2004.5 LLY Engine Issue

[2_60b4u]

Hey guys, I just bought my truck last month and the other day my engine started knocking extremely bad and it won't accelerate over 5mph.

Codes stored are:
[PCM] P0203 - Injector 3 Control Circuit (SES) (History) (Immature)
[PCM] P0205 - Injector 5 Control Circuit (SES) (History) (Immature)
[PCM] P2149 - Injector Positive Voltage Control Circuit Group 2 (SES) (History) (Immature)
[TCM] P0742 - TCC System Stuck On (Old) (Current) (Immature)
[Restraints] B0026 - LF/Driver Frontal Deployment Loop (Single Stage or Stage 1)Open (History) (Immature)
[Restraints] U1000 - Class 2 Communication Malfunction (History) (Immature)
[Entertainment] B1025 - Driver Deployment Loop Short to Voltage (History) (Current) (Immature)
[Entertainment] B1235 - (History) (Immature)
[Entertainment] U1000 - Class 2 Communication Malfunction (History) (Immature)

Truck appears to have had injector connector kit for #2 and #7 +#5 replaced less than 20k miles ago according to dealer receipts. I double checked the wire loom next to the alternator and it's already protected with some type of rubber hose.

Tonight I replaced the fuel filter and ice picked #2,#3,#5,#7. Truck ran absolutely perfect once I started and let it warm up for 5 minutes. Shortly there after the check engine light returned and so did the loud knock.

Current codes:
PCM] P0202 - Injector 2 Control Circuit
[PCM] P0208 - Injector 8 Control Circuit
[PCM] P2149 - Injector Positive Voltage Control Circuit Group 2

[yfzgoody]

Seems like you got an issue with the drivers side. Computer sees an open/short on the injector and shuts down that bank of injectors. I would double check where they have insulated/repaired around alternator bracket. You might try some electrical connector cleaner when you take the connectors off and dielectric grease.


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[yfzgoody]

Bump for ya. Hopefully someone else might chime in.


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[jc1843]

Check this first--. At the side of the alternator, there is a big wire harness with a plastic loom. The harness is tied down to the FICM bracket with a tie strap. Cut the tie strap and inspect the wires in the loom. The sharp corner of the FICM bracket cuts into the loom and shorts the wires.

If that is OK, you may have injector connection problems. Common for the LLY. When the computer sees one injector not firing, it can shut down that group of injectors. Many jhave been able to tighten the terminals in the injector connector, using a sharp "Ice Pick". Usually #2 and #7 are the one that cause problems.
[searching that will give you a lot of information.]

GM does have a kit to replace the connectors.

The cylinders are numbered -- passenger side [right] 1-3-5-7, and the driver's side [left] is 2-4-6-8.

[2_60b4u]

Originally Posted by yfzgoody

Seems like you got an issue with the drivers side. Computer sees an open/short on the injector and shuts down that bank of injectors. I would double check where they have insulated/repaired around alternator bracket. You might try some electrical connector cleaner when you take the connectors off and dielectric grease.


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I'm going to open up the large wire loom and clean out + apply dielectric grease to all the injector connectors tonight. I'll report back with my findings.

[2_60b4u]

Originally Posted by jc1843

Check this first--. At the side of the alternator, there is a big wire harness with a plastic loom. The harness is tied down to the FICM bracket with a tie strap. Cut the tie strap and inspect the wires in the loom. The sharp corner of the FICM bracket cuts into the loom and shorts the wires.

If that is OK, you may have injector connection problems. Common for the LLY. When the computer sees one injector not firing, it can shut down that group of injectors. Many jhave been able to tighten the terminals in the injector connector, using a sharp "Ice Pick". Usually #2 and #7 are the one that cause problems.
[searching that will give you a lot of information.]

GM does have a kit to replace the connectors.

The cylinders are numbered -- passenger side [right] 1-3-5-7, and the driver's side [left] is 2-4-6-8.

Thanks for the info!

[2_60b4u]

I cleaned and applied di electric grease to # 2,4,6,8 (noticed #6 wire loom had rubbed a hole so I inspected the wire but didn't see any bare wire, taped it all up nice and good and re insulated it.) Re connected everything and fired it up. I didn't reset the computer but the check engine light was off then not more than 45 seconds later the light came on and the truck is back in limp mode.

Side note- I'm using key #2 and its reading on the display as key #1. This same key has shown up as key #2 all other times.

[yfzgoody]

Not sure what to say about the Key reading different numbers. But I would start tracing wires and making sure all if good. You never know what they possibly could have done when they "fixed" the connectors. Also knowing what codes are being thrown will help out your troubleshooting and help those helping you.


Also after you done the ice pick on those connectors, when you plugged them back in did you actually have to apply some pressure to get it snapped back in? When mine messed up it was #2 connector. Unplugged it and plugged back it and it ran perfectly fine. However it didn't feel right to me. The connector slid on and off easily. After picking that connector I actually had to use a little force to get it clipped back in.


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[2_60b4u]

I did have to apply pressure but the grease definitely made it easier.

I forgot to mention that I replaced # 2,3,5,6 with a new injector connector harness and soldered the connections.

Here's a link to my original post on another forum that I posted originally.
2004.5 LLY Engine Issue - Dmax Central

[jc1843]

The keys used in the 04.5 and 05 are not chipped so it does not make any difference which key you use.