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Discussion Starter #1
Hello everyone!
New member here and my fiance just bought an 07 LS 198k miles, and as we got it on the road theres something really weird.
About 3 days ago, when she came home from work around 3am, the engine wouldn't shut off when the key was turned off, and continued to run perfectly smooth. I had to pull the Fuel pump relay to kill the engine AND the Ignition B fuse to release the key. To test, It immediately started up and shut off 3 times after doing so with no problems.
Yesterday I went to AZ to get an ignition switch to start there and it had no problems at all after 4 times turning it off at different stops. Again this morning when my fiance came home again it wouldn't shut off yet again. Pulled relays to kill and replaced to test, but it did it again. BUT this time I noticed the lights were on, on High beams, so on I turned the lights off completely and it shut off 100%. Turned the lights back on and it shut off, but I remembered the high beams were on when she pulled in so I switched to high beams and tried and it would NOT shut down again. Switched to Low and it shut off as normal.
SO, I've got it down to IF the high beams are on the key won't turn the car off, but fine if the low beams are on???
Should I still stick with the ignition switch as I haven't tried to FIRST pull the ignition fuse to see if its that before pulling the fuel pump, but mind you this ONLY happens when the high beams are left on? Or replace the light switch module?
Obviously I get, turn off the high beams stupid, but I'd like to fix whatever is going on and cannot find anything about this strange happening on the net, here, or a Haynes Manuel. Other than the ignition switch would it even BE the light switch, or is the light switch tied into the ignition somehow?
Any help would be greatly appreciated or if anyone has heard of this craziness. I'm going to replace the Ig switch and see what happens but wanted to see if anyone had any insight as well. TIA and stay safe out there!!
FujiMan
 

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Any aftermarket electronics like radios installed? Owners doing these installs themselves make all manner of mistakes and just might have something crossed up between the high beam headlights circuit and an ignition circuit.

Outside of someone accidentally connecting those circuits there is still the possibility of those 2 circuits getting shorted to each other somewhere due to degraded wiring.
 

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Discussion Starter #3
Thanks for replying. I'm about to change the ignition switch but I would like to update that, it must have been pure coincidence but the High beams had nothing to do with it. Meaning She took the car out again this morning and thought to try the "Use only low beams the whole trip" and it still didn't cut off. I then realized I never tried to restart and turn it off after turning the High Beams off one time. So I actually cycled through, on then off, 6 times for each low and high beams. It turned off 4 times and stayed running twice on low, all randomly. Then 5 off 1 on for high beams, randomly again.
Also, to your question, everything is stock and only anomaly that I noticed which is for another time, is in the Fuse box, the last row where the 3 Green 10A fuses are for the 2 ignition and the Blower, is missing the Blower. So I'm wondering if there was an earlier ignition problem that blew a fuse and the previous owner just swapped the blower fuse to use it for the time being. Of IF, the blower is another issue ill have to look into down the road, haha.
Thanks again!
 

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Wow - you didn't accidentally spill some water on a witch, did you?

In days earlier, we had this problem when the diode on the AC compressor was missing or broken open .... and ... YES ... there are diodes on our more modern fuse panels for this same reason - to prevent electrical feedback to a circuit that may keep the engine running IF it stays energized. See? Diodes are used to stop that ... mostly.

First - all problems are caused and it's your job to un-cause it. Make sure that all fuses and relays - where they are actually needed and have the appropriate female spade connex inside the socket - are there.

If you find something that won't hold a fuse (it blows constantly every time you plug it in - or nearly so) - you have to go there and fix that first.

Here's a strange new territory (mental-wise anyway) policy for us to understand - these cars (the ECM, BCM, TCM, and other _CM thingys) don't all go to sleep at the same time ... and certainly not when you merely decide to turn off the key.

There are a lot of things these newer computers do in stages and you can see that happening if you could actually get an Amp-probe onto the battery and watch the current draw slowly blink out in the end of maybe 10-15 minutes.
I'm saying here that a missing relay (or diode) MAY be part of that system shut-down and if one is missing --- well --- who knows at this point what is actually going on.​
Any time someone else has been 'there' I am suspect! You need to be too and don't dismiss inopportune things that may keep you from repair success.
 

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Discussion Starter #5
Wow - you didn't accidentally spill some water on a witch, did you?

In days earlier, we had this problem when the diode on the AC compressor was missing or broken open .... and ... YES ... there are diodes on our more modern fuse panels for this same reason - to prevent electrical feedback to a circuit that may keep the engine running IF it stays energized. See? Diodes are used to stop that ... mostly.

First - all problems are caused and it's your job to un-cause it. Make sure that all fuses and relays - where they are actually needed and have the appropriate female spade connex inside the socket - are there.

If you find something that won't hold a fuse (it blows constantly every time you plug it in - or nearly so) - you have to go there and fix that first.

Here's a strange new territory (mental-wise anyway) policy for us to understand - these cars (the ECM, BCM, TCM, and other _CM thingys) don't all go to sleep at the same time ... and certainly not when you merely decide to turn off the key.

