M48 Open Injector Error

[Cristian G]

Hi guys,

I noticed on the weekend during engine start up and warming up the engine that when we revved the engine I kept getting a "OPEN" error on Injector #3 and #4.

If I let the engine idle itself away 50% of the time the error would clear and the other it stayed and had to be manually cleared through the diagnostics screen.

Is this a normal error? What could be causing it? Should I worry about it?
All other readings/operations were fine and I didn't notice any out of the ordinary readings.

Thanks in advance

Cristian

[Cristian G]

Common guys...

Can't anyone shed some light on this?

Cristian.

[RossB]

This is an injector open circuit error and is not normal. It means that the injector drivers have not reached the current level expected to open the injectors. It could be caused if the Injector Current setting in the ECU is not correct for the injector. Assuming that this setting is correct then it is likely that there is a wiring problem with the injector circuit. I would start by checking the power supply to the injectors.

[Cristian G]

Thanks Ross,

That means I now have lots of fun with a modified wiring loom and a multimeter....

I will check the settings in the ECU as well though.

Regards

Cristian

[RossB]

I don't know how modified your wiring is but from memory there is a connector on the side of the E30 fuse box which connects to the engine loom, the power for the injectors goes through this connector (Blue and white wire I think). I can remember having problems with failures at this connector, the ECU is powered by the same relay but on a seperate circuit.

[Cristian G]

I don't know how modified your wiring is but from memory there is a connector on the side of the E30 fuse box which connects to the engine loom, the power for the injectors goes through this connector (Blue and white wire I think). I can remember having problems with failures at this connector, the ECU is powered by the same relay but on a seperate circuit.

Ross,
Thanks for your help. Unfortunately the wiring on the car only has the same colors as the road car. The entire loom has been rerouted to suit the 1987 BMW Motorsport Group A standards.
In our favor is that the engine loom pretty much runs direct from the ECU to the engine components and there are only 2 or 3 connections to the rest of the car looms. there is no fusebox as the main circuits have been replaced with circuit breakers for ignition, fuel pumps (2 of) and lights only.

At least I know where the injector wires run and I have drawn up a wiring map for this car for teh engine loom already.

Thanks for yoru help, I really appreciate it.

Regards

Cristian