So, I started having a weird issue on an LR3 I bought.

Previous owner hosed down engine bay and the vehicle went crazy. I bought it and cleaned the Engine ECU and T case ECU up and the connectors. Plugged it back in and cleared all the faults. Presto, all good.

Then after 2 weeks of bliss, I go to start it and get a F on the dash with a trans fault, and about every other fault you can imagine. Also weird is the temp gauge is pegged in red and gas tank says its full when not, plus it won't start.

Then I clear the faults and it starts and is fine. Drives OK for a few days, then repeats the same thing. Now after repeated attempts to start without clearing codes it will start, but has a fault for the trans and does not shift properly. But after restarting trans fault goes away and CEL is on. But after another start then stop cycle it goes away. This repeats every day or 2.

Common denominator for all codes is lost comms with engine PCM(ECU). So I clean connections, test the CAN BUS pins on OBDII connector and conclude that I need a new Engine PCM. $1450 is the cheapest I can find(try to code used ones with no luck). Put a new Engine ECU, drive off with renewed confidence... until it repeats.

Dig in again and find that the vent hose from the battery is going towards behind the fuse box, but ends just there and does not dip down through the rubber connector through the bottom of the firewall. Pretty much vents to the negative battery terminal.

So, I pull the negative terminal and find what looks like some weird corrosion and it is inferior to the Neg cable on an 05' I have(this is an 06').

I put another cable that was superior and have been crossing my fingers every time I start it. I will keep everyone posted including the original COMPUTER NIGHTMARE POSTER.

See pics:

 

Interesting. Halfway through I though to myself: "sounds like a bad ground". Good luck!

 

Yeah, wish I would have dug deeper before buying the ECU. Oh well, lesson learned. Let's see if it holds.

 

Abran, was the new cable oem? The old one looks like someone tried to do a decent job of solder connecting a tip onto the cable... doesn't look original.

 

Both were OEM.

 

The second one you replaced it with must have been an engineering update. Having the cable ends open like that woudl definitely allow for corrosion creep.

 

The strange part is the open end cable was on an 06' and the other an 05'.

i should have looked at the dates on each as they both have their OEM labels on them. I might have thrown the open end cable away.