1996 E38 740i Not Starting

Hello All, This is my initial newcomer posting on Bimmerfest copied & pasted to the 7 forum.

To start I was a Very Happy driver of a 1996 manufactured E38 740i residing in the Johannesburg area of South Africa. I am working in Ghana & keep this car for when I come home on leave four times a year. Unfortunately due to not being able to start my car I have not been able to use it this time & have resorted to using a spare 316 although it gets me from A to B it is "Not" in the fashion that I have become accustomed to.

To cut a story short I have landed at Bimmerfest & become a new member due to searching for a solution to fix my not starting problem. Big

The symptoms are that the starter does not engage & there are no gear selection lights illuminating. Only the "S" illuminates when the Sport Position is selected. The Starter turns the engine when the Solenoid is energized but does not start.

To reflect on the onslaught of the problem my son was driving this car when he says that it suddenly died on him.

I have read plenty of the posted remedies given to guys who have cars with similar problems & have established that there is "No Power" being delivered to the Transmission Position Switch.

I have a reasonable understanding of basic systems & circuits & have checked all of the simplicities being fuses & relays.

I have been searching endlessly for a source where I can download Electrical Schematics but the best I have come up with is a complete Manual which is very poorly copied into PDF format which has split pages which ironically are the ones I require. The other schematics I downloaded are perfect but are for a 95 model with a M60 4.0litre engine. I have bought CDs on eBay in the UK but most of these guys do not post directly to us especially in Africa. My daughter has posted them on but this doesn't help at present, not only that the cost of searching & downloading is mounting up. I have not been able to locate a download, only CDs & Hard Copies.

I am at present downloading the 7 Series Manual from eMANUAL

Correct drawings for my particular model will be greatly appreciated which will allow me to trace where the dead wires should get their power from, & of course send to.

I would be grateful to anybody who can throw some light on my predicament,

Cheers Clive.

Please carry out a fault code test as this should tell you what is wrong with your BMW

Like stated above, scan the car for codes, using a code reader if available. If the batt was not disconnected or drained you might have a transmission code stored and this could be a clue in your diagnosis.

Indeed the NO start situation is due to your gear selector switch not getting power or is at fault. I don't have the diagram handy, to get them I would go to a BMW dealership if available, try to get them from there, order a service manual from dealership or use ALLDATA.com (pay the membership), or look for Mitchell auto software on the internet.
Without any diagram I would remove the round jack that goes in the transmission, and using a voltmeter I would check if there is any power coming to the transmission. I would start to check if the battery has enough voltage, if there is any voltage coming to the shifting level switch/solenoid. Since is illuminating only in S mode that is the problem.

Thanks for the reply Joy,

I have put a code reader onto the system which comes up with nothing. I used a D-CAN GT1.INPA reader with compatible BMW software which comes up blank. I have also bought & plugged on a different ECU & TCU with no changes to the readings or light illuminations.

There doesn't seem to be power at Terminal 15 of which I am not sure what this refers to. I have found that the Relay for Terminal 15 is under the Electrical Component ECU & TCU Box in the Engine Compartment. I have swapped out this relay which made no difference.

I will get hold of the relevant schematics in order to find out where the feed comes from to the Transmission Position Switch. The schematic for the 95 model says that the power for the Transmission system comes from Fuse 22. I do have four cables with power going into the TCU.

I will go to ALLDATA.com & see what I can get there to have another go at tracing the wiring today. I will let you know how I get on,

Cheers Clive.

Is the battery ok? Low voltage brings on all manner of strange things.

Low Voltage is a good point, it's surprising how even a slightly low battery that will still start the car will cause all manner of strange problems that don't seem to make sense. Fwiw I had the battery low once and it cranked over rather slowly, but did in fact start. However, the SRS airbag light turned on and transmission went into failsafe mode. Drove for an hour, turned it off and started it again and it acted like nothing happened.

If your car was stored for a while with the battery connected, it may be good to pull the battery for a day or two and have it fully charged, then reinstall and start.

Sent from my Galaxy Tab using BimmerApp

Have you tried to check the error memory of the transmission control module using INPA and it came on nothing? If there's absolutely no error stored, low/no voltage could be the issue.
If you swap the TCU or the ECU without align them with the EWS will not start. EWS= immobilizer module.

Edit: TC module is the first one (from front to rear) in the E box. Shift solenoid is in the transmission and is fed through a bunch of cables (round connector).

The TC module is powered from 2 30A fuses from the ebox. Check these fuses first. Cables from the fuse to TCM are RT & RT/BL. The TCM is also fed from the ECM relay (in the Ebox) cable rt/sw/ge.

The shift solenoid gets power from fuse 22(10A) to pin 5 at the connectorXB532. If you don't get power at this wire check fuse 22. From the shift solenoid to TCM
SW/VI, pin 53 from TC module feeds from neutral/park.

Fuse 22 & fuse 24= Engine control and they are all in the Ebox.

Thanks all, the Battery is good & has been discharge tested at the battery centre. I have also been using a good second battery when the power drops from fault finding.

I have checked all of the fuses for continuity but I will go further & check the power going through the wiring from fuse 22 & the ECM Relay in the morning. From there I will check for power at the round plug wiring to the shift solenoid.

I don't see any mention of BMWs in the ALLDATA Website & the file i downloaded from eMANUALS does not contain Wiring Diagrams. Are there any other options apart from BMW.

Will see what tomorrow brings.

Best way to test the fuses are by removing them and then checking for continuity. If you let them in place and check for continuity you might get fouled.

All cable joints and earths may need a good look too.

Hello Joy & all,

I have checked the fuses externally & they are ok. There is battery voltage on both sides of the fuses with the ignition switched on.

There is only 1.1volts found at terminal 5 of the Round Pinned Plug to the Transmission Solenoid Valve Block in the Transmission. Voltages found at all of the pins are as follows;

Pin 1 = 1.1volts
Pin 2 = 0volts
Pin 3 = 0volts
Pin 4 = 1.21volts
Pin 5 = 1.1volts
Pin 6 = 1.46volts
Pin 7 = 0volts
Pin 8 = 1.22volts
Pin 9 = 1.22volts
Pin 10 = 1.46volts
Pin 11 = 0volts
Pin 12 = 0.8volts
Pin 13 = 4.98volts
Pin 14 = 0volts
Pin 15 = 0volts
Pin 16 = 0.8volts

What voltage should Terminal 5 have?

Can you draw any conclusions from this?

Can you help me with Electrical schematics for this car. The closest I have is for a 95 model & a ZF 5HP-19 Transmission,

Cheers Clive.

Originally Posted by Clive5136

Hello Joy & all,

I have checked the fuses externally & they are ok. There is battery voltage on both sides of the fuses with the ignition switched on.

There is only 1.1volts found at terminal 5 of the Round Pinned Plug to the Transmission Solenoid Valve Block in the Transmission.

Can you draw any conclusions from this?

So you have battery voltage passing the fuse 22 but at pin #5 of the round connector only 1.1V? This means that the wire is damaged somewhere. Does the wire has the same color at fuse 22 and pin #5? If not, it has another connector somewhere on the way to the transmission. Do a visual inspection.