There are a lot of things these newer computers do in stages and you can see that happening if you could actually get an Amp-probe onto the battery and watch the current draw slowly blink out in the end of maybe 10-15 minutes.
I'm saying here that a missing relay (or diode) MAY be part of that system shut-down and if one is missing --- well --- who knows at this point what is actually going on.​
Any time someone else has been 'there' I am suspect! You need to be too and don't dismiss inopportune things that may keep you from repair success.
Thank you for the reply, and at this point I would welcome a Witch to get rid of any Voodooism the 2 Meth heads (they 100% looked the part) that I bought the truck from may have left.
I'm approaching 50 so although auto electrical is long forgotten, I do recall plenty of diodes, "playing with rhe fuse box" to get crap to work by bypassing whatever. Using Gum wrappers in a pinch, and who needs hard wiring when you can just wrap a wire around a fuse peg?!?! LOL.

ANYWAY, I did get it down to "it only happens at night" as during the day the truck starts and turns off perfectly fine 2 dozen times no issues.
SO, I'm guessing I need to find where the sensor that recognizes darkness is and see what I can figure out. Or anyone got a suggestion? Change the Light switch module completely?
I did notice this morning at 5:15 as I turned the key back, it stayed on as before, but if I took my foot off the brake, the Emergency Brake dash light came on with bells and whistles. This happens as I can feel the shifter neutral switch cut off and on as I depress the brake. So at least that part, Park switch or whatever its called now, works!

Also, as we have only just acquired the car, are the daytime running lights suppose to be able go turn off when you turn the switch to the left? As this doesn't so I'm not 100% if that's normal or something ELSE, wrong.
And for anyone that feels the need to troll on my not knowing of something you may feel is common knowledge, please spare any comments. Were all friends here, no need to criticize unless you laugh WITH me and not at me.
And last, if I can post it, anyone have ANY thoughts on why the previous owner would have jumped the low bean fuse to the Fan control fuse? I will say one of the pulleys is making LOTS of noise and its NOT the Alt, PS, tensioner, or the one under the Alt Pulley as I have replaced them. From where its coming from I was guessing the AC pulley and have bought a bypass belt to see if thats it. But guess I need to check the fan now as maybe it was blowing fuses and that's the reason for the jump.
And on TOP of that, could that jump be causing the lights not allowing the car to turn off?
Hahahaha, what the F^¥K did we get ourselves into!!! Hahaha.

Thanks again all for reading my short story and stay safe out there!
Big Fujiman
 

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I'm guessing I need to find where the sensor that recognizes darkness is and see what I can figure out
HIGHLY unlikely the light sensor has something to do with this. Fairly sure the BCM and HVAC use these sensors to control functions like the daylight running lights and as input for solar load for the hvac. The 12 volts needed to keep the engine running doesn't go through these sensors. But just for informational purposes the senors are in that little dome in the dashboard center right up near the windshield and there are 3 parameters monitored from there, left solar liad, right solar load, and light level.
 

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I had to pull the Fuel pump relay to kill the engine AND the Ignition B fuse to release the key.
Re-reading this just now and noted this.... The key cylinder was in the off position but the key would not come out? I didn't know that could happen. I do know the cylinder can't be turned to the off position without battery power present though. Can you clarify that? Was the key not turning to OFF, ir turning and not coming out?
 

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anyone have ANY thoughts on why the previous owner would have jumped the low bean fuse to the Fan control fuse?
Clarification needed. Fuse? Or Relay? Rectangular black or grey box is a relay/module. AND the 2 that are side by side, #45 and #46 I think, are the Fan control and low beam solid state modules. Almost everyone calls them relays but they are not the same as those other similar looking relays in there.
 

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Ok here's "someone else's problem" that I have to play detective on.
This is truly bizzare.

This jumper goes from the RIGHT low beam headlight fuse (which runs at about 80% PWM duty cycle in daylight) to the FAN fuse (hot in run or start).

The end result of this would be during the daytime operation the low beams would be at 100% instead of the reduced power it was designed for.

I would remove that wire and test for the proper power availability to these 2 fuses just to see why someone would do such a thing. Maybe the fan fuse power supply is dead and they just jumped power from another source to get the fan to operate?
 

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TJ .... won't he need a lab scope to backprobe to get a percentile on the PWM for the DDLs? I don't remember seeing a PID for that parameter.
 

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TJ .... won't he need a lab scope to backprobe to get a percentile on the PWM for the DDLs? I don't remember seeing a PID for that parameter.

I didn't mean to suggest that the PWM signal be tested. I was questioning the power to the fuse that is upstream of the fan PWM module. I was looking for a reason someone would run a jumper wire like that. The only possibility I could think of was a failure of the power to the fuse upstream of the fan module. Conceivably someone could have just been looking for a quick way to get power to that fan pwm module and the headlight was where they got power from?

Now if you WERE interested in a PID for the DRL PWM percentage.... I got that! Last year I published a bunch of previously undocumented PIDs over here...


I don't think I have the DRL PID up there though. I have been a little lax in updating that thread. Also just because the PID returns a given percentage one cannot assume the relay/module is actually supplying the proper signal. But you knew that already!

;)
 

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Fujiman, have you checked the engine fan? It has a "hybrid controlled" fan clutch that has been known to give these vehicles different crazy issues. These fan clutches are both electrically AND hydraulically operated. It (or your water pump that it's hooked to) might be your noisy pulley. Mine has a noisy rattle that my friendly mechanic believes is my power steering pump, but it shuts up whenever the A/C is not running. I haven't yet dug into the issue, but will be within the next week or two. I hope you get this issue figured out!
 
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