No comms with cph and non starter (Xantia)

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trapa57
Donor 2020
Posts: 26
Joined: 26 Sep 2013, 12:30
x 2

No comms with cph and non starter (Xantia)

Post by trapa57 »

Hello All,

My (until very recently) very reliable hdi 110 Xantia will not start. Engine cranks, fuel pump whirrs (it is a new one) but there is no communication with the cph. The summarised back story is: the Xantia has not been running well recently, and I was just short of replacing the EGR. To test the EGR theory I connected the vac pump to the turbo, moved the car out of the garage, switched it off and shut the garage door. When I returned to the car about 2 minutes later it would not start. As I had swapped out the low pressure pump 6 years ago for another from a dead estate on the drive I replaced the pump with a new Bosch one. However, this has not solved the problem and after a couple of Lexia sessions I realised I have no communications with the cpf - it says 'no' when I carry out a general diagnostic session and generally (although not always) does not make communications when I carry out a specific cph diagnostic.
i have tried all 3 of the keys I have and also tried one of the keys but with another pcb (from the dead estate). In each instance there is dash light and no beep, so I am suspect the immobiliser aerial may be faulty.
What do you suggest should be my next step?

Thanks,

Paul
wheeler
Posts: 5112
Joined: 21 Sep 2002, 19:07
x 290

Re: No comms with cph and non starter (Xantia)

Post by wheeler »

If the aerial had failed you would still get rapid flashing of the key light & beeping, also this would not cause lack of comms with CPH. if there is no coms with it you need to check its power supplies & earths first. If you do a forum search you should find a wiring diagram as im sure ive posted them a few times. Have you checked all the fuses?
Are you getting coms with the injection ECU?
trapa57
Donor 2020
Posts: 26
Joined: 26 Sep 2013, 12:30
x 2

Re: No comms with cph and non starter (Xantia)

Post by trapa57 »

Thanks Wheeler, you were spot on. I started by cleaning the earth points next to the battery and the one below the airbox. No joy. I then checked all the fuses starting in the engine compartment and working my way round the fuses in front of the driver and hey presto F2 had blown. When replaced the car started. Another Lexia sessions to clear the faults but one remains - 'Communication ithe siren impossible'. I suspect that will be the cause of the blown fuse (I seldom alarm the car so hadn't noticed) so will investigate over the weekend.