Thread: gearbox question

When I first got my P38, it drove home perfectly.
Can you imagine the look on my face when, the next morning I tried to start it up and got all sorts of error messages popping up, (transfer case overheat, loss of traction, other scary messages including gearbox errors), the car would not turn over properly either.
As I had no experience with P38's, I went to my basic mechanical thinking and removed the battery cover and checked the battery. The terminals were horribly corroded!
I cleaned them up and it would still not run properly.
Put a new battery in and like magic, everything was perfect again.
P38's seem very sensitve to low voltage, the EFI needs a solid battery to work properly.
If your battery is suspect, I would at least get it load tested, I'm thinking if it has sat there unused for a year you may want to put a new battery in anyway for piece of mind.
You know how these things go, right when you need it the most, that's when it fails!

I had exactly the same experience as yourself Peter. It took about a week of regular use for everything to come right with a new battery

Unfortunately the transfer ecu has no electronic diagnostics.

If its not a voltage issue you can unplug the shift motor in high range you can check continuity of the switches that tell the ecu how far to turn the motor. Then do it again in low. From memory there are four switches a-d. If a, c and d show continuity then it may mean left of high, right of high - etc. Thats a pretty dodgy explanation, but it's all in rave. Basically the logic sequence of those four switches tells the ecu where to shift the motor. There's a graph in rave with the logic sequence, and youll neex the etm for the pinout of the plug. ( you dont need the dissconnect the battery)

If the logic sequence checks out good I'd check your getting the same logic signal at the ecu plug. Also have a look inside the ecu, they're known to fail. You'll see some melted componants if it has.

If the logic sequence doesn't check out okay, it'll be within the wiper switches in the motor. They could just be dirty.

My 95 hse was error message crazy till, through this very forum I was educated in the finer art of owning an RRp38. Rule 1 must have good battery Rule 2 Read rule 1.
Good Luck with yours !

Bp38

Thanks for the quick replies, I will look at getting a new battery as a matter of urgency, at least then if that's not the problem I know sooner rather than later.

Maybe duel battery system should go on the to do list as well.

My thoughts are the connections in the selector switch could be dirty. Run the lever back and forth a good few times and also put it into low and do the same. If it does not work the 1st time do it a few more times whenever you get the warning to see if you have any better luck.
As others have commented, Battery must be 100%
Let us know how you go

I had the ' Select neutral ' message too, but gradually got better. Must be the selector, then again since I put the optima yellow top in, I haven't had any issues at all.