Dead ignition

[Mikie]

Thanks in advance for your help.

This week I took a trip and had a weird starting issue.

• TB starts fine in the morning
• After work I try and start the TB and no go.
• Key fob does not work, ignition does nothing.
• Thinking battery I get a jumo, and no go.
• Guy helping me jumps the starter with a screwdriver and it turns over
• He suggests pulling the negative terminal, ten minutes later reconnect and it starts.
• Starts consistantly over the next hour. Park and leave over night.

Guy says it is the security feature going goofy. Same symptoms if left for more than 4 hours over the next 3 days.

I did notice that the front fuse 13 was blown and replaced.

Put a code scanner on it and nothing shows up. Inconvenient yes, embarrassing to the extreme.

Any ideas?

 

[Matt]

Sounds like an ignition switch may be called for. When they go, all sorts of electrical things go goofy.

 

[MAY03LT]

Key fob does not work, ignition does nothing.

Nothing worked? In that case I would start by checking the condition of the battery terminals.

 

[Mikie]

Battery terminals clean. One thing I forgot to mention all interior lights were not working along with the radio. Dash, odometer, and climate control worked.
Head lights never dimmed when key was turned.

I left it parked overnight last night and it started perfectly. The only change was replacement of the lighter fuse #13.

I know this also controls the OBDC port, does it have any connection to the built in security around the ignition?

 

[Wooluf1952]

Battery terminals clean. One thing I forgot to mention all interior lights were not working along with the radio. Dash, odometer, and climate control worked.
Head lights never dimmed when key was turned.

I left it parked overnight last night and it started perfectly. The only change was replacement of the lighter fuse #13.

I know this also controls the OBDC port, does it have any connection to the built in security around the ignition?

That sounds like the mega-fuse blew.

 

[Mikie]

The only fuse that was blown was the cigar lighter.

After looking at the wiring diagrams and tracing a few things I am beginning to believe that the theft deterrent control module was tripped. Does anybody know exactly what it does when tripped? How does it communicate to the PCM & BCM? It looks like it is sending an actual waveform signal and not just a B+ or ground in the diagrams.

If this happens again, it looks like I can pull front fuse 34 (B+ to layer 1 of the ignition switch) to reset the module without pulling the battery. If that does the trick, next time it happens I will pull fuse #47 in the rear fuse box. If that doesn't work then try fuse #50.