service end soon light turn off?

Schurkey · Jan 18, 2021

[email protected] said:
1997 Chevy Tahoe 5.7 .

code P1345 is back .Timing says set at 0.
Engine has new cam senser and all was good before I changed intake Gasket.

b454rat said:
I think I had the same code on my 98 tahoe. Timing was off just a little bit, enough to set the light. Buddy at garage hooked up to scanner, tried all the steps but wouldn't go off. Ended up just lightly twisting distributor and light went off.

east302 said:
the CMP Retard (or offset or CKP/CMP Correlation). Two different things - the second is the one that gets thrown off when a distributor is removed. Easy to set with a scanner or certain Bluetooth apps.

P1345 is CMP Retard, which is the cam sensor-to-crank sensor synchronization.

This has NOTHING to do with ignition timing. You can turn the distributor all day long, and not "change the timing" unless you turn it so far that the spark jumps to the wrong cylinder. The ignition timing is set by the CRANK sensor, not the cam sensor.

The two sensors need to be aligned, or synchronized, so that the computer knows which cylinder is misfiring, and so the rotor tip-to-distributor cap terminal gap is minimized.

As said...easy to do with a scan tool. Turn the distributor so it's within 2 degrees of perfect alignment, tighten the hold-down bolt.

b454rat · Jan 18, 2021

It was hooked to a scan tool and didn't work. It wasn't off by much, cause ran the same as before. But when he turned the dizzy, which moved maybe an 1/8", and it cleared. The PO of the my Tahoe said he replaced the intake gaskets, and obviously didn't line it up correctly.

makindust2@aol.com · Jan 19, 2021

The Code is P1345. Like I said my hand held acton scanner reads that code but when I check data timing is set at O
I am taking the truck in for inspection today and see what he reads with his scanner.

east302 · Jan 19, 2021

Just making sure that you’re looking at the right value, is your scanner reading the timing or the CMP Retard? It’s two different things, the CMP offset is what usually causes that code to be thrown and a lot of scanners cannot read it. That’s the number that you’re looking for.

An accurate value is read at 1,000-rpm.

If the CMP retard is at zero at 1,000-rpm and you’re still getting the code, then that’s another matter.

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service end soon light turn off?

Schurkey

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