Topic: p1345 on gmc

[mwilder]

I have an error p1345 "cam sensor/ crank sensor relationship error" since I changed the sensor. Clearing the code only helps for a few minutes, it comes back. I have read elsewhere that you must force the ecu to "re-learn" the crank to cam parameters. How do I do this with proscan/elm322?
I am new to this field and completely fascinated with it.
Please give some advice to a newbie!

This is on a '95 GMC jimmy (obd2 - one of the early ones), using proscan software and the elm322 interface that came with it.

[hornerm]

mwilder

I have the old book on OBDII for 95 Blazer (same as Jimmy). Will look for tonight and look up the tracker code (p1345)

Ray

[markowensbarlow]

  I have P1345 on my 1998 Chevy Astro Van.  After 187,000 mile it appeared first as pending then after another day or two as MIL.  Fearing the original timing chain was about to break, I opened it and found it to be about .5 inch side to side movement loose on both sides without the gears moving.  Replacing the chain and both sprockets with everything still synchronized in the cylinder 4 TDC position where all the dots are adjacent left the new chain tight on both sides with no perceptible movement due to finger pressure.  So this van should now have factory new synchronization between the crank shaft and the cam shaft.   After reassembly I verified that the signals in the wires out of the Hall Effect sensors in the distributor and Timing Chain Cover were good with my oscilloscope.  I also erased the only error code: P1345.  But every time I start the van, P1345 is right back relighting the MIL.  After erasing P1345 I can drive 35 miles to work with it never lighting the MIL.  So is the van's PCM computer pulling this P1345 up out of memory  or is it refinding the "fault".  If the latter, what are the possibilities for the "fault"?  To me the most likely are the PCM wires or connectors, or the PCM itself.  If the former, what must I do to get the PCM to forget P1345?  Is P1345 error only checked immediately after engine start up or when?

[swivelheadd]

P1345 appeared on my '96 Sonoma after replacing the Lower Intake Manifold, Distributer, and re-building the CSFI Fuel Meter Body.
The Distributer was replaced with the engine distirbed, so I'm assuming the code is related timing.  I'll send a reply to this thread when I figure it out.

BTW:  my Chilton manual lists the code as, "Crankshaft/Camshaft (CKP/CMP) Correlation".

[Dunnie]

Connect scan tester  to vehicle. Start engine and observe engine RPM. If RPM fluctuated up to twice desired RPM, replace faulty crand shaft sensor and retest. If RPM does not fluctuate up to twice desired RPM, check for proper installation of distributor

[swivelheadd]

My error code was due to a timing issue.   When I initially installed the new distributor, it was off by two teeth.  Correcting the problem resolved the error code.  

[bcon415]

Guys, I hate to reopen this topic, but I am having trouble with similar issues.  Got a "junkyard" engin, w/ guarantee, for 2000 2500express, 5.7L, and giving this code p1345.  It came w/ distributor loose, and approx 180 degrees off.  I put harmonic balance on tdc, or what I thought was tdc, righted distrib, cranked, and it runs, but runs at a bad idle, loping(idles, dies, catches itself, idles).  The mark on the balance is clear, but the mark on the block is not, and I might be a few teeth off.
What should be tdc?  Has anyone a pic from a manual, or anything "legal" they can send?
Thanks for any help.
Brad

[digdug]

bcon,

Check out the other topic on the board, I have the same issue.  If the CMP Retard is off by more than 2 deg it wont run or the engine light will stay on.

Doug.

[DeronK]

Guys, I hate to reopen this topic, but I am having trouble with similar issues.  Got a "junkyard" engin, w/ guarantee, for 2000 2500express, 5.7L, and giving this code p1345.  It came w/ distributor loose, and approx 180 degrees off.  I put harmonic balance on tdc, or what I thought was tdc, righted distrib, cranked, and it runs, but runs at a bad idle, loping(idles, dies, catches itself, idles).  The mark on the balance is clear, but the mark on the block is not, and I might be a few teeth off.
What should be tdc?  Has anyone a pic from a manual, or anything "legal" they can send?
Thanks for any help.
Brad

Hi Brad,

I just put a rebuilt 5.7 into my 98 GMC k2500. This is what I know so far about setting the timing. First, to find TDC take out #1 spark plug (should be front driver side) and place your finger over the hole (not in!) then have someone just tap the key to move the engine a small amount. You will notice when you are close to TDC because it will force your finger off. Then you need to look at the front of the timing chain cover. The balancer has a grove that should be lined up with mark on the cover. The mark is around the 2 oclock position. You may have to move the engine forward a hair to get them lined up. You might have to pull all the plugs to turn it at all by hand ;-)

Now that is done, you are at TDC #1. Take the distributor cap off. The point should be pointing to the triangular indent with a raised 8 on it. That will get your timing close. Twisting the entire distributor (if you loosen it of course!) should let you move before/after that point. Now you need to read Camshaft Retard Offset and twist the distributor to get it to 0 +/- 2 degrees. That is where I am stuck at. See my thread for some details.

If you look around with Google, you should be able to find some clear instructions that flesh out what I just wrote. Good luck!

Deron

[Berlincam86]

I had the same problem with a astrovan. It turned out to be the bushing on the top part of the distributor shaft were real bad. Check that the rotor holder doesn't move side to side.

[dietz4ibanez]

I have a similar issue with my 1998 GMC Sierra with a 5.7L 350. I am getting P1345 I just installed a new motor and thought that distributor was placed correctly. Truck runs perfectly fine but I am still getting the code. Could it be that I just need to rotate the distributor +/- to get the code removed?

[mikeleone]

This one tool me some time to figure out!  This happens when you drop in the distributor on a different cam tooth than it wants.  Turning the base does no good. There is a magnetic sensor in the block that has to line up with the crank sensor.  Pull the distributor and advance the rotor a cam tooth in one direction or the other.  If the code still comes up, go the other way.  The computer adjusts the actual timing once the distributor is on the right tooth.

[trickytransam]

Mike,

Usually on the later 350's the Intake manifold to Distributor is marked with a printed white line.
It's on the manifold and distributor flange.

I usually put#1 at TDC do a sanity check of where the rotor is sitting, and then line up the mark on the distributor flange to the manifold. The ECM does the rest for timing.

This has worked for me several times, without having to do a crankshaft relearn.
To find it, just wipe the area with a cloth - no solvents as brake kleen and similar will remove the mark.

You have to be in the neighborhood of where the rotor needs to be. A tooth off will make it chug and sometimes backfire if its a couple.
Hope this helps.

Oh... and while your in there - change those garbage intake gaskets. The DexCool has surely eaten them away to nothing. Go to a FelPro Metal Clad gasket, and Prestone All Make All Model.
Flush every drop of that Dexcool garbage out!

[stevehendo34]

"This happens when you drop in the distributor on a different cam tooth than it wants  There is a magnetic sensor in the block that has to line up with the crank sensor."

Are you saying you get a P1345 if you off a tooth regardless of CMP Retard being off.

My vortec 4.3 gets a P1345 on every start-up but I can clear it when running and it will drive with no service soon light until the next key cycle.  Do you think is because it is checking this block magnetic sensor only at start-up and has nothing to do with  CMP Retard.   

I just got the truck and do not have any history.  I starts very hard when cold wanting to jump out of the truck but starts smooth as glass when warmed up.  Also pretty bad gas mileage.