Thread: TD5 won't start

Originally Posted by DaveP

Hey guys,
I may have got a bit of water inside my TD5 auto the other week.
I bit off a little more than I could chew on a particular water crossing. Anyway, long story short, I ended up with my door speakers all underwater, and my gearbox breather turned out to be hanging down a bit. I managed to get most of the way home before I lost all drive. I got towed home, drained and flushed out the gearbox, and it seemed to be OK. The issue came up that I would take the key out and the ignition would stay on and sometimes the engine would keep running. Anyway, that turned out to be the transmission controller under the passenger seat was submerged in the crossing, which I fixed with another module, which is all good. Now though the car won't even crank over. I turn the key and the relay clicks but it won't crank. I've removed the starter motor and it works fine, I've turned the engine over by hand and that moves fine, I plugged in the Snapon scanner and I got a couple of XYZ switch related faults. I removed the switch, dismantled and cleaned it all out and moved the A/C drain over a bit. I still have no display on the dash as to which gear it's in and my gear selector doesn't light up, so I'm pretty sure that's the issue. Not sure what else could cause it.
The only suspect I have is that the module I bought off ebay was for a P38 range rover but the part numbers all matched up.

Any advice would be fantastic.
Cheers, Dave.

The Transmission ECU on a TD5 is a different part number to the one on a V8:
TD5 (EU3 engine 2002 onwards) uses a LR IGG00070 earlier models used a UHC100250 then IGG100010 superceeded by IGG000060. A Discovery 2 V8 4.0L High compression uses a LR UHC100260 superceeded by IGG100020 superceeded by IGG000010 which was then superceeded by IGG000040 in 2000. The low compression V8 uses different part numbers again.
I have heard of a v8 ECU working with a TD5 but don't know which part numbers worked and how well.

What part number ECU are you using ?
What is your VIN number? eg YA, 1A, 2A etc ?

Dave,
where about's in Perth are you?


I have a spare TD5 trans ecu you can try if you want, its for an early model (pre face lift)


Roger

Hi, first of all check fuse F23 interior fusebox, if it's good are you sure the starter relay is what you hear clicking?, cos there are other relays too which would work on ignition crank position... that's important cos your problem can be from the BCU too, this one controlls the earth to the starter relay coil, the indication on the LCD and the illumination of gear position... make sure that's no water ingress at the BCU too(it's behind the glovebox)

i dunno how that snap-on tool works but dont you have some kind of "circuit test" capability to see if the XYZ switch gives the outputs to the transmission ECU or not, usually when the problem is from the transmission management area the M + S lights are flashing... did you clear those fault codes and read again? cos they might have been hystorical

remove the starter relay(R2) and check with a multimeter if you get earth with ignition to crank where terminal 86 of the relay must be(there's a scheme on the relay's body)...if no earth there IMO the problem is from the BCU

Thanks for the replies guys,
Gazk, I'll attach photo's of the new and old TCU's.
My VIN is SALLTGM931A710668.
New:

Old:


Disco WA, I'm in High Wycombe.. I'd really appreciate that if it's not too much trouble.

Sierrafery, I've checked that fuse, it's OK, there's no water ingress anywhere under the dash, and I've tried the earths, there's no earth at 86 at all, only at pin 30 of the starter relay.

Cheers.

Originally Posted by DaveP

Thanks for the replies guys,
Gazk, I'll attach photo's of the new and old TCU's.
My VIN is SALLTGM931A710668.
New:

Old:

The UHC100250 was used on TD5s up to VIN XA232916 (1999)
The IGG100010 was used on TD5s from VIN XA232917 onwards and the Microcat parts catalog shows this is correct for your VIN and that IGG100010 was later superceeded by IGG000060.

Originally Posted by DaveP

Sierrafery, I've checked that fuse, it's OK, there's no water ingress anywhere under the dash, and I've tried the earths,
1. there's no earth at 86 at all,

2. only at pin 30 of the starter relay.

Cheers.

1. then one of your problems is that the BCU doesnt switch the earth to the starter relay's coil that's why it doesnt close when you crank, also as i said the LCD and the gear position display is managed by the BCU too.

2. didnt you mix things there cos to pin 30 comes direct live from FL12

check the starting and charging diagram in RAVE and the BCU description and operation cos imo there's some problem