OBDII code P1345 ?

[gregory914]

Does anyone know any details on the P1345 code? About three months ago I resset my OBDII, it only had one code (the one above) and the device said "engine misfire". Wich I assumed was from one of the times I shut the truck off to get the damn wipers to park in the down position, by shutting it off then quickly restarting it. For the last week or so it's been coming on almost every day at least once and stays on for a while then goes off and may not come on till the next day or two or three.

I stopped at my local Auto-Zone store and they got the same code that was stored before, P1345 and "ignition engine misfire" text. They ran it through their computer inside the store and it said "SGC (Cam Position) Sensor Circuit Malfunction". Does this mean the cam sensor is bad? And when do I really need to replace it? The truck runs fine and fast, has 109k miles on it and the milage is 12-13 mpg in the city stop and go, and I consistantly get 17.7 on the freeway doing about 80-85 mph. I also just put a new fuel pump and filter in about 900 miles ago and gained about 30-40 HP!(or so it seemed). The only mod to the truck is a K&N air filter in the factory optional "High Capacity Air Cleaner".

If it is a Cam Sensor, how do you know when it's not working and how do you change it? I was also wondering if it could be the electrical connection to or from the sensor. I bought my Burb new, it is a 97 K1500 with 109k miles and has had doses of Techron twice a year and only eats premium fuel. I have never had any codes except for an O2 sensor thet was replaced under warranty at 40k miles.

Any HELP!!!
THANKS

[Sub5]

I checked my shop manual and the proper code identification for a P1345 is "Crankshaft position sensor / Camshaft position sensor correlation". Same code for both and it either is malfunctioning or needs adjustment.

[gregory914]

Thanks for looking that up. Do you know if there is a specific test I can do at home or is this a dealer issue. Are there any symptoms when the sensor is not functioning properly or any way to adjust it?

Like I said the truck runs great. I'm wondering if I should just drive it till it breaks. But then......what happens when it breaks? Will the truck just die.

I just had a thought; with the miles on this at 109k could the cam chain and sprockets be worn enough to be giving the code, but not worn enough to make it run any different? It usually lites the SES lite when I first start it, and now with the new fuel pump it fires up with a quick flick of the key wich may be putting some back lash in the cam chain and giving me the error code. Anyone...any thoughts or am I over thinking this?

[Mikado14]

Sounds to me that you might be "overthinking it". To check for timing chain stretch, use a timing light on #1 cylinder and make note of the timing, then put the pick-up on #4 ( having a brain fart on this but it will be the 5th cylinder in the firing order). Make note of the mark. You may also have to disconnect the PCM timing connector located under the floor mat on the passenger side under the dash. It will be a 5/16" black connector with a small brown or beige wire.

[gregory914]

Thanks, I assume the timing should be the same on #1 and #4 because the distributor is 180 degrees from #1. And about how much of a difference is acceptable? Also where is the cam position sensor?
THANKS

[Mikado14]

Never ran across it in a book, however, I remember something about 10 degrees or more you should consider changing.

[Sub5]

Haynes shop manual has all OBD2 codes listed with description. As well as many other shop manuals.

[Jeremy-WI]

Has anyone attempted to adjust the timing by turning the distributor, or have the intake manifold gaskets been replaced before the code showed up? The timing is non adjustable on 96 and newer. You should have a scan tool to set the distributor correctly. You can get the engine to tdc on the compression stroke of cylinder #1 and check where the rotor is pointing in the distributor. It should be pointing at a "V" shaped pointer with an 8 on it in the distributor housing, if it isn't turn it so it does line up with the 8.

There have been some issues with distributor gear wear that could cause this too

[gregory914]

The SES light is on all the time now, can anyone tell me where the cam positoin sensor is located?

