GMC Jimmy no start - shift interlock problem?

I have a 98 Jimmy with a new problem...

The vehicle won't start. I here the fuel pump run when I switch the key to RUN, and the engine cranks when in START, but it won't catch.

A couple of interesting related symptoms:

  1. The shifter is stuck in park (with my foot on the parking brake of course)
  2. The guages are all stuck a 0 (even in the run position).

Do I have multiple problems? Is there a shift interlock cable that also tells the PCM to fire the ignition?

Ideas? Is this a common problem? (I'm hoping not to mess with the steering column since I have an air bag).

Thanks, Mike

Reply to
Mike
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Sounds like the ignition switch.

Reply to
Neil Nelson

I can see the ignition switch being the cause of ignition not firing, but how would this affect the shift interlock?

I think that the crank is on a seperate switched circuit than guages & PCM - that might explain the guages staying off.

Mike

Reply to
Mike

I had something similar with my Envoy (Jimmy Style), turned out to be the ignition coil.

Reply to
David

FIXED IT!

You were right, just the ignition switch. The switch has two seperate circuits, one which cranks the engine, another which powers the PCM (for firing the plugs) and for the guages. One of the circuits didn't work.

It also explains the shift lock problem - it seems that by 1998 GM used solenoids only (no more cables)...thus the open circuit kept the solenoid from pulling in.

I disassembled the ignition switch and cleaned contact, etc. I found one badly arced so I cleaned and adjusted the flex.

Thanks for the help.

Mike

Reply to
Mike

Glad to help Mike.

This is an increasingly common problem.

I'd advise replacing the old switch as soon as possible, I believe the replacements from GM have been upgraded.

Reply to
Neil Nelson

The wires on the ignition switch appear to be welded (and soldered) - and the other end of the wires go to pins in the C100 type connector. Would a new switch come with a wiring harness ending in pins - or would I need to weld the big ignition wires? (In which case I don't have the tools)

Mike

Reply to
Mike

The new switch will come with the connector and terminal pins, no welding, soldering, splicing, crimping etc. needed.

Once you see the new switch, it will become readily obvious how the plug is configured, and considering that you managed to remove, disassemble and clean the old switch, putting in a new one should be fairly easy for you. 8^)

Reply to
Neil Nelson

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