Crankshaft position sensor error
 

Hi,

The check engine light has been lighting on my Accord 2.0 iS 1994 lately. The problem was intermittent earlier but now it has become a regular feature for around last one month. Shunting the diagnostic switch revealed error code 4 => crankshaft position sensor. Clearing the error does not help since the light comes on in a couple of drives.

I also checked the resistance for the sensor (from 8P connector located close to engine) and it came out to be in the correct range. By the way, the thermostat sensor was changed by a mechanic before this problem showed up. I have a feeling that this could be a connected problem since both sensors have pins in the same connector.

Any ideas about the actual problem and how to correct it ? Please do mention the location of parts/sensors/cables.

Thanks,
Arif

Welcome new member! Where are you? UK?

Resistance of that sensor is only part of the story. You can watch the signal waveform with an oscilloscope, but there's not lot of detail about what it's SUPPOSED to look like.

The CKP sensor is in the distributor, along with CYP & TDC. The sensors don't seem to be available separately, so you have to buy a new distributor. That's a lot of $$$ to replace without confirming diagnosis. If you can find one to borrow that would be good.

If you remove the distributor cap, & the plastic shroud covering the internals, look for the RED DUST. If there's rusty red dust in there, that can confirm you need a new distributor.

Also, you can verify good continuity through the wiring back to the ECU. I never owned a 94 Accord, so not really sure the details. Pinched or cut wiring harness is a real pain to check out, because it can be anywhere.

I think there's a big cluster of ground wires bolted down near the thermostat, so you should check for them being loose/dirty/corroded.