Hello, I hope I can offer you some assistance.
Is this an early or later shape 02 Fiesta? What is the immobiliser LED doing? Have you tried to clear any codes? Do they all come back?
Let me know and I'll reply as soon as I can.
yes the immobiliser LED is the flashing padlock which means this is a later Fiesta. Can you confirm the light flashes with the ignition off, then when you turn the ignition on the LED stays on for three seconds then goes out, is this correct?
Has any work been carried out on the car or was it recovered in?
Let me know,
Hello again, yes I did get the DTC list, U2510 is the code I'm interested in at the moment. Just one more question, does the fuel pump work when you first turn the ignition on? It should pulse for 1 second when you each time you turn the ignition on.
Hello again, you should be able to hear the pump buzz at ignition on and you may also hear the relay behind the glove box click on and off after the 1 second burst.
U2510 would stop the car from starting, this code is for a communication issue between the engine management module (PCM) and the instrument cluster. The instrument cluster is part of the immobiliser on this model, if the instrument cluster can't communicate with the PCM then the immobiliser will remain active. The only thing that concerns me on your car is the fact that the immobiliser LED doesn't flash fast when the ignition is on as it should with this fault. Neither knock sensor code should prevent the car starting and the fuel level sensor code certainly won't.
I would put the most likely cause of the fault as a faulty instrument cluster which would explain why the immobiliser LED is acting as it should.
To confirm this would mean checking the CAN wiring between the cluster and PCM, pins 31 and 32 of the cluster are the can wires, pins F31 and F19 are the CAN wires at the PCM.
To access the PCM wiring means removing the security bolt, when you disconnect the PCM check that there's no corrosion in the connector, also check the engine bay wiring near the gearbox to make sure there is no damage to it causing interference on the CAN.
The knock sensor wiring goes to M16, M31 and M32 of the PCM connector so when the connector is off I would eliminate any wiring concern to the knock sensor.
Let me know if I can assist any further with this or if you need clarification of any point.
Hello again, to check the CAN signal requires a scope, you can check with a voltmeter but these will only give an average voltage which should normally be between zero and 4 volts, it certainly won't read 12 volts. With regard to the knock sensor then a continuity check is OK for this. The terminal pins are numbered in the connectors but if you can't find these let me now and I'll assist further.