We begin checking the injector control circuits by checking the integrity of fuse F14 (15A) of the mounting block located in the passenger compartment.
Failure of fuse F14 can also be caused by a malfunction of the generator circuits, vehicle speed sensor, canister purge valve, or exhaust gas recirculation valve.
We replace the faulty fuse with a new one, having first checked whether there is a short circuit to ground at the front terminal of the fuse socket in the mounting block.
To check the power supply circuits of the injectors (power "+") with the ignition off, disconnect the pads (4 pcs) of the wiring harness from the injectors.
With the ignition on…
…we measure the voltage between terminal "1" and the engine "ground" for each injector.
The device should record a voltage equal to the voltage of the vehicle's on-board network.
We also check the serviceability of the injector control circuits (open or short to ground) between terminal "2" of the wiring harness connector of each injector and the corresponding terminal of the ECU wiring harness connector for each cylinder: 1st cylinder - terminal "M25"; 2nd cylinder - terminal "M22"; 3rd cylinder - terminal "M24"; 4th cylinder - terminal "M11".
To check the injector winding with the ignition off, disconnect the engine control system wiring harness connector from it (see Removal the fuel rail and injectors).
Having connected the tester probes to the injector terminals…
…we check the winding resistance.
A serviceable injector should have a winding resistance of 11.6–12.4 Ohms.
To check the functionality of the injector, the quality of the spray and the tightness of the sprayer, remove the fuel rail (see Removal the fuel rail and injectors).
We connect the tip of the pressure line tube to the ramp fitting, and the tip of the drain line tube to the fuel pressure regulator branch pipe.
We install the fuel pump fuse in place.
We check each injector one by one, placing a container underneath it to collect the fuel.
After turning on the ignition, we directly supply 12 V voltage from the battery to the injector terminals using two wires.
The operation of checking the quality of fuel atomization by the injector is fire hazardous.
Avoid sparking when applying voltage to the injector.
The fuel jets should emerge from the injector nozzle with a characteristic spray cone.
After disconnecting the wires from the injector, we check whether fuel is leaking through the holes of the injector nozzle.
Fuel leakage should not exceed one drop per minute.
We check other injectors in the same way.
If the electrical resistance of the injector winding does not correspond to the norm, the amount of injected fuel and the spray pattern differ greatly from the indicators of other injectors, or the injector is leaky, it must be replaced.