HELP!! I've got a 98/99 D2 4.0 Thor V8. Car was running sweet, parked it up before New year's eve and went back out on Jan 2nd, it cranks but won't start. Rev counter doesn't move while cranking. I'musually pretty hands on but I've been recovering from cancer surgery so it took a back seat. I've since replaced the CPS, coil packs, plugs/HT leads/fuel pump. It's got no power to the fuel pump. Error code P1231 on Nanocom. Driver's window and driver's electric seat no longer works back/forwards, screenwash no longer squirts. Can anyone help at all, or provide advice. The wife wants to scrap the car!! This particular car has had the alarm and EKA disabled by previous owner.

I have been given a matching BCU, ECU and Key Fob Circuit Board from a 2002/2003 breaker. We know they all work, it had chassis rot, is it possible to swap those over into my car and see if the car starts? Plug and play and relearn security code via Nanocom?
I tried the relearn security code on the existing BCU via Nanocom, it Cranks, oil light goes out but check engine light appears, rev counter doesn't move when cranking over, no fuel pump priming on pos II ignition. Thanks Craig.

 

Good idea to post the description for the P1231, doubtful many of us have memorized that. Start with easy stuff and then get more methodical. Check to see if the fuel pump relay is being energized when the key is first turned on and/or while cranking. You said no fuel pump priming, so we need to determine why. If no signal at relay, it is an ecu/security issue. Lock and unlock the car three times - observe the red security light on the dash. You can rent the Nanocom at extinctmotorsports.com if the lock/unlock does not work but I have never had to do that. If you have the full set of replacement ECU's why not give them a try? All you need to do is put them in and turn the key on for 20 mins for the ecu in the interior fusebox to sync with the BCU and the car should start.

 

P1231 - Fuel pump/relay drive cycle - signal missing. This is what appears on my Nanocom.
The relay energises off and on with the ignition. But no pump prime.
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If the relay is energizing but the pump is not coming on you may have a bad pump. Jumper the relay slots and see if it runs.

 

Pump works with direct 12V applied from car battery. Will try the slots.

 

It's also a new pump.

 

Did you press the inertia switch? I think that will allow cranking but cuts power to the fuel pump.

 

Yes, pressed it and also swapped it out for a new one.

 

Ok, so pump runs with power at the pump, but does not run when relay is energized? Did you jumper the slots? If it runs with power at the pump but does not with the relay energized or the slots jumped you have a wiring issue between the pump and the fusebox.

 

Will try and jumper the slots tonight, could it be a BCU fault?