Cars an MY 99 and since I've had it I occasionally get knock sensor CEL - only when pottering around. Doesn't depend on petrol type used, and appears fairly random. I have replaced at some time or other the knock sensor, MAF and lambda sensors.

Currently the car appears to be surging and slightly misfiring under light load. Also the CEL appears on more than normal. Taking the spark plugs out showed the two front ones were very clean and the two rear slightly more sooty around the base of the thread. I thought that perhaps injectors but then I realised that you have one coil for the rear and one coil for the front cylinders (or at least it looks like it). Is it likely the coil pack is gone on one coil causing a misfire and slightly sooty plugs? Would that trigger a knock sensor CEL though?

I'll post a pic when I get home.

 

Forgot to mention I've even swapped the ECU it behaves exactly the same.

 

The 99 does occasionally fail the coil pack, and yes one of the 2 coils serves the 2 rears, so its likely either that coil is on its way out or the wiring to it has a problem.

Simon

 

Cheers,

I got home and pulled it off and getting MegaOhms for all combinations of connections onto the 4 wires (not sure ofthe pinout) and no connection(over 20 MegaOhms) between any ignition lead terminal to any pin on the connector. It doesn't sound healthy but I wondered if there were some diodes in it too?

Anyone with an MY99 coilpack lying around to test with a volt meter??

 

Bump

Anyone with an MY99 coilpack lying around to test with a multimeter??

 

Ok for anyone that is interested I think these coil packs have the ignition amplifiers built in which is why they test out funny.