2007 range rover CAN bus waveform disruption

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wade0059
OneWave
OneWave
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Joined: Sun Jul 29, 2018 8:04 am

Re: 2007 range rover CAN bus waveform disruption

Post by wade0059 »

again thank you for your replies. yes Steve you were right the communication errors were being caused by the fault.
Sorted, behind the heads the transmission loom had a wiring loom clip off. The loom was sitting against the egr pipe, a tiny part of the insulation on a wire had melted allowing it to occasionally earth out. Took a fair while to rectify as access was an issue. I really should have found this faster! but hey ho its sorted now.
Thank you to all took the time to reply i really appreciate all help

liviu2004
TwoWaves
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Re: 2007 range rover CAN bus waveform disruption

Post by liviu2004 »

It doesn’t make sense, that waveform is not short to ground 100% guaranteed.
Grounded can signal will go to 0, I can prove that anytime.

Steve Smith
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Re: 2007 range rover CAN bus waveform disruption

Post by Steve Smith »

Nice work and thank you to all.

I agree that CAN shorted to an EGR pipe should bring about a short to zero volts and pull the CAN Bus down to ground.

Reading through, it may not have been a CAN wire shorted to the EGR pipe but wiring responsible for the operation or position of Transmission Range change.

It would appear once this fault occurred (so flagging P0902) that the relevant ECU responsible for this code produced the behavioral characteristics on the CAN line in the original post

Its food for thought for sure.

Great work and thank you for the feedback

Take care......Steve

wade0059
OneWave
OneWave
Posts: 11
Joined: Sun Jul 29, 2018 8:04 am

Re: 2007 range rover CAN bus waveform disruption

Post by wade0059 »

Yes sorry I should have been more clear, it wasn't a Can line shorting out.
I've since taken the car on a few test drives probably totalling 20 miles. I still have the strange irregularities in the Can H/Can L yet I have no communication faults or fault codes. So am a little confused on that aspect

liviu2004
TwoWaves
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Joined: Sat Mar 19, 2016 8:23 am
Location: Netherlands

Re: 2007 range rover CAN bus waveform disruption

Post by liviu2004 »

I had worse on a zafira a still no faultcodes, reason, messages are retransmitted so fast, that there is no reason to flag comm fault just for 1 can message.

wade0059
OneWave
OneWave
Posts: 11
Joined: Sun Jul 29, 2018 8:04 am

Re: 2007 range rover CAN bus waveform disruption

Post by wade0059 »

thank you that's good to know

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