hello everyone.
I have a 508 RXH hybrid4 that just won't stay running. If I clear all the code with diagbox(9.85) and I remove the traction battery cable from the hybrid battery itselfe ,the car starts for a few second then dies and a lot of errors pop up.After the "small start" I cannot start the car again if I don't cleare all the code again.
These are the error that I need to clear every time in the attacment.
If somebody has any Idea on what to try I'm all ears . All those can errors makes no sense to me.
CAN high mesured 2.7V CAN low 1.6V.
Resistance between High and low 63 Ohm.
Ask me any question you have.
508 RXH CAN Hybrid Network Fault
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Re: 508 RXH CAN Hybrid Network Fault
With these Hybrids, you'll find that the Hybrid ECU is integral to the battery and these often need specialist attention. This can include special procedures for reinitialising the battery / ECU - so unless you know what you're doing I wouldn't try experimenting. You have 13 errors with the Hybrid ECU alone, so I'd bite the bullet and get it to the dealers or a specialist.
Also of note is that your vehicle is nearing 12 years old and the traction batteries in these are really only good for 8-10 years! So I suspect the battery may need replacing, which is about £6500 alone excluding fitting.
Recently saw a BMW e330 - 2.0 litre petrol with hybrid battery, 100k miles on the clock going for under 8k - seems cheap for an 8 year old BMW - but of course the hybrid battery was knackered, so the hidden cost is another £10k to get that replaced!
Also of note is that your vehicle is nearing 12 years old and the traction batteries in these are really only good for 8-10 years! So I suspect the battery may need replacing, which is about £6500 alone excluding fitting.
Recently saw a BMW e330 - 2.0 litre petrol with hybrid battery, 100k miles on the clock going for under 8k - seems cheap for an 8 year old BMW - but of course the hybrid battery was knackered, so the hidden cost is another £10k to get that replaced!
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Marc
Marc
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Re: 508 RXH CAN Hybrid Network Fault
Considering the cost to replace these batteries, it seems absurd they cannot at least run just with the engine.
You might spend upwards the cost of the entire car just replacing batteries twice, if you keep it for it's effective lifespan
You might spend upwards the cost of the entire car just replacing batteries twice, if you keep it for it's effective lifespan

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Re: 508 RXH CAN Hybrid Network Fault
What if I told you that I just fixed the car? Almost one year of trouble. The main fuse for the traction battery: it was not fitted properly. I didn't know that you have to push down the lever part and then push it to le right! After that cleared all the code =car cranks half a turn and starts up like nothing ever happened and STAYS RUNNING.
I'm about to cry. Only god knows how many hour I have wasted searching for broken cable in the CAN network.
If you only push down the main fuse a million errors appears and apparently not even the engine is willing to run. 2 Peugeot dealers have worked on it,I'm jest disgusted. And a mechanic for over a month.
I will put a photo of the main relay for anyone that may have the same problem but it's pretti obvious for those who works on this tipe of car daily( not me I'm a carpenter).
Thanks everyone for the useful info I found in this forum .
I'm about to cry. Only god knows how many hour I have wasted searching for broken cable in the CAN network.
If you only push down the main fuse a million errors appears and apparently not even the engine is willing to run. 2 Peugeot dealers have worked on it,I'm jest disgusted. And a mechanic for over a month.
I will put a photo of the main relay for anyone that may have the same problem but it's pretti obvious for those who works on this tipe of car daily( not me I'm a carpenter).
Thanks everyone for the useful info I found in this forum .
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Re: 508 RXH CAN Hybrid Network Fault
Now you mention it, I do recall someone else having some issue with the fuse - I know that sometimes this has to be reset after the traction battery is disconnected - but glad you have it sorted and saved a few £s.
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Marc
Marc
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Re: 508 RXH CAN Hybrid Network Fault
I tried recreating the problem on purpose , and I did it disconnecting the main fuse and refitting it in the incorrect way and the trouble has come back (engine fault service required), no crank.Also the TBMU gave me a code for a detected impact witch seems logical as the connector is not in all the way.
Than I disconnected the traction battery TBMU and cleared the codes. Trying to start the car it runs for 2 seconds than it dies , and all the CAN related problems appears obviously.
If I fit the main fuse correctly, reconnect the TBMU and clear all codes the car starts right up no problem.
BUT: This makes me think I have another intermittent problem with the HCU1 and HCU2 because the first time I remained stranded in the middle of the road was for an EPB fault. Obviously I completely disassembled the EPB and checked all the cable / assembly and everything is fine . I also bought another EPB ecu that is currently installed.No problem at all with bought of them since that time .
Trying to fix the problem I also disconnected the HCU1 and 2 and the EPB fault came back.
I really think HCU1/2 has become mad for some reason that day and launched a DTC that is permanent and the car was unable to run until that DTC was cleared.
