
Jump to operation 13
|
8 |
Measure the voltage of the coolant temperature sensor signal circuit (EATING) between the ECM harness connector and ground.
Is the measured voltage close to the specified value?
|
0 V
|
Jump to operation 16
|
Go to operation 14
|
9 |
Is the measured voltage close to the specified value?
|
0 V
|
Jump to operation 10
|
Jump to operation 15
|
10 |
Replace EGR valve.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
11 |
Locate and repair a short to power in the MAP sensor signal circuit.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
12 |
Locate and repair a short to power in the TP sensor signal circuit.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
13 |
Locate and repair a short to voltage in the IAT sensor signal circuit.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
14 |
Locate and repair the short to power in the ECT sensor signal circuit.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
15 |
Locate and repair a short to voltage in the EGR valve needle position sensor signal circuit.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
16 |
Replace the ECM.
Has the renovation been completed?
|
-
|
Go to operation 17
|
-
|
17 |
Does the scan tool report this diagnostic as passed and passed?
|
-
|
Go to operation 18
|
Go to operation 2
|
18 |
Check for additional DTCs set.
Are DTCs displayed that were not diagnosed?
|
-
|
Go to section "Applicable DTC Table"
|
System OK
|
The crankshaft turns, but the engine does not start
Description of the test
The sequence corresponds to the steps indicated in the diagnostic table.
1. The diagnostic system check prompts the technician to perform basic checks and save the fault status and data to the scan tool. This creates an electronic copy of the data recorded when a fault occurs. The information is stored in the scanning tool for further processing.
1. The diagnostic system check prompts the technician to perform basic checks and save the fault status and data to the scan tool. This creates an electronic copy of the data recorded when a fault occurs. The information is stored in the scanning tool for further processing.
3. When performing a compression test, it can be determined whether the engine has the mechanical ability to run.
2. When performing a compression test, it can be determined whether the engine has the mechanical ability to run.
9. It is important to check for spark on all ignition wires. If there is a spark at one to three terminals of the ignition coil, then the crankshaft position sensor (TFR) fine.
3. It is important to check for spark on all ignition wires. If there is a spark at one to three terminals of the ignition coil, then the crankshaft position sensor (TFR) fine.
19. When checking the ECM output signals at the time of ignition, it is recommended to use an oscilloscope to observe the change in signals. When measuring these output signals with a voltmeter, intermittent faults may occur that are not detected by the voltmeter.
35. This operation verifies the correct operation of the ECM in the fuel pump circuit.
59. This operation tests the ground signal provided by the ECM to control the fuel injectors. If there is no ground signal when cranking, and the fuel injector wiring is normal, then the ECM is faulty.
The crankshaft turns, but the engine does not start
Attention! To prevent electric shock when working with ignition wires while the engine is running, use insulated pliers.
Attention! Do not pinch or kink nylon fuel lines. Defective fuel lines can cause fuel leakage, resulting in fire and injury.
Step | Operation | Values | Yes | No |
1 |
Perform a diagnostic system check.
Check done?
|
-
|
Go to operation 2
|
Go to item "Diagnostic system check".
|
2 |
Check for DTC P0601 setting.
Is the diagnostic trouble code installed?
|
-
|
Jump to the appropriate DTC table
|
Go to operation 4
|
3 |
Rotate the engine crankshaft.
Does the engine start and continue to run?
|
-
|
System OK
|
Go to operation 5
|
4 |
Perform a cylinder compression test.
Compression in all cylinders is equal to or exceeds the set values?
|
689 kPa (100 psi inch)
|
Jump to operation 8
|
Go to operation 5
|
5 |
Check timing belt adjustment.
Has the timing belt been adjusted?
|
-
|
Jump to Operation 7
|
Go to operation 6
|
6 |
Adjust or replace the timing belt if necessary.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
7 |
Repair internal engine defects, if necessary.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
8 |
Check fuel pump fuse.
Fault found?
|
-
|
Go to operation 9
|
Jump to operation 10
|
9 |
Replace fuse.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
10 |
Throttle Position Sensor Readings (TP) below the specified value?
|
1.0 V
|
Go to operation 11
|
|
11 |
Compare engine coolant temperature (EATING) with intake air temperature (IAT).
Is ECT relatively close to IAT?
|
-
|
Go to operation 12
|
|
12 |
Is the MAP sensor reading higher than the set value and fluctuating with cranking?
|
4 V
|
Jump to operation 13
|
Go to operation 14
|
13 |
Rotate the engine crankshaft.
Does the value of the active crankshaft position counter increase when cranking?
|
-
|
Jump to operation 16
|
Go to operation 18
|
14 |
Check scanned data for serial data.
Serial data lost while cranking?
|
-
|
Jump to operation 15
|
Go to item "Checking MAP Sensor Output"
|
15 |
Eliminate voltage loss to the controller (ECM) from the ignition switch.
