I replaced the engine with an 05 4.2 in my 04 TB and when I tried to start it would not crank. The security light is on solid and I tried the relearn but the sec light never goes off. Is there anything I can try at home and can this be fixed by a mobile tech nowadays? Everything seemed to work fine before the engine swap except the misfire on #6
SOLVED! 04 TB LS engine r&r security light solid no crank
- Thread starter Livnonthedge
- Start date
Sounds like security wasn't relearned properly. I've read it can takes multiple times for the relearn to succeed, i would keep relearning until it works - assuming you're following the correct steps. Then you would need to find yourself a Dealership or Tech 2 scanner to relearn CASE aswell.
I have left the key on for an hour and the security light stayed on. When I have the key turned on the key fob works but doesn’t when out of the ignition
Mooseman
Moderator
Which PCM did you use? The one original to your truck or the one that came with the engine? There may be a difference between the two years so use your original PCM. If using your original, the VATS shouldn't know the difference.
If the light never goes out during the relearn, there might be another fault in the system, like the key switch sensor. You might need someone with an advanced scanner capable of scanning more that just the engine codes.
Another way around this is to have the PCM tuned to turn off VATS.
If the light never goes out during the relearn, there might be another fault in the system, like the key switch sensor. You might need someone with an advanced scanner capable of scanning more that just the engine codes.
Another way around this is to have the PCM tuned to turn off VATS.
I’m getting power to the pcm via connectors,where do I look next? Nothing has changed still no crank and can not get the security light to blink. My dash lights cannot be turned off unless I unhook the batt.
Mooseman
Moderator
What's been done since? You get the PCM tuned? That shouldn't change the behaviour of power or dash lights.
Did you check the ignition switch for proper operation? It's normal for stuff to stay on for about 10 minutes during retained accessory power (RAP). If it doesn't turn off except after the 10 minutes, then the door latch switch isn't working. Open the passenger door to test.
Did you check the ignition switch for proper operation? It's normal for stuff to stay on for about 10 minutes during retained accessory power (RAP). If it doesn't turn off except after the 10 minutes, then the door latch switch isn't working. Open the passenger door to test.
I talked to Jeremy at limequat and he suggested I should look somewhere else(he didn’t think the pcm was the problem) So I checked for power at pcm and had power on the 4 pins.
Mooseman
Moderator
No but why would they be unplugged?
So I don't know what transpired with Jeremy but the symptoms you were giving us here indicated a problem with the VATS.
Questions that have not been answered yet:
- Which PCM are you using? Your original one or the one from the donor truck?
- Has the ignition switch been checked or replaced?
- Has anything else been changed or modified?
The symptom of the security light being on solid and the security relearn not working is telling me that there is something else going on. Quite possibly the sensor in the key switch is not working and telling the BCM and PCM that the key switch has been damaged. That's why I suggested that VATS be disabled in the PCM so it would ignore that. Maybe @limequat can chime in here if I'm wrong.
Now you're saying the power won't turn off. That may indicate a problem with the ignition switch.
So I don't know what transpired with Jeremy but the symptoms you were giving us here indicated a problem with the VATS.
Questions that have not been answered yet:
- Which PCM are you using? Your original one or the one from the donor truck?
- Has the ignition switch been checked or replaced?
- Has anything else been changed or modified?
The symptom of the security light being on solid and the security relearn not working is telling me that there is something else going on. Quite possibly the sensor in the key switch is not working and telling the BCM and PCM that the key switch has been damaged. That's why I suggested that VATS be disabled in the PCM so it would ignore that. Maybe @limequat can chime in here if I'm wrong.
Now you're saying the power won't turn off. That may indicate a problem with the ignition switch.
I have tried both PCM’s same result
I have not checked ign switch but was fine before engine r&r
There are no mod that I’m aware of
Headlights out for engine r&r
I have not checked ign switch but was fine before engine r&r
There are no mod that I’m aware of
Headlights out for engine r&r
Mooseman
Moderator
Another thing to check is the ground wires on the block. They are located on the lower driver side.
Do you have a scan tool? Any codes? Can you communicate with the PCM? I'd would suggest a bluetooth dongle with Torque Pro on an Android device. There is also the Chevrosys app that can scan all modules and see if any aren't communicating and see if there is a VATS code.
Do you have a scan tool? Any codes? Can you communicate with the PCM? I'd would suggest a bluetooth dongle with Torque Pro on an Android device. There is also the Chevrosys app that can scan all modules and see if any aren't communicating and see if there is a VATS code.
I had a chance to get back at the TB, I bought a new battery and decided to look over all connections and grounds. Everything was connected and tight so I connected the battery and went over everything again but this time if I wiggle the neg batt cable it starts cranking over and must disconnect the batt to stop.
