Series 2 Diagnostic Socket, fault code reading

[colinxm]

Hi all, has anyone here got any information on retrieving fault codes from the series 2 diagnostic socket under the dash - any information would help ! It used to be a doddle on the series ones but i'm stumped with this one and don't want to have to spend a fortune on dedicated diagnostic equipment...

Thanks Colin.P

[noz]

Hi Colin,

In the early series 1 ecu's you could bridge one of the pins to ground and use an LED on another pin to indicate a number of lashes to represent the stored fault. There's a file in the 'self help' section showing you how to do this. In the same time period the rest of the world (except the PSA) were getting themselves organised around OBD which has now become a mandatory comms protocol for anyone selling a new car. What it means is that any third party developer can develop an interface using publicly available datasheets to get information out of the ecu and sell the interface to the general public. This prevents the car manufacturer from monopolising the ecu and preventing third party access and maintenance. The PSA resisted this legislation fro as long as they could because they used their own protocol(s). These were called CAN (Controller Area Network) and VAN (Vehicle Area Network). Eventually PSA did capitulate but had manufactured a good few thousand cars by that time implementing CAN and VAN.

An ecu communicating in CAN or VAN does not lend itself to the shorting and LED trick. The proprietry computers like Lexia, Elit, Saouris etc which garages typically have are required to get the information out of the ecu. I have long considered making my own interface. You can even get USB-CAN interfaces off the shelf now. The protocol is widely published and is no secret. However, the codes and their meanings are not. Having said that, we do have access to an Elit through one of the club members. Although not capable myself I feel it must be possible to put a packet sniffer on the comms line between the Elit and the ecu and decipher the datastream knowing which buttons you are pressing and the information displayed on the screen.

Does anyone here have that sort of knowledge or capability?

That's a long winded way of saying its not possible Colin, sorry.

cheers

noz