Has the renovation been completed?
|
-
|
System OK
|
-
|
16 |
Check for spark at all ignition wires when cranking the engine with the starter.
Is there spark at all ignition wires?
|
-
|
Go to operation 41
|
Go to operation 17
|
17 |
Is there spark at all ignition wires?
|
30,000 W
|
Go to operation 3
|
Go to operation 18
|
18 |
Is the measured signal level close to the set value?
|
1.4V (2.5V) *
|
Jump to operation 19
|
Jump to operation 20
|
19 |
Measure the signal level between terminals 2 and 3 of the crankshaft position sensor connector.
Is the measured signal close to the set value?
|
1.4 V (2.5 V) *
|
Go to operation 26
|
Jump to Operation 21
|
20 |
Measure the signal level between the crankshaft position sensor connector terminal 1 and ground.
Is the measured signal level close to the set value?
|
1.4V (2.5V) *
|
Go to operation 22
|
Jump to operation 23
|
21 |
Measure the signal level between the crankshaft position sensor connector terminal 2 and ground.
Is the measured signal level close to the set value?
|
1.4 V (2.5 V) *
|
Go to operation 22
|
Jump to Operation 24
|
22 |
Test for an open circuit in the wire between the crankshaft position sensor connector terminal 3 and ground.
Fault found?
|
-
|
Jump to operation 25
|
Jump to operation 40
|
23 |
Check for an open or short in the wire between the crankshaft position sensor connector terminal 1 and the ECM connector J2 terminal 14.
Fault found?
|
-
|
Jump to operation 25
|
Jump to operation 40
|
24 |
Check for an open or short in the wire between the crankshaft position sensor connector terminal 2 and the ECM connector J2 terminal 15.
Fault found?
|
-
|
Jump to operation 25
|
Jump to 40
|
25 |
Troubleshoot the circuit.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
26 |
Are the signal values close to the set values?
|
1.4 V (2.5 V) * with the ignition on, 1.6 V (2.6 V) * when turning the crankshaft
|
Go to operation 27
|
Jump to operation 28
|
27 |
Measure the signal level at the ECM connector J2 terminal 15 by connecting the ECM connector.
Are the signal values close to the set values?
|
1.4V (2.5V) * with the ignition on, 1.6 V (2.6 V) * when turning the crankshaft
|
Go to operation 29
|
Jump to operation 28
|
28 |
Replace crankshaft position sensor.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
29 |
Is the control lamp on?
|
-
|
Jump to operation 30
|
Go to operation 31
|
30 |
Connect a test lamp to the EI system coil connector and battery positive cable.
Is the control lamp on?
|
-
|
Go to operation 34
|
Go to operation 32
|
31 |
Check for an open circuit in the wire between the ignition switch and terminal 1 of the EI system ignition coil connector.
Fault found?
|
-
|
Jump to Operation 33
|
-
|
32 |
Check for an open circuit in the wire from the electronic ignition system coil to ground.
Fault found?
|
-
|
Go to operation 2
|
-
|
33 |
Is there spark at all ignition wires?
|
-
|
Go to operation 3
|
Go to operation 34
|
34 |
Does the voltage fluctuate within the specified value?
|
0.2-2.0V
|
Go to operation 39
|
Jump to operation 37
|
35 |
While cranking the crankshaft, measure the signal level at terminal 1 of the electronic ignition coil connector.
Does the voltage fluctuate within the specified value?
|
0.2-2.0V
|
Go to operation 39
|
Jump to operation 37
|
36 |
Check for an open in the wire between the EI system ignition coil connector terminal 3 and the ECM connector J2 terminal 35.
Fault found?
|
-
|
Jump to operation 38
|
Jump to operation 40
|
37 |
Check for an open in the wire between the EI system ignition coil connector terminal 1 and the ECM connector J2 terminal 40.
Fault found?
|
-
|
Jump to operation 38
|
Jump to operation 40
|
38 |
Is there spark at all ignition wires?
|
-
|
Go to operation 3
|
Go to operation 39
|
39 |
Replace the electronic ignition coil.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
40 |
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
41 |
Is there fuel pressure?
|
-
|
Go to operation 44
|
Go to operation 42
|
42 |
Is the control lamp on?
|
2 sec.
|
Go to operation 43
|
Jump to operation 53
|
43 |
Replace fuel pump.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
44 |
Is the fuel pressure within the specified value?
|
283-324 kPa (41-47 psi)
|
Go to operation 48
|
Go to operation 45
|
45 |
Fault found?
|
-
|
Go to operation 46
|
Go to operation 47
|
46 |
Is there fuel?
|
283-324 kPa (41-47 psi)
|
Go to operation 3
|
Go to operation 47
|
47 |
Is there fuel?
|
-
|
Go to operation 50
|
Go to operation 51
|
48 |
Check fuel for contamination.