So the result is: almost a year without the car running/2 Peugeot dealers looked at it (and I payed good money) /1 third party mechanic(no result either ) all for one uncleared code.
Really tempted to burn the car down with the two Peugeot dealers,NGL.
Best regard
Than I disconnected the traction battery TBMU and cleared the codes. Trying to start the car it runs for 2 seconds than it dies , and all the CAN related problems appears obviously.
If I fit the main fuse correctly, reconnect the TBMU and clear all codes the car starts right up no problem.
BUT: This makes me think I have another intermittent problem with the HCU1 and HCU2 because the first time I remained stranded in the middle of the road was for an EPB fault. Obviously I completely disassembled the EPB and checked all the cable / assembly and everything is fine . I also bought another EPB ecu that is currently installed.No problem at all with bought of them since that time .
Trying to fix the problem I also disconnected the HCU1 and 2 and the EPB fault came back.
I really think HCU1/2 has become mad for some reason that day and launched a DTC that is permanent and the car was unable to run until that DTC was cleared.
So the result is: almost a year without the car running/2 Peugeot dealers looked at it (and I payed good money) /1 third party mechanic(no result either ) all for one uncleared code.
Really tempted to burn the car down with the two Peugeot dealers,NGL.
Best regard
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Re: 508 RXH CAN Hybrid Network Fault
All I can advise is that it is essential that the ECU parameters are saved using Diagbox before replacing with a new ECU and then transfer them over to the new ECU. A new ECU has to be initialised with Diagbox, so not sure if any of these are causing issues with your vehicle. There's also the circuit breaker (like a disc type thing). But to be honest there are lots of references to voltage absence verifiers and insulation checking equipment (nuclear radiation suits
and the like when dealing with these), so couldn't really advise given the nature of these things.

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Marc
Marc
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Re: 508 RXH CAN Hybrid Network Fault
See that is strange because when I bought the used EPB thinking that it was the real problem(April 2024) I just plugged it in and it worked first try. I just erased the DTC's with an odb2 adapter and my iPhone.
I never programmed that ecu and no one else has.
It came from an identical car just one year younger if I'm correct.
I never understood this part of this story, because everyone I asked told me that it needed to be programmed with diagbox and also under the Peugeot network.
But none the less, the EPB wasn't even the real problem . The original one works just fine... anyway car is fixed call it a win and I won't ask why anymore

I never programmed that ecu and no one else has.
It came from an identical car just one year younger if I'm correct.
I never understood this part of this story, because everyone I asked told me that it needed to be programmed with diagbox and also under the Peugeot network.
But none the less, the EPB wasn't even the real problem . The original one works just fine... anyway car is fixed call it a win and I won't ask why anymore
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Re: 508 RXH CAN Hybrid Network Fault
I have heard of a few people getting caught this way lately. I reckon this is why there is a drop in the number of people buying electric/hybrids. I for one will be avoiding them.GiveMeABreak wrote: 28 Dec 2024, 13:53 With these Hybrids, you'll find that the Hybrid ECU is integral to the battery and these often need specialist attention. This can include special procedures for reinitialising the battery / ECU - so unless you know what you're doing I wouldn't try experimenting. You have 13 errors with the Hybrid ECU alone, so I'd bite the bullet and get it to the dealers or a specialist.
Also of note is that your vehicle is nearing 12 years old and the traction batteries in these are really only good for 8-10 years! So I suspect the battery may need replacing, which is about £6500 alone excluding fitting.
Recently saw a BMW e330 - 2.0 litre petrol with hybrid battery, 100k miles on the clock going for under 8k - seems cheap for an 8 year old BMW - but of course the hybrid battery was knackered, so the hidden cost is another £10k to get that replaced!
Delighted you got it up and running though
Darren
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Re: 508 RXH CAN Hybrid Network Fault
HI,
I'm new to the forum, I might be able to shed some light on this
A couple of years ago I did an EV mastertech course, they mentioned extra contacts on service plugs (may contain a fuse) , inverter drive covers etc, so the systems can detect if the plug/cover/terminal etc is correctly seated.
I have a bit of experience with high voltage drive systems on railway and other equipment. This sort of extra contact is common and usually known as an interlock circuit.
If that sort of terminal was loose and had full power flowing a fire would quickly result, which is why some sort of safety interlock is used.
I'm surprised the dealers didn't go through the manufacturers 'safe isolation' procedures, which would have found the unseated connector.
I would go back to the dealers and ask for details of their EV training.
I would suggest being VERY carful around any of these ORANGE coloured components, seek training
mistakes around High Voltage DC WILL KILL YOU ,
and is much more dangerous than house hold AC supply ,
There is no RCD & no second chances
I'm new to the forum, I might be able to shed some light on this
A couple of years ago I did an EV mastertech course, they mentioned extra contacts on service plugs (may contain a fuse) , inverter drive covers etc, so the systems can detect if the plug/cover/terminal etc is correctly seated.
