M35 Gremlins In Electrical

[Equilibrise]

Well, she's once again off the road. Here's what happened:

Last week i noticed that the starter motor was struggling at random times but still managed to get the engine going. Next it seemed like there wasn't enough juice in the battery to start it and had to get a jump and let it run for a long time to recharge the battery. I then filled up with fuel and again had to get a jump, except it took around 7 attempts to get it started.

Once I got home i was able to put the multi meter on the terminals as i suspected either the battery or alternator. Alternator was charging at 13.5v (a little low) and after sitting for a while, the battery was at 11v. I was then able to jump start the car with a lithium ion 600amp battery booster every time for the following day.

Next, the engine would crank with the battery booster, but not start, the stock radio said TRAFFIC, and the a/c switched itself on. I checked all fuses in the 3 fuse boxes and all were good. I checked for ecu error codes manually which came up clear. I then found that the fuel pump (which is hard wired via relay) was not receiving signal to switch on. I then bypassed the relay so that the pump runs continuously and was able to start the car and get it home.

I then assumed that it is a problem with the IPDM (secret fuse/distribution box behind battery), so i removed, dismantled, inspected and cleaned it with contact cleaner. After installing it and soughting out fuel pump wiring back to how it should be, the next start attempt cranked the engine very slowly and i noticed that the battery booster was flat.

After it was recharged, i unlocked the car and the fog lights and a/c came on without any physical switches being in the on position. Once i attached the battery booster the fog lights swiched off. Now when attempting to start the engine doesn't crank at all and the gear selector display on the dash is blank. All other dash lights work, fuses are ok, no error codes with scanner, fuel pump is switching on and battery is at 10.5v disconnected from booster.

Now i'm starting to think its got to do with the immobiliser, so i completely remove it from the car. Hooray! The car now starts as normal and alternator is charging battery at 14.3v (optimum!)

I switched the car off, tidied up the mess i made of the trim and cables and put the booster back on charge. Then when i unlocked the car it attempted to run the windscreen wipers without any switch telling it to do so. I tried to start it and it is back to not cranking at all with all the dash lights working, no error codes and no gear display on the dash.

At this point I'm finding hard to link all this weirdness together so i welcome everyone's pov. I'm down to thinking its either BCM, IPDM, battery or starter is so bad its reversing voltage at times.

FYI, the starter was rebuilt 8 months ago and the battery is 18-24 months old and the car is in a position where a tow truck can not access to take to a repairer, so i have to work it out (with your help).

[Equilibrise]

Also, the immobiliser is still out of the car and i have disconnected all aftermarket electronic goodies.

Any input is greatly appreciated.

[scotty nm35]

Have you popped the bung out of the battery compartment yet? Could be filling with water, it's pretty common for electrical gremlins once the IPDM gets moisture in it.

[Jetwreck]

Head on over and I'll put in on one of my Snap on Scanners

[Equilibrise]

Thanks Scotty, i removed the bung a long time ago. There was evidence of previous moisture damage to the IPDM on the inside of it, but nothing was wet when i dismantled it.

Thanks Craig, i am actually working around the corner from your place atm. Unfortunately, however, the car is not starting at all so i can't get it to you.

[Equilibrise]

Anyone know if the IPDM is interchangeable? Someone said that it is paired with the ecu.

[conan7772]

What about the ECU itself ?

Is there a test / scan for the ecu ?

Maybe getting moisture down onto it.

My alarm plays up when it rains..

[scotty nm35]

The IPDM isn't Vin coded or anything Alex, but it could be vehicle specific. As long as the part numbers are the same you will be ok, but the V35 IPDM is definitely different. Glad it isn't like the Audi's.

[BoostdR]

Sounds like the ignition signal from the tumbler to starter motor is low(resistance in the cct). Had the same issue with a C34. Trace the cct. It's a low current wire(small)

Edited February 2, 2016 by BoostdR

[conan7772]

The IPDM isn't Vin coded or anything Alex, but it could be vehicle specific. As long as the part numbers are the same you will be ok, but the V35 IPDM is definitely different. Glad it isn't like the Audi's.

I wasn't talking about compatibility or the IPDM.

Just the possibility the main ECU has died.

[Equilibrise]

The m35 master, scotty was right.

The problems were all caused by the IPDM (Intellegent Power Distribution Module). Shame its located in an unintelligent location!

Although the unit was not wet, it had signs of being wet some time in its life in the form of corrosion which looked minor, except it wasn't.

FYI nissan want $1050 for a new one with no fuses or relays included!

I replaced mine with another from a wrecker. It was from a newer model m35 than mine. The only physical difference i found between them is a single different relay (seems to have an inbuilt resistor) and no corrosion.

Car has been operating well for a week so far.

Thanks all for your input!

[Daleo]

Great result; nice work on actually posting you solution too!

[scotty nm35]

The m35 master, scotty was right.

The problems were all caused by the IPDM (Intellegent Power Distribution Module). Shame its located in an unintelligent location!

Although the unit was not wet, it had signs of being wet some time in its life in the form of corrosion which looked minor, except it wasn't.

FYI nissan want $1050 for a new one with no fuses or relays included!

I replaced mine with another from a wrecker. It was from a newer model m35 than mine. The only physical difference i found between them is a single different relay (seems to have an inbuilt resistor) and no corrosion.

Car has been operating well for a week so far.

Thanks all for your input!

Nice one Adam, did you pop the bung out to stop the water building up?