[gregory914]

I just saw a new post on a "97 starting problem" (2-16-05) and someone mentioned replacing the crank and cam sensors. Haven't had time or money to pusue my P1345 code but if my burb doesn't start I'll have to!
With that said, should I peplace the crank and cam sensor and where are they located??? I'm thinking they might be in the distibutor or on the cam chain cover ? ANY HELP OR ADVICE, PLEASE!
And oh yeah, my SES light is on almost all the time and with the same code showing up after I cleared it several times so I have a good /bad feeling that somethoing is not right but so far it runs fine.
THANKS

[Jeremy-WI]

There is a very good chance that replacing cam position or crankshaft position sensor will not fix this problem. This code tells you that the base timing of the vehicle is not correct. You really need to get the vehicle scanned with a scantool that will read the cam retard with the engine running over 1200 rpms and then make adjustments by turning the distributor, unless it is timing chain/gear stretch/wear or wear on the distributor gear. You could mark the current distributor orientation and turn the distributor counterclockwise, clear the code and start the vehicle and rev over 1200 rpm to see if it comes back, but the scan tool that can read the cam retard is the best way.

FYI The cam position sensor is in the distributor and the crankshaft position sensor is mounted to the bottom of the motor near the balancer

[Old Dave]

I just went through this on my 97 GMC Suburban. My son and I replaced the leaking intake manifold gaskets and marked the distributor very well to get it back in the same position. The crank was not moved while the distributor was out. We dropped it back in and lined up our marks like it was when we removed it, and when it fired up the SES light was on all the time. It didn't seem to run quite right, idled ok but didn't seem as zippy as before we worked on it. The mechanic said the distributor was off slightly so it wasn't timed right but the cam sensor was bad also. He said there is a mark on the balancer and another one (a "V") on the timing chain cover and these have to be lined up when #1 is at TDC. Then there is a "8" mark on the distributor that has to line up with the pointer on the rotor and a mark on the intake. He said the cam sensor was bad because he couldn't get it any closer than -17 degrees and it's supposed to be 0 deg. plus or minus 2. Runs great now. I think the key is having the scanner that will read live stream data, but I don't have the 4K to buy one of those. BTW, the cam sensor is in the distributor and the crank sensor is in the front of the oil pan on the right side behind the balancer. Good luck with yours.

[gregory914]

Thanks, I guess I'll take it to my dealer to have them chack it out. But, so far it's running great, both performance and economy wise.
Hope I didn't jinx myself!!!!!
I'll update you guys when I finally take it in.

[ohiahlberg]

Originally Posted by gregory914

Thanks, I guess I'll take it to my dealer to have them chack it out. But, so far it's running great, both performance and economy wise.
Hope I didn't jinx myself!!!!!
I'll update you guys when I finally take it in.

I replaced the engine i my 97 suburban with a target engine from Chevrolet. The swap went great and the engine is running fine. I have had a P1345 code that turns the service engine soon light on. I have been dealing with this for a month, Finally I found in your fourm about turning the distributor cap, I turned it counterclockwise and after about 5 times no mofe light, Yeah!!! I love the Internet!! Thanks guys that saved me $100-$200

[gregory914]

I have finaly figured out what my problem code was telling me. Jeremy-WI and I were both on the right track, the code was correct in reporting the crank and distributor were out of sync. I thought the weak link would have been the cam chain but as it turns out it IS the distibutor gear.

Last week I went to my buddies shop to balance my tires and I metioned about having the SES light on for about a year now and that the code was for a cam position/ crank timing. He then proceeded to tell me that in the 97 and 98s, as his K2500 P'up is, that the gears were soft and they would actualy wear enough to through off the timing and you could try to adjust the timing but at some point you'll run out of adjustment.

The real big problem, that happened to him was that gear is also hooked to the oil pump and he lent his truck to his son's Boy Scout troop and wile going down the freeway at 75 or so it strated to mis-fire and backfire because the timing was so far off and yes the oil pressure went to ZERO and Paul now has a new GM factory replacement long block in his truck($2750) and he did the swap out himself.

Until six months ago he didn't realized this is a common problem with that vintage of GM distributors because you could usually adjust the timing enough to get the code to go away but you are just masking the real problem. He is a GM certified Tech, worked at an Olds dealer for 10 years before opening his own place, but he had never herd of this as being common. He then proceeded to show me a box with about 25 to 30 gears all worn the same way and all from 96 thruogh 99s that had SES lights on. And now with a $40 part and less than two hours labor and ten minutes on a scanner all these 100K mile trucks run fine and can pass our E-check here in Ohio.

So before you start buying sensors and other misc. parts , try the gear if you are getting a P1345 code. I was surprised at the wear because I religously used Mobil 1 and can only put the cause on the GM parts supplier.