Contents: Signs of malfunction - instrument… ↧ The instrument cluster does not work ↧ Engine coolant temperature gauge is… ↧ Fuel gauge shows inaccurate data or… ↧ Inaccurate readings or speedometer… ↧ Inaccurate readings or tachometer… ↧ The sound alarm is constantly on ↧
Signs of malfunction - instrument panel, indicators
Important: Before using the symptom charts, you must complete the following steps.
1. Before using the symptom charts, perform a vehicle system diagnostic check to verify the following points are true.
- There are no fault codes.
- Controllers can communicate via a serial communication line.
2. View the system operation to become familiar with the system's functions.
Visual inspection / physical control
- Inspect for aftermarket equipment that may affect the operation of the instrument cluster or warning sound systems.
- Inspect easily accessible and visible parts of the system for obvious signs of damage or conditions that could lead to malfunction.
- Make sure the fluid level is normal.
Intermittent faults
Faulty electrical connections or wiring may cause intermittent faults. Refer to "Checking for Intermittent Failure and Poor Connector Contact" in Section 9A, "Body Wiring System".
The instrument cluster does not work
Information on troubleshooting
- Before performing the diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The instrument cluster (IPC) is supplied with voltage by the battery voltage circuit and the ignition 1 voltage circuit. The IPC operates when the ignition 1 voltage circuit is in the RUN/START condition.
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
1. Turn off ignition, disconnect IPC instrument cluster.
2. Turn on the ignition, make sure that the test lamp connected between the ignition voltage circuit 1 and ground lights up.
- If the test lamp does not light, eliminate the short to ground or high resistance in the ignition voltage circuit 1.
3. Verify that the test lamp illuminates between the ignition 1 voltage circuit and the IPC instrument cluster ground circuit.
- If the test lamp does not illuminate, repair the open or high resistance in the IPC instrument cluster ground circuit.
- If the indicator lamp illuminates, replace the IPC instrument cluster.
Repair instructions
Perform a post-repair diagnostic check upon completion of the diagnostic procedure.
Controller information for replacement, setup and programming of IPC and PCM.
Engine coolant temperature gauge is inaccurate or does not work
Information on troubleshooting
Important: Before performing each diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The instrument cluster (IPC) displays engine coolant temperature using data from the engine control module (ECM). The ECM sends temperature data via the GMLAN serial data line to the body control module (BCM). The BCM sends GMLAN data to the IPC to control the engine temperature gauge and display engine coolant temperature.
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
Turn on the ignition, check the engine coolant temperature gauge over its entire range using a diagnostic tool.
- If the engine coolant temperature gauge does not move through its full range from low to high, replace the instrument cluster (IPC).
Repair instructions
Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.
Information on the controller for replacement, setup and programming of the IPC instrument cluster.
Fuel gauge shows inaccurate data or does not work
Information on troubleshooting
Important: Before performing each diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The fuel level sensor changes resistance depending on the fuel level. The engine control module (ECM) monitors the fuel level sensor signal circuit to determine the fuel level. When the fuel tank is full, the sensor resistance is low and a low voltage signal is sent to the ECM. When the fuel tank is empty, the sensor resistance is high and a high voltage signal is sent to the ECM. The fuel level sensor signal circuit is used by the ECM to calculate the percentage of fuel remaining in the tank.
The ECM controller transmits fuel balance data via a serial link to the instrument cluster for controlling the fuel level indicator. Fuel level data is also used to diagnose the flash skip and Fuel Vapor Capture system (EVAP).
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
1. Turn ignition off, disconnect CXXX, connect signal generator and instrument cluster tester between signal circuit and low reference circuit.
2. Turn on the ignition, change the resistance on the signal generator from 40 to 250 Ohm and observe the fuel level indicator.
- If the fuel gauge indicates the correct fuel level, test the signal circuit for an open or high resistance between CXXX and the fuel level sensor. If the circuits are normal, test the low reference circuit for an open or high resistance between CXXX and the fuel level sensor.
- If all circuits are OK, replace the fuel level sensor.
3. Turn on the ignition, change the resistance on the signal generator from 40 to 250 Ohm. Make sure that the parameter "Level of remaining fuel in the tank" displays the correct value of the percentage of fuel remaining in the tank.
- If the fuel level is displayed correctly, replace the instrument cluster (IPC).
- If the fuel remaining value is not correct, test the signal circuit for an open or high resistance. If the circuits are normal, test the low reference circuit for an open or high resistance.
- If all circuits are normal, replace the ECM.
Repair instructions
Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.
- "Replacing the Fuel Level Sensor" in Section 1F2, "Engine Controls - FAM II 2.4D".
Inaccurate readings or speedometer and/or trip meter not working
Information on troubleshooting
Important: Before performing each diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The instrument cluster (IPC) displays vehicle speed based on data from the engine controller (ECM). The ECM converts the vehicle speed sensor data into a 4,000 pulses per mile signal. The PCM sends vehicle speed data over the GMLAN serial data line to the body control module (BCM). The BCM sends GMLAN data to the IPC to control the speedometer pointer and display vehicle speed and mileage.
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
1. Turn off the ignition and lift the drive wheels of the vehicle.
2. Start the engine, put the gearbox in the driving position, check that the "vehicle speed sensor" parameter on the diagnostic device matches the speedometer readings.
- If the "vehicle speed sensor" parameter does not match the speedometer reading, replace the IPC instrument cluster.
- If the odometer is not working properly, replace the IPC instrument cluster.
Repair instructions
Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.
Inaccurate readings or tachometer not working
Information on troubleshooting
Important: Before performing each diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The instrument cluster (IPC) displays engine speed based on data from the engine controller (ECM). The ECM converts data from the vehicle speed sensor into a signal of 2 pulses per engine crankshaft revolution. The ECM sends engine speed data via a serial data line to the body control module (BCM). The BCM sends GMLAN data to the IPC to control the tachometer pointer and display engine speed.
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
Turn off the ignition and lift the drive wheels of the vehicle.
- If the tachometer pointer does not move through the entire range from the lower to the upper position, replace the instrument cluster (IPC).
Repair instructions
Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.
The sound alarm is constantly on
Information on troubleshooting
Important: Before performing each diagnostic procedure, perform a diagnostic check of the vehicle system.
Description of the circuit/system
The audio system continuously sounds an audible warning tone through the left front speaker. The audio system receives commands to sound the warning tones via the serial communication line from the body control module (BCM).
Electrical information
- Checking the chain
- Repair of the connector
- Checking for intermittent faults and contact problems in connectors
- Wiring repair
Circuit/system check
1. Turn ignition on, headlight switch to OFF position, ensure that the "Headlight Switch" parameter on the diagnostic tool shows inactive state.
- If the switch is inactive, check the headlamp signal circuit for an open or short to supply voltage. If the circuit is OK, replace the headlamp switch.
2. Turn off the ignition, remove the key from the ignition switch, and ensure that the "Key Inserted into Ignition Switch Status" parameter on the scan tool shows that the key is removed.
- If the parameter does not indicate that the key is removed, check the signal circuit of the key removal control switch for an open or short to supply voltage. If the circuit is OK, replace the ignition switch.
3. Turn off the ignition, remove the key from the ignition switch, and ensure that the "Key Inserted into Ignition Switch Status" parameter on the scan tool shows that the key is removed.
- If any of the parameters show "Door is slightly open", go to the section "Entrance lights are constantly on".
- If all parameters show "Door Closed", replace the BCM controller.
Repair instructions
Important: Perform a post-repair diagnostic check upon completion of each diagnostic procedure.
- Replacing the ignition switch
- Replacing the multi-function turn signal switch.