P1345 confirmed any info on how to fix this or what are somethings that cause this code other then the senser. It was on and off and seemed to stay on at same time cruise control stopped working.
crankshaft angle corralation advanced
- Thread starter wolf82
- Start date
Welcome to GMT Nation...
Unfortunately, this particular Code (P1345) indicates that the relationship between the position of the Crankshaft vs. the position of the Camshafts for the purposes of establishing the proper Timing of the Spark-Plugs Firing with the Pistons being in improper BTDC (Before Top Dead Center) positions. These positional irregularities can sometimes become catastrophic.
This is generally caused by the following issues with the GM 4.2L LL8 Atlas Motor:
(1) High Mileage Engine.
(2) Worn and/or Stretched Timing Chain.
(3) Fully Extended Timing Chain Tensioner.
(4) Worn Timing Chain Guides.
(5) Loose Harmonic Balancer Bolt and/or HB slipping with Damaged Crankshaft Dowel Pin.
(6) Any combination ...or All of the above Artifacts being involved.
(7) This requires a MAJOR Repair for a complete R&R of the Timing Chain Set + Tensioner.
Unfortunately, this particular Code (P1345) indicates that the relationship between the position of the Crankshaft vs. the position of the Camshafts for the purposes of establishing the proper Timing of the Spark-Plugs Firing with the Pistons being in improper BTDC (Before Top Dead Center) positions. These positional irregularities can sometimes become catastrophic.
This is generally caused by the following issues with the GM 4.2L LL8 Atlas Motor:
(1) High Mileage Engine.
(2) Worn and/or Stretched Timing Chain.
(3) Fully Extended Timing Chain Tensioner.
(4) Worn Timing Chain Guides.
(5) Loose Harmonic Balancer Bolt and/or HB slipping with Damaged Crankshaft Dowel Pin.
(6) Any combination ...or All of the above Artifacts being involved.
(7) This requires a MAJOR Repair for a complete R&R of the Timing Chain Set + Tensioner.
Last edited:
Mooseman
Moderator
@MRRSM , Time out here.
I had that code on my '02. Wound up being the cam phaser being bad due to poor oil maintenance by the PO. However, before thinking the worst in the timing system like the timing chain, especially if it runs fine, check the following easier things:
- CPAS (aka: VVT solenoid): check for oil in the connector, pull it out and verify the screens are still present. I'd replace it anyway just to eliminate that possibility (use ACDelco only).
- cam sensor: take it out and clean it.
- crank sensor: pull it out and clean it.
- get a CASE relearn done (requires a Tech 2 or other high-end scanner). It might fix it.
If the above fails, then it's something mechanical and you have to dive in deeper.
- pull the valve cover and check the chain guide shoes from the top looking down. They can sometimes break off but usually causes lots of noise.
- check the chain tension. It shouldn't be super tight but not floppy neither that it droops between the two gears. A bad chain tensioner is usually indicated by a noise only at idle.
- turn the crank by hand until the timing marks line up with the dark chain links on the gears, like in the image above. May take a few revolutions. If they don't ever line up, then you do have a skipped chain and will require further disassembly for repair and replacement.
If everything above checks out, then you likely have a bad cam phaser. It can be confirmed further if you have access to a Tech 2 or other high-end scanner to check and command the phaser. It can be replaced without taking off the front timing cover but requires some special hook tools to hold the chain. it is available new from Dorman. Don't bother with the rebuilt from ACDelco/Delphi as I had a bad experience with it but the Dorman did work out well for me.
I will be adding this thread to the FAQ.
I had that code on my '02. Wound up being the cam phaser being bad due to poor oil maintenance by the PO. However, before thinking the worst in the timing system like the timing chain, especially if it runs fine, check the following easier things:
- CPAS (aka: VVT solenoid): check for oil in the connector, pull it out and verify the screens are still present. I'd replace it anyway just to eliminate that possibility (use ACDelco only).
- cam sensor: take it out and clean it.
- crank sensor: pull it out and clean it.
- get a CASE relearn done (requires a Tech 2 or other high-end scanner). It might fix it.
If the above fails, then it's something mechanical and you have to dive in deeper.
- pull the valve cover and check the chain guide shoes from the top looking down. They can sometimes break off but usually causes lots of noise.
- check the chain tension. It shouldn't be super tight but not floppy neither that it droops between the two gears. A bad chain tensioner is usually indicated by a noise only at idle.
- turn the crank by hand until the timing marks line up with the dark chain links on the gears, like in the image above. May take a few revolutions. If they don't ever line up, then you do have a skipped chain and will require further disassembly for repair and replacement.
If everything above checks out, then you likely have a bad cam phaser. It can be confirmed further if you have access to a Tech 2 or other high-end scanner to check and command the phaser. It can be replaced without taking off the front timing cover but requires some special hook tools to hold the chain. it is available new from Dorman. Don't bother with the rebuilt from ACDelco/Delphi as I had a bad experience with it but the Dorman did work out well for me.
I will be adding this thread to the FAQ.
