Was running perfect, it was accelerating it sputtered then stopped running?

RHLLOYD

MEMBER
2002 SUBARU WRX
2.0L
4 CYL
4WD
AUTOMATIC
75,000 MILES

After checking all the sensors and relays, fuel, replacing the timing belt (just because) spark plugs, coil packs, cam crank sensors replaced, alternator replaced, map sensor replaced, all fuses checked. Driver side 2 and 4 are not producing spark, but 1 and 3 are, when cranking the engine. How is this possible the one bank is sparking and the other not? Is the ECM directly responsible to allow the spark? Better yet from the coil pack back to the ignition is there anything that interrupts one side over the other? It would appear the 2 banks are separated somehow. Maybe this is where the problem lays? If so, where is this where? One last thought can the brown relay behind the kick panel on the passenger side be the suspect. I'm thinking only one half internally is functioning causing the one side sparking and the other not?

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
42,912 POSTS

So, the ignition coils are run by the PCM so it could be out, but I noticed there are two ground wires one for each side of the coils for the engine. These grounds are located on the right rear of the engine. Here are the wiring diagrams for the coils so you can see for yourself. If the grounds are okay here is how to change the PCM out because the coil drivers for one side have stopped working. Please check the images below and let us know what happens.

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