P38A Massive problem

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tarphenry said:
Hi I have reached the end of my skill set with this problem, My problem is that the BECM talks to the HEVAC and the HEVAC talks to the suspension So either the HEVAC is buggered or the BECM is. the number of functions that are initiated through the HEVAC is amazing. I forgot to get the no of the HEVAC unit but I will tomorrow and would like to borrow your spare HEVAC for a day if thats ok. Thank you
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Not a problem..just had a look and my spare is AWR1012.
 
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Just spent an hour removing unit only to find i only got LR part no will take it out again and look for AWR no. typical of me to do the job £3TIMES
 
tarphenry said:
Just spent an hour removing unit only to find i only got LR part no will take it out again and look for AWR no. typical of me to do the job £3TIMES
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No problem put the number you have on.
 

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I will have another look tomorrow thanks your LR part no is1012 and my IND no should read B not 8
 
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Hi, It seems that your unit will not run on my car but many thanks anyway. What I need is someone who can test and if necessary repair my unit. Thanks to all for your help. another 2 days and it could well be time for the swan vestas
 
tarphenry said:
Hi I have reached the end of my skill set with this problem, My problem is that the BECM talks to the HEVAC and the HEVAC talks to the suspension So either the HEVAC is buggered or the BECM is. the number of functions that are initiated through the HEVAC is amazing. I forgot to get the no of the HEVAC unit but I will tomorrow and would like to borrow your spare HEVAC for a day if thats ok. Thank you
Click to expand...

HEVAC does not specifically "talk" to the suspension or the BECM. It does have Input Signals from the BECM for AC Grant, Engine Speed & Illumination Dimmer. Outputs are signal lines for front & rear heated screens that trigger the relevant relays, although these also tell the engine ECU to expect increased load from the alternator !
 
I am not electrically minded ,but from what I read the HEVAC unit supplies power to " wake up" the air suspension ECU. I may have mis understood but thats how I read the information.
 
tarphenry said:
I am not electrically minded ,but from what I read the HEVAC unit supplies power to " wake up" the air suspension ECU. I may have mis understood but thats how I read the information.
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That sounds right. I seem to recall Marty saying old units grounded through the unit to pull the AC on but newer ones had a small current that pulled a relay to do the job. Some of the replacement units are able to do both but a later (original) car unit fitted to an early car cannot handle the current and will break.

I suspect Marty can fix them but as far as I know he's still in NZ.
 
Yes they changed the electrics around on later models with different fuse layouts like where the starter runs through a separate circuit. Some hevacs pull the clutch others power a relay
If it can be fixed Marty can do it but has been awol some time
 
tarphenry said:
yes Martys away at the moment as there is no work here for him.I have ordered another Hevac unit to test the system. It will be here Wednesday .I will solve the problem eventually.
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Is this the new car? Did they check the chassis number to make sure someone hasn't previously replaced it with the wrong unit?
 
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