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Old 9th December 2018, 12:27   #51
SD1too
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I would like to know how exactly the CAN bus is involved in the operation of the HRW.
Thank you very much Phil for your clear and concise answer to my question.

So it's the "engine running" signal which the ECM sends on the CAN bus which is necessary for the HRW to operate*. That's virtually the same principle used on my 34 year old SD1 so well done cb750Chris for spotting it. All the talk about fuel burning heaters and external temperature sensors was unfortunately irrelevant to the problem, but interesting nonetheless.

Simon

* Located in RAVE Air Conditioning, Description & Operation 82-25: "Rear window heater switch: Enabled while the engine is running".
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Last edited by SD1too; 9th December 2018 at 13:10.. Reason: Adding *
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Old 9th December 2018, 12:37   #52
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Why not check the data traffic yourself Simon, I'm sure you could rig up an oscilloscope...
Well, thanks for the suggestion Brian but I was asking you following your declared expertise:
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Of course I know Simon, there is a very good reason I am sole supplier of remanufactured diesel ECM modules to X-Part, and it's not because I'm wet behind the ears when it comes to the electronic systems on these cars.
It's strange that you didn't provide the answer that Phil has.

Simon
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Old 9th December 2018, 13:24   #53
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Seems like you have a sensor that fails when it gets cold.
Or it's the ECM itself being affected by the cold (two possibilities).

Simon
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Old 9th December 2018, 20:11   #54
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Or it's the ECM itself being affected by the cold (two possibilities).

Simon
Bit of cosy Bubble Wrap perhaps for the ECM. Keep the damp off too with drop of WD 40 squirted in it.---Lol.
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Old 9th December 2018, 20:16   #55
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So, my next thing to do it's to try to change the NEC IC from the spare ECU to the main one. If I mess this up, I need to buy a new ECU anyway.

I saw 2 useful videos on YT - THIS and THIS

I need to know for sure if the NEC IC is responsible for canbus failure and not to change it for no purpose.
I'm talking about THIS ONE

If someone has a better photo with it, I would be grateful!
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Old 9th December 2018, 20:27   #56
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So, my next thing to do it's to try to change the NEC IC from the spare ECU to the main one. If I mess this up, I need to buy a new ECU anyway.

I saw 2 useful videos on YT - THIS and THIS

I need to know for sure if the NEC IC is responsible for canbus failure and not to change it for no purpose.
I'm talking about THIS ONE

If someone has a better photo with it, I would be grateful!
You don't want to attempt changing that IC, change the 95P08 security eeprom instead.

The car will work normally afterwards

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Last edited by marinabrian; 9th December 2018 at 20:35..
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Old 9th December 2018, 22:25   #57
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Thanks!
That disables the immo, right?
If my spare ECU is THIS

And my main ECU is THIS

They are compatible even if the codes are not the same?
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Old 9th December 2018, 23:29   #58
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Thanks!
That disables the immo, right?
If my spare ECU is THIS

And my main ECU is THIS

They are compatible even if the codes are not the same?
It doesn't disable the immobiliser, it does transfer the rolling code so it will start.

Both ECM are NNN100692 so non EOBD manual versions, so swapping the 95P08 will work

Brian
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Old 10th December 2018, 00:44   #59
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Originally Posted by COLVERT View Post
Seems like you have a sensor that fails when it gets cold.


( Bit like me really. Lol. )---
The only sensor that could fail that would effect the Rev counter reading then would be the crank sensor and if this were to fail the engine would not start, or if it failed while running the engine would cut out

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Or it's the ECM itself being affected by the cold (two possibilities)
Simon
The ECU isn't prone to this, the Can-bus controller failure happens at any time of year or temperature. On ECU'S that have experienced this failure the fault is permanent it doesn't get better if the ECU is allowed to dry in a warm environment.

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Bit of cosy Bubble Wrap perhaps for the ECM. Keep the damp off too with drop of WD 40 squirted in it.---Lol.
Don't ever squirt WD40 into an ECU it can often cause far more problems than it fixes, I've had to replace quite a few where someone has sprayed something into an ECU in order to try and protect it.
There's not really any room for bubble wrap and all it will do is trap any dampness that managed to get in there


Russ
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