Okay I have a 2009 Chevy Tahoe with a 4.8 4L60E transmission drove to a friend's house turned it off went to get in and tried to start no crank towed it home I replaced the internal mode switch battery starter starter relay starter fuses ignition switch PCM and are still getting no crank if I pull the relay out and I jump the starter relay with a wire It will crank over but will not start also I found two broke wires in my turn signal switch and just replace the turn signal switch to no avail . I did the relearn on the security system for the new PCM security light is not on battery is fully charged still have no crank can anyone please give me any information or knowledge on what I'm missing I'm at a complete loss here
No Crank help please
- Thread starter DubC75
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mikez71
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Have heard of a bad fusebox once or twice.. You'll need to check relay socket for adequate juice and ground. Since jumpering socket works, maybe a break in the relay coil circuit?
strutaeng
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So you jump the starter relay and it cranks, but doesn't fire?
That rules out starter and control/power wiring to starter. But that also tells you have another issue why it's not firing. Can you check for spark and fuel pressure when that's happening? Maybe 2 issues getting compounded into one?
A "no-crank" and "crank-no-fire" are different symptoms and require different diagnostics. Are you in the rustbelt by any chance?
As a sanity check I would have a listen to the starter relay as a helper attempts to crank. If no sound comes from the starter relay, you must have a separate issue.
That rules out starter and control/power wiring to starter. But that also tells you have another issue why it's not firing. Can you check for spark and fuel pressure when that's happening? Maybe 2 issues getting compounded into one?
A "no-crank" and "crank-no-fire" are different symptoms and require different diagnostics. Are you in the rustbelt by any chance?
As a sanity check I would have a listen to the starter relay as a helper attempts to crank. If no sound comes from the starter relay, you must have a separate issue.
Does a scanner show that the transmission is in Park or Neutral? Have you tried cranking it in Neutral? Messing with the shifter while attempting cranking? Neurtral safety switch issue? A good scanner will show the status of each of the ignition positions and commanded status.
Since the starter relay was bypassed (pins 30 & 87) and the main wiring works, it means that there is a 'control' circuit issue. Either the relay control ground (pin 85) or the control side (pin 86) isn't working. Easy enough to test with a test light - there must be hundreds of YouTube videos on testing those circuits at the relay socket.
See the link below for the schematic, but double-check that I've selected the correct vehicle. Navigate to the same page for yours if needed.
According to the diagram (top left), the ECM supplies a signal to engage the relay, so the relay is power side switched. One of the lighter circuits on the relay socket should have a full time ground; the other is the enabling circuit. All you need to do is find out what's missing, and go from there.
Lastly, there have been some fusebox issues with these, but don't let that sidetrack you until the data tells you to look there.
Since the starter relay was bypassed (pins 30 & 87) and the main wiring works, it means that there is a 'control' circuit issue. Either the relay control ground (pin 85) or the control side (pin 86) isn't working. Easy enough to test with a test light - there must be hundreds of YouTube videos on testing those circuits at the relay socket.
See the link below for the schematic, but double-check that I've selected the correct vehicle. Navigate to the same page for yours if needed.
According to the diagram (top left), the ECM supplies a signal to engage the relay, so the relay is power side switched. One of the lighter circuits on the relay socket should have a full time ground; the other is the enabling circuit. All you need to do is find out what's missing, and go from there.
Electrical Diagrams — 2009 Chevrolet Tahoe 2WD V8-5.3L Service Manual | Operation CHARM
Detailed repair manual for the 2009 Chevrolet Tahoe 2WD V8-5.3L.
charm.li
Lastly, there have been some fusebox issues with these, but don't let that sidetrack you until the data tells you to look there.
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probably going to need a scanner that is at least mid-level, comparable to a tech2
to troubleshoot further.
the scanner will show what is and what is not happening when the key is turned to start
outside of that I would check and inspect each fuse
Electrical - No Start/No Crank/Int Electrical Operations — 2009 Chevrolet Tahoe 4WD V8-5.3L Service Manual | Operation CHARM
Detailed repair manual for the 2009 Chevrolet Tahoe 4WD V8-5.3L.
charm.li
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What they said.
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.yessir I do have a legit scanner and I will go back out and get the exact details, but it does show to be in park and as far as all the ignition test and functions on the scanner they looked good , I m going back out now and my scanner links to the wifi so I will post the scanner images on Here
Yessir I have the scanner and it shows to be in park and all the different ignition fazes when I turn the key to various positions and will post the pictures from the scanner in a few since the scanner links to WiFi and I can send screen shots I think, and thankyou bin advance
I'm down in Texas , and I have fuel pressure and I pulled the wire from the plug inserted a crew driver and was getting spark but I'm going to pull the plug as well to see if it is getting for all the way through
one thing to check is what it says under security, even though the lock is not shown on the cluster.
I would also look at live data with the key in the run position and see what everything is showing, it should show some kind of clue
true/false/enabled/disabled/on/off, etc it's not always something glaring you in the face
did you check all the fuses?
funny thing when looking at the factory manual diagnostic procedures, something as simple as a keycard, like one on a key ring near the ignition switch can cause interference and a no start.
I would also look at live data with the key in the run position and see what everything is showing, it should show some kind of clue
true/false/enabled/disabled/on/off, etc it's not always something glaring you in the face
did you check all the fuses?
funny thing when looking at the factory manual diagnostic procedures, something as simple as a keycard, like one on a key ring near the ignition switch can cause interference and a no start.
what you want to try and look for a is a DTC Pxxx OR Uxxx, Bxxx code, if there is one, the ending 3/4 numbers define the diagnostic tree to use.
07burban88
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what part of Texas, I'm just a few miles north of Houston, if ya close and can get it to my shop I'll be happy to do a diagnostic on it and help
I'm up by Abilene . Thankyou so very much for the offer and kindness. I'm going to post an update on what I found
Your absolutely right and when I had the scanner hooked up I checked and made sure the security was good and that the responded I'm each position on the scope
UODATE: Bit not out of the woods as of yet. First off all thank you all so much for the quick and very intelligent and knowledgeable responses and advice . I found a short to starter relay circuit and chased wires for awhile. Found that my starter fuse had. Short to ground, all pins on the relay gave proper reading or no readings as per diagnostic checks , for the life of me I could not find why the fuse has a short to ground .. I sat for awhile and researched and researched till my brain could not comprehend what I was reading. Then I started talking to myself... I said self one of the wise members of your forum suggested fuse box, and you blew it off as surely that couldn't be the issue. Well I did .some digging and yes I completely forgot that you can split a fuse box carefully. OMG STEVE look what I found! So I have one on the way been checking all wires on the meantime and when it comes in I will let y'all know. Sorry for the book. And thank you all again.... MERICA
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then there must be a break or something interrupting between the ignition switch and starter relay
there must be a code in there somewhere and/or a, pxxx, uxxx, bxxx code
haah you posted before I did, houston I think you found the problem
