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1996 Sierra CMP and CKP Sensor


KevRho
12-10-2003, 07:02 PM
I have a 1996 Sierra and my SES indicator light tripped with a p1345 code. Does anyone know how to determine which sensor is tripping without replacing them both? If I use a DVM, can I check for resistance and what would the values be? Any help is greatly appreciated.

GMMerlin
12-11-2003, 07:05 AM
Have you had the distributor out for any reason?

Usually when I see this code, someone has removed the distributor and reinstalled it incorrectly or the distributor gear is severely worn.
You cannot "set timing" on those vehicles, but there is a way to adjust the distributor so it is in the correct position.

KevRho
12-11-2003, 04:42 PM
As a matter of fact, this all started after I replaced the intake manifold gasket. I had some problems re-installing the distributor. I thought I may have damaged the sensor socket pins or perhaps the plugg itself, but there is no visible damage. Do I need to re-install the distributor again? The first time I had it 180 out. I made the mistake of trusting my wifes ability to tell the difference between the compression stroke and the intake stroke at the number one cylinder. The second time I used a balloon at the end of a hose to a compression gauge. I then lined up the rotor to the number one pin on the cap, notated the position and installed the distrbutor. The truck ran well for awhile even though the service engine light is on. Now it's intermittently cutting out at cruise speeds.

GMMerlin
12-11-2003, 06:13 PM
Well here is your problem....you will need a scan tool to adjust the distibutor. You will have to set the cam offset angle to 0 degrees at 2000 rpm.

KevRho
12-12-2003, 12:51 PM
That would certainly make sense. Would this scan tool be the same OBD11 tool I used to read the code? I didn't see a funtion on there allowing me to read the offset angle. Once I have the tool, I assume I would set the angle the same way I would adjust the timming for a diffeferent vehicle by turning the distributor housing?

GMMerlin
12-12-2003, 03:21 PM
I don't think a code reader will work..a Tech2 or Vantage scanner will work.

I assume I would set the angle the same way I would adjust the timming for a diffeferent vehicle by turning the distributor housing?

Its the same procedure

KevRho
12-20-2003, 10:21 PM
Well, I attempted to try your solution but the borrowed scanner was giving me problems. I talked to one of our company mechanics who suggested I verify that the rotor was lined up directly with the #1 pin at TDC, which I did and in the process I found an interesting situation. The new cap I had installed last fall had a blueish carbon build up on each of the pins. I'm wondering if I installed a faulty cap and rotor. Secondly, the rotor does not have any register pins to make sure it only goes on one way. If I have that on the cam 180 out, could that let the truck run but still trip the code?

GMMerlin
12-21-2003, 07:01 AM
The engine will not run 180 out.
The SES light will set if the cam offset angle is about 7 degrees or more off.

Listen to me carefully...set the camshaft offset to 0 degrees and that will fix your problem!

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