Security light on after replacing starter.

Chevygirl

Original poster
Member
Jul 10, 2020
1
Phoenix, AZ
Hello I am so stumped right now and ready to pull my hair out. So I have 2003 chevy trailblazer ext that I just bought about 2 months ago. I love trail blazers so much and I couldn't pass up on the ext. She drives amazing that is until one night I was leaving the grocery store and she would not start I had all lights on inside. I tried three times and she finally started. When I got home I turned her off and then turned her back on and she wouldnt start again. Did some research and it was my starter. So we replaced that, then the starter would not turn off it just kept running so we checked wires and fuses and were stumped so I took to a buddy he said it sounded like the ignition so he checked and said it was good. The starter has constant power running to it and can't find where. So we put in a push start. Through all of this the security light flashes and then goes away. The only way I can get her started now is by trying to start her once turn it off bang on the ignition turn key to on bang on ignition push the button and she starts. Please help I am so loosing my mind and just want my baby back. Before the starter went she never had any problems no security light no check engine light she still has no check engine light.
 

TJBaker57

Member
Aug 16, 2015
2,897
Colorado
sorry to be thick headed here....maybe. I need some clarification, and maybe a few commas... maybe.

When you say "bang on" does it mean you literally are hitting the ignition key/lock cylinder/steering column area? If so then this is sounding like a possible issue with the passlock sensor in the ignition cylinder/lock. The reason it doesn't start with the push button may be the security system thinks you are trying to steal her!
 
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gmcman

Member
Dec 12, 2011
4,656
I agree it likely thinks you are trying to "hotwire" the vehicle. The push-start setup MUST be removed

If you turn the key and there is 12V to the solenoid and no start, then very likely it's the starter or solenoid.

When the starter keeps running when you release the key, did the dash lights remain off or did they come back on?

I mean this in a nice way, but when the starter kept running, did you verify there was 12V to the solenoid at that time or assume it had power since it kept running? Very likely you have a faulty starter and the solenoid is sticking, maybe also a bad relay.

Don't discount a faulty ignition switch, especially being a 2003. I would personally replace the ignition switch to be on the safe side anyway AFTER you verify whether or not you have 12V at the SOLENOID with the key released and the starter is continuing to run.

Sounds like you started (no pun) with a bad starter or ignition switch, but now you need to:

1. Remove that push-start and CONFIRM a possible faulty ignition switch (which are NOTOTIOUS) for going bad.

2) Verify voltage at the SMALL solenoid wire when the key is turned, and that the voltage is removed when the key is released. Keep in mind, you may still have voltage at the small solenoid wire a few moments after releasing the key, but not more than a second or 2.
 

Mooseman

Moderator
Dec 4, 2011
25,262
Ottawa, ON
The starter that keeps cranking if you release the key before it starts is normal. The PCM will keep cranking for 3-5 seconds after key release until it starts or fails to start and will automatically stop. If it keeps cranking after it does start, I'd check the starter relay and the ground output to the starter relay from the PCM.

If the security light is coming on, you can try the security relearn.
huge problem after PCM update / calibration (PCM Security Relearn)

However, if after that it still doesn't crank or prime the fuel pump with the security light on, something is going on with the Passlock system. As @TJBaker57 said, it might be going into theft protection. That pushbutton bypass you did probably doesn't help the situation.
 

TJBaker57

Member
Aug 16, 2015
2,897
Colorado
agree it likely thinks you are trying to "hotwire" the vehicle. The push-start setup MUST be removed

There ARE specific circumstances where doing this, and doing it right does not confuse the security device. When I first got my trailblazer it had some intermittent no-crank issues. I took an old mechanics starter jump switch and connected it up to the starter solenoid and power and ran it out from the engine compartment near the windshield then in through the drivers door and left it on the dashboard. When I hopped in and turned the key to crank and nothing happened I then grabbed the mechanics tool and pulled the trigger and it started up fine. I was just paralleling what the starter system would have done if not for the intermittent bad connection which I eventually located and corrected.
 

TJBaker57

Member
Aug 16, 2015
2,897
Colorado
The starter that keeps cranking if you release the key before it starts is normal. The PCM will keep cranking for 3-5 seconds after key release until it starts or fails to start and will automatically stop. If it keeps cranking after it does start, I'd check the starter relay and the ground output to the starter relay from the PCM.

Does anyone happen to know when this feature was added? My early 2002 has never done this. Mooseman once said his 02 didn't do this until after some PCM update. Is it possible Chevygirls 2003 currently does not have this feature?
 

gmcman

Member
Dec 12, 2011
4,656
There ARE specific circumstances where doing this, and doing it right does not confuse the security device.

Absolutely, had to do this a few times also.

In chevygirls instance I get she needed to drive the vehicle, but hopefully we can figure this out as the bypass should not be needed long-term.
 

TJBaker57

Member
Aug 16, 2015
2,897
Colorado
leaving the grocery store and she would not start I had all lights on inside. I tried three times and she finally started.

Another clarification request. Did it crank but not start or did it not crank at all? When turned to the crank position did the dash lights go off as they normally do when cranking or did they stay on in the crank position?
 
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TJBaker57

Member
Aug 16, 2015
2,897
Colorado
Absolutely, had to do this a few times also.

In chevygirls instance I get she needed to drive the vehicle, but hopefully we can figure this out as the bypass should not be needed long-term.

I actually was slow to find my bad connection. Maybe a year or more! When I did find that one it was memorable. Once when I had time and it did not crank I took out my meter and started checking. Eventually got down to the starter & solenoid. For the solenoid coil stud & wire,,, I had power on the terminal ring,,,I had power in the washer,,,I had power in the nut,,,, the actual stud into the solenoid?? Dead. What!! All clean looking and tight, but no power. I had been taught this could happen in high school auto shop some 40 years earlier but had never seen it to that day! You have to test this stuff with a meter. Evidently I had just enough dissimilar metal type corrosion to inhibit the electrical connection there.
 

gmcman

Member
Dec 12, 2011
4,656
I just replaced my solenoid from a 3YO starter, found a local guy who had one. I'll link my post in a bit showing the solenoid part #.
 

budwich

Member
Jun 16, 2013
2,027
kanata
quote: "Did some research and it was my starter. So we replaced that, then the starter would not turn off it just kept running so we checked wires and fuses and were stumped so I took to a buddy he said it sounded like the ignition so he checked and said it was good. The starter has constant power running to it and can't find where."

This certainly leaves a bit to be desired in terms of understanding what is happening electrically. Without knowing exactly what terminals and states were checked, it is a crapshoot to diagnose. All the other "semantics" (banging the ignition, etc) readily point to the ignition switch as the focus. Basic test should provide the power state of the wiring with key in accessory, key on and key at start and go from the results.
 

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