Hi guys need a little help understanding this one. Got a Vauxhall Zafira Z18XE W0L0TGF7532242558 Automatic. Logs crankshaft sensor code P0335 whilst cranking (fault code/light comes on whilst or directly after cranking). I have 1 channel on one of the crank signal wires and another channel on the other signal wire both grounded on battery earth. (ALL ECU powers and grounds measured at ECU whilst cranking/fault occurs are present and correct). Intermittently it will have an extended crank and will always log the fault code in the extended crank. When it starts correctly it will intermittently still log the fault code but not always. Can anyone give me the reason on why in the extended crank I am missing the signal amplitude needed for the computer to "see" the signal and why on a good start I have a good amplitude also the crank and cam signals get pulled down slightly directly after the engine starts (at first i was thinking ECU fault) but the bias voltage on the wire with missing signal (only during cranking) looks good when signal is missing and the fact it only happens when cranking (crankshaft at its slowest speed causing amplitude to be low) makes me think its an air gap issue (free play in crank causing it to float away from sensor?). There is no rust under sensor and it is definitely seated correctly and a new sensor behaves exactly the same. In the waveform the first start is delayed and the second start is good but those weird pull downs can be seen in both. I have Measured signal at sensor and ECU and the signals are identical either end of wire(so not the wiring). HAS ANYONE ENCOUNTERED THIS PROBLEM BEFORE ??? Thank you for your time in advance

Good Afternoon RYM6746
Sorry for my bad English
According to vin it seems to be manufactured in the year 2003


The problem with the P0335 code being registered in the fault memory may be due to the ECU software causing the crankshaft sensor signal to be too weak.
The vehicles affected by this incident are the following models produced:

Astra-G from 2001 to 2003
Corsa-C from 2002 to 2003
Vectra-B from 2001 to 2002
Zafira from 2001 to 2003
Vectra-C from 2002 to 2003

Engine type Z18XE
The manufacturer has distributed a new modified software as of 06-2003, to solve the fault.
No need to replace anything

Hope this can help you

Thanks for the reply. I will try and get the customer back for a software update and keep you posted on the progress. Thankyou

3072 is the latest software. I don’t believe it will fix it.

I see two problems here, no software update will fix this.

There's not much for such an issue, either crank sensor not OEM, aftermarket will not work on this car brand, or also common, defect ecu. We changed in the hundreds of the later, on various problems.

If your replacement sensor was not OE, I¨d try an OE. The sudden dip in the signal happens at the same time on both ckp and cmp sensors.

I would run the test again using the engine as the ground, not the battery. Most vehicles use the engine block as the ECU ground. I've found that I get much "cleaner" waveforms if my scope is grounded close to the ECU ground.

I have a video about this saved somewhere, I'll try and find it and post it up.

https://adaptronicecu.com/blogs/modular ... nding-tips

Sorry this was the video I found very interesting.

Looks like a common impedance issue to me. Especially because it's affecting all three channels.