Fuel contaminated?
|
-
|
Go to operation 49
|
Jump to operation 65
|
49 |
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
50 |
Replace fuel pressure regulator.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
51 |
Fault found?
|
-
|
Go to operation 52
|
Go to operation 43
|
52 |
Replace fuel pump sensor, fuel tank filter and/or connecting fuel hoses for blockage.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
53 |
Is the control lamp on?
|
2 sec.
|
Go to operation 54
|
Go to operation 55
|
54 |
Repair the open circuit between the fuel pump connector terminal 5 and ground.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
55 |
Is the control lamp on?
|
2 sec.
|
Go to operation 56
|
Jump to operation 62
|
56 |
Is the control lamp on?
|
-
|
Go to operation 57
|
Jump to operation 61
|
57 |
Is the control lamp on?
|
-
|
Jump to operation 58
|
Go to operation 64
|
58 |
Has the renovation been completed?
|
-
|
Go to operation 2
|
-
|
59 |
Replace fuel cut switch.
Fault found?
|
-
|
Go to operation 3
|
-
|
60 |
Replace fuel pump relay.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
61 |
Fault found?
|
-
|
Go to operation 72
|
-
|
62 |
Test for an open in the wire between the fuel pump relay connector terminal 85 and the ECM connector J1 terminal 51.
Fault found?
|
-
|
Jump to operation 63
|
Jump to operation 40
|
63 |
Repair the wire between the fuel pump relay connector terminal 85 and the ECM connector J1 terminal 51.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
64 |
Repair the wire between the fuel pump relay connector terminal 30 and the positive battery terminal.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
65 |
Does the warning light come on at all fuel injectors?
|
-
|
Jump to operation 66
|
Go to operation 69
|
66 |
Does the warning light come on at all fuel injectors?
|
-
|
Go to operation 67
|
Go to operation 70
|
67 |
Measure the resistance at each fuel injector.
Resistance within the set value (resistance will increase slightly at higher temperature)?
|
11.6-12.4ohm
|
System OK
|
Jump to operation 68
|
68 |
Replace any fuel injectors with a resistance outside the specified range.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
69 |
Repair broken wire (ov) between terminal 1 of the connector (ov) fuel injector wiring harness and engine wiring harness.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
70 |
Fault found?
|
-
|
Go to operation 71
|
Go to operation 73
|
71 |
Repair the open in the fuel injector wiring harness circuit.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
72 |
Replace fuse or repair wiring if necessary.
Has the renovation been completed?
|
-
|
Go to operation 3
|
-
|
73 |
Test for an open circuit from terminal 1 to each of the four fuel injectors and the ignition switch.
Fault found?
|
-
|
Go to operation 72
|
-
|
Malfunction indicator lamp does not work (MIL)
Circuit Description
The Malfunction Indicator Lamp (MIL) should be constantly lit when the ignition switch is in the ON position and the engine is not running. System voltage is applied to the indicator lamp, and the instrument panel serves as a ground conductor. After starting the engine, the instrument panel turns off the malfunction indicator lamp. When a malfunction occurs in the engine management system, the ECM sends a message via high speed GMLAN to the body control module requesting a malfunction indicator lamp. The body control module then sends a message to the instrument cluster via low speed GMLAN requesting that the MIL be turned on.
Description of the test
The number below refers to the stage number from the diagnostic table.
2. If other functions of the instrument panel are disturbed, it is necessary to check the fuse or the presence of voltage supplied to the instrument panel and its grounding.
Malfunction indicator lamp does not work (MIL)
Step | Operation | Values | Yes | No |
1 |
Try to start the engine.
Does the engine start?
|
-
|
Go to operation 2
|
Go to item "Diagnostic system check".
|
2 |
Check the operation of the entire dashboard.
Are all other dashboard functions OK?
|
-
|
Go to operation 3
|
|
3 |
Replace dashboard.
Has the replacement been made?
|
-
|
Go to operation 4
|
-
|
4 |
Turn on the system to check the repair results.
Has the problem been resolved?
|
-
|
System OK
|
Go to operation 2
|
Malfunction indicator lamp (MIL) constantly on
Circuit Description
The Malfunction Indicator Lamp (MIL) should be constantly lit when the ignition switch is in the ON position and the engine is not running. System voltage is applied to the indicator lamp, and the instrument panel serves as a ground conductor. After starting the engine, the instrument panel turns off the malfunction indicator lamp. When a malfunction occurs in the engine management system, the ECM sends a message via high speed GMLAN to the body control module requesting a malfunction indicator lamp. The body control module then sends a message to the instrument cluster via low speed GMLAN requesting that the MIL be turned on.
Diagnostic Information
If the MIL is on steadily and no transmission DTCs are set, an abnormality has occurred in the serial communication circuits.
Malfunction indicator lamp (MIL) constantly on
Step | Operation | Values | Yes | No |
1 |
Have you performed a diagnostic system check?
Check completed?
|
-
|
Go to item "Diagnostic system check".
|