I have a bit of experience with high voltage drive systems on railway and other equipment. This sort of extra contact is common and usually known as an interlock circuit.
If that sort of terminal was loose and had full power flowing a fire would quickly result, which is why some sort of safety interlock is used.
I'm surprised the dealers didn't go through the manufacturers 'safe isolation' procedures, which would have found the unseated connector.
I would go back to the dealers and ask for details of their EV training.
I would suggest being VERY carful around any of these ORANGE coloured components, seek training
mistakes around High Voltage DC WILL KILL YOU ,
and is much more dangerous than house hold AC supply ,
There is no RCD & no second chances
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Re: 508 RXH CAN Hybrid Network Fault
Officially they do - There are very detailed procedures and I have only mentioned a few specifics as this sort of thing is really beyond the scope of a Forum given the risks and hazards of dealing with EV and Hybrid batteries and associated equipment - and as you elude to requires specific training and specialist equipment. They don't release this sort of thing to the public for this very reason - and often refer you to the dealer.
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Marc
Marc
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Re: 508 RXH CAN Hybrid Network Fault
Hi Marc
Thanks for the like,
Presumably the OP's car was not driving and recovered to the dealer,
This sort of unclipped connector is the sort of thing training/quality assessors would
do on a test car & send it to a workshop.
Safe isolation / reinstatement procedures would have cleared this fault.
I would suggest returning to the dealer and asking for a refund.
And asking who their certified techs are & who did their training,
The IMI (IMI TECHSAFE) keep a register of certified techs (currently voluntary) , the can and DO revoke certificates,
As far as I know , none in the motor industry has been killed working on an EV , but it WILL happen sooner or later.
Thanks for the like,
Presumably the OP's car was not driving and recovered to the dealer,
This sort of unclipped connector is the sort of thing training/quality assessors would
do on a test car & send it to a workshop.
Safe isolation / reinstatement procedures would have cleared this fault.
I would suggest returning to the dealer and asking for a refund.
And asking who their certified techs are & who did their training,
The IMI (IMI TECHSAFE) keep a register of certified techs (currently voluntary) , the can and DO revoke certificates,
As far as I know , none in the motor industry has been killed working on an EV , but it WILL happen sooner or later.
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Re: 508 RXH CAN Hybrid Network Fault
I deal in hybrid4s and they have lots of issues, I just re read the thread and was going to suggest the battery isolation switch, as in global test it was showing traction battery no communication, glad you found it but how did it work loose? I've got 5 of these in the yard all with issues relating to the hybrid system.
The battery contains its own ecu
Hcu 2 is the charger unit under the battery
Hcu is the reverse alternator
Hcu2 requires online telecoding if you replace it
Traction batteries are plug and play
Alternators need programing if replace for a second hand one they don't if it's your unit and you've just had the bearing replaced, alternator programming needs 20% Traction battery charge.
The battery contains its own ecu
Hcu 2 is the charger unit under the battery
Hcu is the reverse alternator
Hcu2 requires online telecoding if you replace it
Traction batteries are plug and play
Alternators need programing if replace for a second hand one they don't if it's your unit and you've just had the bearing replaced, alternator programming needs 20% Traction battery charge.
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Re: 508 RXH CAN Hybrid Network Fault
Hi,
Quote
'glad you found it but how did it work loose?'
Quote
'I didn't know that you have to push down the lever part and then push it to le right! '
Seems like someone pulled the isolation link and just didnt get it locked in again fully,
Mr-white spotted it from pic of a global scan , 'no battery communication' sent him stright in that direction.
Bit like old Diesel mechanics know to check 'filters first', with high voltage drive sysyems confirming interlocks is a basic check.
Dealer techs should know this, I know there is a shortage of techs but better to wait for the like of mr-white , than get 'two dealers and an independant' miss an isolator not lateched and presumably charge for it?
Techsafe is searchable so customers can find them.
https://tide.theimi.org.uk/membership/p ... l-register
Quote
'glad you found it but how did it work loose?'
Quote
'I didn't know that you have to push down the lever part and then push it to le right! '
Seems like someone pulled the isolation link and just didnt get it locked in again fully,
Mr-white spotted it from pic of a global scan , 'no battery communication' sent him stright in that direction.
Bit like old Diesel mechanics know to check 'filters first', with high voltage drive sysyems confirming interlocks is a basic check.
Dealer techs should know this, I know there is a shortage of techs but better to wait for the like of mr-white , than get 'two dealers and an independant' miss an isolator not lateched and presumably charge for it?
Techsafe is searchable so customers can find them.
https://tide.theimi.org.uk/membership/p ... l-register