Thread: td5 ecu

Originally Posted by Scottish David

td5 replaced injector pump loom. cleaned oil from coupling to ecu. now have to lock/ unlock car several times to cancel immobiliser, no radio ,no clock, no signal to ebd. any suggestions other than trying another ecu?

I'm reasonably sure that the ECU (Engine Control Unit) is not responsible for these issues. Check the BCU (Body Control Unit) immobiliser and other issues.

Cheers,

Franz

Originally Posted by Scottish David

td5 replaced injector pump loom. cleaned oil from coupling to ecu. now have to lock/ unlock car several times to cancel immobiliser, no radio ,no clock, no signal to ebd. any suggestions other than trying another ecu?

Check and re check all the fuses.
Are your interior lights working? I think these are on the same fuse as immobiliser.

HTH

Dylan

If the clock is not working then it will be a power supply wiring issue. The clock is supplied from the auxiliary circuit relay in the engine compartment fuse box, then a fuse in the passenger compartment fuse box.

The fact this has followed work on the ECU would suggest it is related to the wiring in the immediate vicinity of the ECU.

I'd make the observation that there is no separate device called an "immobiliser" on the D2 Td5, so you'll struggle to find a fuse that powers this. The immobiliser function is performed by BCU and ECM.

To wit:

Immobilisation
For immobilisation, the BCU disables the starter motor relay. When the engine is cranking, the ECM looks for a coded
signal from the BCU. If the signal is not received within one second of cranking, the fuel supply to the engine is
stopped and the injectors are disabled. This also prevents unburnt fuel from entering the catalyst.

If the BCU is disconnected, the engine starter motor will remain isolated by the starter motor relay and the ECM will
remain immobilised. The main wiring for the system is contained within the main harness which is relatively
inaccessible, so preventing intruders from disabling the system by cutting the wires for the immobilisation system.
Once the immobiliser has been activated, destruction of the trigger device or the wiring to it will not disarm the system.

The RF transmitter communicates to the BCU via the RF receiver using a 70 bit code. Pressing the unlock button on
the transmitter will re-mobilise the vehicle. The RF transponder is integrated into the metal key assembly, inserting
the key into the ignition switch will induce a signal in the exciter coil to re-mobilise the vehicle.

There is a module called the IDM located in the passenger compartment fuse box which acts as an interface to the instrument panel and provides relay control for many functions. If this was not getting power you'd have widespread mayhem - instruments warning lights not working for example.

Also curious what "ebd" is? I'm aware of "electronic brakeforce distribution" aspect of the SLABS ecu.

BTW This discussion really should go in a new thread rather than the "welcome to the diagnostic forum" thread.