Inquiring for a friend. Her 2003 Trailblazer has died right in the middle of the road while driving a couple of times. All the gauges go up and down, and the dash lights illuminate. Her mechanic says the battery is fine and cleaned the battery cables but can’t find anything wrong otherwise. He says the alternator is OK. Is this likely connected to an intermittent problems with the battery, a bad ground somewhere, perhaps a crankshaft position sensor, or etc? Any ideas appreciated. I’m trying to point her in the right direction via phone calls.
Yes, who knows? Or fuel pump. I’d just replace the crank sensor as a guess and check fuel pressure. Pumps can come and go but so can other stuff.
Did it restart? Or is it dead right now? Dead now is an exercise in diagnostics. Spark, fuel, compression.
Restarted is a different story. If it set no codes, I’d be looking at electrical connections and a crank sensor for the problem.
Based on the few GM cars we have had in the family,if the battery terminal connections have been cleaned and tightened, I would go to the other end of the ground (black) cable and remove,clean and tighten it.
It will normally start and run with no problem but will sometimes die while she is driving. From her account, it will then restart with no problem.
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Bad ignition switch?
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A failing crankshaft position sensor will act like this. Gets hot, stops working, cools down, starts right up. I’d replace this cheap sensor just to eliminate the possibility.
But I’d still check all the battery and alternator wiring.
I notice you did not mention if any codes were set.
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Didn’t GM recall a bunch of late 90’s early 2000’s vehicles for a faulty ignition switch, just for that reason ?
Not sure if the Trailblazer was one of them.
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It wasn’t, but–of course–this doesn’t mean that the OP’s vehicle doesn’t have a bad ignition switch. IIRC, that recall applied only to the Chevy Cobalt and the mechanically-identical Pontiac version of the Cobalt.
There’s a lot of potential reasons for the engine to stall while driving. In my own experience over the years, the causes were
- faulty fuel pump relay (pump ok, but electrical power was intermittent, worse when hot)
- faulty ignition coil, worse w/ damp weather, puddles on road, more applicable if distributor configured
- faulty ignition module, another symptom for this is cranks but won’t start.
If I had that problem myself I’d rig up a lab volt meter to monitor the ignition system power supply and the fuel pump power supply as I drove. For this particular problem I’m guessing either a fuel pump problem or wiring problem affecting the car’s electrical power supply distribution.