Introduction and unusual non-start problem

[Rickyk]

Hi all.

I've purchased a 740il last week after looking for one for a long time for the right spec. However, the car is a non-runner/project.

The car I have has an usual non-start problem:

If I remove fuse 27, the car will start and cut out immediately however, I have no display.

If I put fuse 27 back in, the car will not crank at all but I will have a display.

I can hear the fuel pump priming however, there is a short "groan" when the key is turned two clicks.

Thanks in advance

Engine is a M62B44TU

Trying to work out how to post pics

Ricky

[Mayorchuck]

That is odd. Fuse 27 does supply power for the MID but should have no tie to starting the car. Fuse 27 does get power from Fuse 110, which is under the passenger seat, or perhaps drivers seat in the UK. We see many issues with water getting under the seats due to sunroof drain issues. That fuse also supplies the power for the OBD II port inside the cabin. On the US cars, the port is located next to the broken cup holder under the HVAC controls. So, Fuse 110 and the solder joint for Fuse 27 are both under the seat. That may be were your problem lies.



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[Elver]

Is it possible that with the fuse in, the car is waiting for a code to start? Check the fuses under seat. Check for proper voltage on all fuses underneath and in the trunk.

[Rickyk]

Hi all

Thanks for your replies.

I've had the carpet up on the drivers side (UK car) and that area is dry and looks as it has never got wet in the past either.

I bridged a wire from under the drivers footwell to the OBD port (it's above the accelerator/gas pedal in UK cars) to get it to work and got the three error codes as EML light is on:

P0123 - TPS/Pedal Position Sensor A Circuit High Input
P0223 - TPS/Pedal Position Sensor/Switch Circuit High Input
P0120 - TPS/Pedal Position Sensor A Circuit Malfunction

A Google search points to a faulty pedal which I will need to replace. When I did a search of the part number, they refer to a pedal for a E53 X5 3.0l and 4.4 V8 - I guess they are not all the same?

I have since pulled out the throttle body cable and cleaned the connector, changed the throttle body from another car as I thought mine was faulty due to a loud clunk when turning the key. I have also cleaned the connector that is plugged into the thermostat housing. Since then, the car will now crank with fuse 27 in and it will try to keep cranking/struggle to start for a few seconds. Engine Failsafe Prog. now appears since changing the throttle body which would mean that I have a faulty throttle body as I did not have this message with the old one.

Correct me if I am wrong but I do not think it is an immobilizer problem otherwise the car will not turnover? - I do not think the accelerator pedal will stop the car from starting either?

I have checked the battery and it was fully charged. I tried jump starting the car too but still the same issue.

Here is a link to the video of my problem so far:

https://youtube.com/shorts/Ye57cJvIj1o?feature=share

[markcrew]

had same problem changed crank and cam sensor dme getting wrong information from sensor no codes came up. alternator problem in the end

[Rickyk]

Thanks Markcrew - I managed to solve it - Replacement DME, EWS and keys.