Hello everyone,

I was going through some water this evening and the truck died right near the end. Im sure water splashed under the hood and the water was maybe only 2 feet deep at the worst which I had been through. There is a loud clicking from passenger side dash, the truck wont turn over for the first few seconds then starts to turn over. I have researched the alarm ecu and see that it can cause these issues. I have tried the reset switch for inertia switch. The doors do respond to key fob and key and lights flash accordingly but I cant take the key out of the ignition unless I disconnect the battery. I tried locking and unlocking to no avail as soon as the key is in the run position that box starts ticking. Any tricks or just get another one? Do they need programming? Thank You!

 

Your engine ECU is in a plastic box on passenger side fenderwall, between jug of washer fluid and the battery. Disconnect battery, unplug alarm switch, and remove unit so it will dry out. Only when dry and tested seal with RTV, and use dielectric grease on the electrical connectors.

 

The ECU connections are dry.

 

Moving forward from that is a smaller box, the multifunction relay. Controls lots of things. Also sounds like starter itself has issues, like the solenoid got full of water and does not make a good connection when engaged, finally makes a connection and turns over slowly from high resistance, etc.

 

Starter turns over great, and MFU that controls anything timed has been replaced a while back! All its functions work. Check engine light does not come on and clicking under passenger dash. Has anyone had experience replacing the Alarm ECU? Also if it was immobilized it would not crank correct?

 

What about a wet XYZ switch. Does it think its in gear- preventing the engine from cranking?

 

There is no XYZ switch on a DI, it is a mechanical transmission.

Its your crank position sensor, no check engine light is the clue.
The MIL will not light unless the ECU gets a signal from the crank sensor.

How fast were you driving in this water?

 

And if the starter is operating, then immobilization from the spider is not engaged. But while an XYZ switch is not present, a transfer case position switch is there. It may have gotten wet.

From RAVE:

If the key is in the ignition and the transfer box is in
the neutral position, Interlock Relay 1 (K153) is
de–energised since the relay coil is not grounded by
the Transfer Box Position Switch (X175). When the
relay is de–energised, voltage is applied to the Key
Barrel Switch (X230) through the relay’s switch
contacts and the Key–In Switch (X229) causing the

solenoid to energise and prevent key removal.

 

Its not the transfer case being in neutral, it will still start with the t-case in neutral.

 

I was thinking this might be part of the key removal issue. The delayed crank sounds like a wet connection "burning thru" and finally making conection. ECU circuit board does not like water. MAF sensor connecto does not like water, etc. Hard to trace without a meter or test light.