I am currently having an issue with my 2003 Yukon XL. Randomly, but mostly associated with hot outside air temps or while pulling our camper the truck will just shut off. Almost like we turned off the ignition. We don’t get any sputtering or misfiring, nor does the CE light come on. After about 3-5 min we can start the truck up and keep on going. On the hot days it may do it a few more times but on others it wont do it again for weeks. I recently had it looked at and the mechanic thought it was a fuel pump. But after finding out the cost of the repair I did some investigating and found other people have had this problem. They to were told it was a fule pump. However after it was replaced they still have had the problem. Does anyone out there have any thoughts?
The problem might be with the crankshaft position sensor being effected by heat. This can be verified by measuring the resistance of the crankshaft sensor and then heat the sensor with a heat gun to see if the sensor resistance reading goes out of spec.
Almost like we turned off the ignition.
Is it truly like turning the key off? If the vehicle stops running, do all the dash lights (like ALT/BATT, OIL lights) come on?
If they go off when the car dies, do things that normally operate without the key having to be in (like the dome light) still work?
My wife is the primary driver of the truck. So it has happened to her the most. She says that it just shuts off, does not remember the dash lights coming on. She says it just shuts off without warning. When i have driven and it occurs i was pulling a camper. At that time i would be on the express way trying to get up to speed or go up a hill and i could sense a loss of engine power. Then it would shut off but i do recall the dash lights coming on.
Just a note…the times it did it for me the CE light would come on. It said i had a bad mass air flow sensor. After replacing the CE light went away and has not come on anymore when this issue happens.
The next time it happens, take note of whether the dome light still comes on when you open the door.
I’m thinking that perhaps your ignition switch or a connection related to it is on its way out because, if you turned the ignition key off while driving, you would also not see the dash lights come on.
If it were something related to the engine, it would stall but your BATT/ALT and OIL light would turn on.
I asked about the dome light because if it happens and the dome light also doesn’t come on, it is more likely to be related to the battery or one of its connections. See, the dome light isn’t tied to your ignition switch. It is supposed to come on whether the switch is in our out.
It helps narrow the problem down.
after a week or so the truck acted up again. This time the truck would not even start after leaving a store. My wife turned the key and only the dash lights came on. Nothing else happened. No clicking or anything. After sveral min. the truck started but after just a few min. of driving it shut off. She said that none of the dash lights came on but the radio and the dome light did work. It would start after a few min but agian shut off after a few miles. It did this about 2 more times before she got home. That was about 4 days ago. It has not done that since.
My 2002 Yukon XL is doing this same thing it will throw no codes and no warning lights. what we have replaced over the last year to try and fix the problem MAPS sensor, Mass air flow sensor, fuel filter, Alternator and Battery NONE of these have fixed the problem. It will start up usually first try after it shuts down but no warning when it shuts off I have been doing 65 mph or 30 mph and just resently while just at an idle.
I had this same issue with my 03 XL. All I can tell you after 4 different dealers, almost being hit by a semi, being stuck on the ramp up the Zilwaukee bridge and stranded with a 1 year old at dusk in the middle of state land - FUEL PUMP. A lot of time was spent researching by multiple parties, but in the end, one persistent dealer ran the car for over 24 hours and with the right temp outside, it finally failed. All other times it failed on my, nothing in the computer.
Tester is usually correct, and I think he’s most likely right this time too: bad crank angle sensor. Replace it.
Same thing just happened to my son in our 2002 Yukon XL Denali. Shut off, would not start, towed to a local shop, 4 hours on the lift with 3 mechanics, started right up but they really don’t know why, or why it failed. Car has 190K on it, usually trouble free. Heat isn’t the issue here, 58 degrees. I’ll ask about the crankshaft position sensor, any other ideas? Thanks all!
Fixed. I had the same issue of stalling. It seemed to happen on left turns at idle. Mechanic said this is a common problem. Something comes lose and causes the wiring that runs down behind the power steering to get snagged. They had to pull it out and splice wires. It’s Fixed!! This is after I cleaned the throttle body and MAF then replaced the CAM sensor, Crank sensor and TPS.