Rather "strange". Doesn't sound like the wiring / grounds are right. Maybe you forgot something being connected during some of your earlier testing and now its coming into play. Is the theft light still on? Did you play with the ignition switch at some point just before this time / post?
Further what is this "all the connection are tight... but if I wiggle the negative battery cable, it tries to start"? your connections aren't tight if they are wiggling. Having said that, interior copper cables can have problem with corrosion getting past crimps or otherwise especially on high current cabling.
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The neg battery cable has a frame connection before it connects to the block,I checked to make sure grounds were tight on the block. I moved the secured neg cable and it cranks,I suspect the cable is not supplying a good ground? I will check out the ignition starter switch in the morning
Yes, that engine ground IS the MAIN ground for the system as it handles the "high current" needs for cranking among other things.
You likely have some other issues therein related if the thing cranks / continues to crank especially without the key set in place. Having said that, the state of modules may be "dubious" with poor grounding in general... so you might need to ensure you have good ground and then disconect power at the battery and let sit for a while to "drain" any residual charge. Re-connect at the battery. Do not attempt a key start. Only turn key to ON and closely observe dash indications and system "re-actions". Go from the result.
You likely have some other issues therein related if the thing cranks / continues to crank especially without the key set in place. Having said that, the state of modules may be "dubious" with poor grounding in general... so you might need to ensure you have good ground and then disconect power at the battery and let sit for a while to "drain" any residual charge. Re-connect at the battery. Do not attempt a key start. Only turn key to ON and closely observe dash indications and system "re-actions". Go from the result.
Mooseman
Moderator
Just one thing about cranking and it doesn't start. It will keep cranking for about 10-15 seconds if it doesn't start and then stops. Don't know the official name but I call it "flick start". Flick the key and it cranks by itself. Very normal. However, it will keep cranking beyond that if you hold the key in the crank position.
Chickenhawk
Member
- Dec 6, 2011
- 779
I put a new battery in and replaced the negative battery cable,the starter switch checked out fine. Now when I hook up the battery it starts cranking over, I disconnected power from starter so I could try to get the security light off and check any codes(no codes stored and now the security light is off). So with the power cable off starter and signal wire on I can hear the solenoid clicking on when I attempt to start. My key fob works like normal now as well,do you think it has to cycle those 10-15 seconds? I only left it cranking for 4-5 seconds so far
Mooseman
Moderator
If it starts cranking as soon as you connect the battery, something is wrong. My guess would be a shorted relay or something in the fusebox shorting to power. Does it stop cranking when you pull the relay? If not, I would also suspect a bad solenoid on the starter or something shorted in it.
So Mooseman... all knowing master.... is there any "system requirements" on bcm "lineage"? Having seen in the past, posts about engine swaps with years, with various "requirements" in terms of cabling, mounts, etc including PCM.... but what about the BCM... is there some sort of "match requirement" also?
Instead of disconnecting the power at the starter, pull the starter relay (without the battery connected... to prevent any sparking). The starter should not be happening and then you can do all kinds of checks to find out what's going on.
Having said... whom installed the starter... was it with the swap motor or transferred over? Check to ensure that the two leads at the starter are not touch each other somewhere near the contact area... not much room in there if I recall.
Mooseman
Moderator
Oh yes my padawan, you have to stay within the same generation of trucks. 02-05, 06-07, 08-09. In any case, if a PCM is swapped within that generation, all it needs is the 30 minute security relearn. In this case with a "new" engine, he would have kept the wiring from his truck. The BCM wouldn't know otherwise. The only thing the PCM would need, whether he kept the original to the truck or the one that came with the engine, it would eventually need a CASE relearn but it would not prevent it from starting and running.
There's definitely something up with the starter circuit. I doubt it's the PCM. Starters are all the same so that doesn't matter. In fact, I kept the new starter from my old 02 for my 07 in case it ever needs it.
I’m back on the road and I appreciate the time,expertise of Plat515,Mooseman and Budwich! So between a sketchy neg batt cable and my stupidity(batt cable on starter not positioned properly DUH!) The engine runs good so THANK YOU FELLAS and GMT!
Ok. granted this is a long shot, but you never know. Did you check the oil level and oil level sensor. If you turn on the ignition at any time when the oil level is too low, ( as might happen when you are changing oil and want to turn on the radio), the ECU will set codes that will disable the ignition and must be cleared first.
Fixit
Fixit
Mooseman
Moderator
His is an 04 and the engine is an 05. The oil level sensor was only in 02 and didn't do anything except tell you to check oil level when your start it. And he did solve it so...?