First attempt

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Location: Near Wigan

First attempt

Post by steve-amt » Sun Jan 31, 2016 9:38 pm

Hello everyone.

Just getting into diagnostics got a 4425, Experimenting on mates van. Vauxhall combo DIESEL Z17DTH engine. As van is new to him he put a cam belt on it. While refitting cover the 5 steel pegs on the cam pulley got bent away from the cam sensor, so he bent them back to where they appear to be ok. Keeps getting a P code can't recall the numbers but was cam sensor signal improbable.

I used a dvom to try to establish circuit but with koeo & sensor both plugged in and out and testing the harness side (3 wire) pins 1 & 3 have 5 volts even unplugged. Pin 2 has nothing at all. So I back probed pin 2 and got a waveform. I will try and post it bear with me.

The cam pulley has 5 pegs that pass the sensor 2 are almost together the other 3 are even around the pulley as you would expect. You can see this on the waveform. BUT the single peg just before the double ones shows to be thinner than all the others. I managed to measure with the rulers the time of the legs and all were around 1.45 ms except the thin one was 840 micro secs about half the width (Time) of the others.

I examined the pins and found the suspect one to be further away from the sensor and twisted, so I bent it straight. However by the time I had realised and done this we were packed up so I didn't get an after waveform.

The van will be back shortly as there is also a P1105 atmospheric pressure sensor malfunction. I'll get waveform then.

Any comments or telling offs would be appreciated. What do you think? am I thinking in the right way?

Vauxhall_Combo Tour_2005_Diesel_20160125-0001.psdata
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Fat Freddy
Posts: 318
Joined: Fri May 04, 2012 4:52 am

Re: First attempt

Post by Fat Freddy » Sun Jan 31, 2016 11:59 pm


Have you checked the library for a known good.

You really need a crank sensor signal on this capture.

FWIW I had a similar problem with a damaged tone wheel on an Astra (no one ask :oops: It wasn't my idea LOL). The fix was not as expected but as I'm not sure why (Chasing down the original fault sorted out the introduced fault. Coincidence could be :shock: :? ) I'm not going to add confusion to this issue - Yet :) :twisted:


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