1999 Chevy Tahoe P01340 cam sensor malfunction?!?!

1999 CHEVROLET TAHOE
121,912 MILES • V8 • 4WD • AUTOMATIC
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BROOKLYNJIM
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well.. after 3 cam sensors (inside dist), 3rd being dealer, going thru ALL the wiring, replacing the crank sensor, re-indexing the distributor, im still getting the CIL and the code..

this has been an ongoing thing for over a year now, ive never had an issue with starting, always starts right up in any weather,

i can erase the CIL, the truck will start and restart a few times before the code and CIL comes back..

any ideas guys?

i even swapped in a used ECM, same make/model and options codes, to elliminate that possibility, yah, that was fun, reprogramming the passlock!!
Oct 12, 2010 at 5:01 PM
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RASMATAZ
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Hi BrooklynJim, Welcome to 2carpros and TY for the donation

P0340 Camshaft Position Sensor Circuit Malfunction

P0340 could mean one or more of the following has happened:

•a wire or connector in the circuit could be grounded/shorted/broken
•the camshaft position sensor may have failed
•the PCM may have failed
•there exists an open circuit
•the crankshaft position sensor may have failed
Possible Solutions With a P0340 OBD-II trouble code, diagnosis can be tricky at times. Here are some things to try:

•Visually inspect all the wiring and connectors in the circuit
•Check for continuity in the circuit wiring
•Check the operation (voltage) of the camshaft position sensor
•Replace the camshaft position sensor as required
•Check the crankshaft position circuit as well
•Replace circuit wiring and/or connectors as required
•Diagnose/replace the PCM as required
Oct 12, 2010 at 7:09 PM
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BROOKLYNJIM
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•Visually inspect all the wiring and connectors in the circuit.... DONE, CHECKED OUT GOOD, BY MYSELF AND THE DEALER

•Check for continuity in the circuit wiring....... CAM SENSOR WIRING WAS CHECKED BETWEEN SENSOR PLUG AT DIST, AND ECM, GOOD

•Check the operation (voltage) of the camshaft position sensor, CHECKED, BOTH PREVIOUS WERE WITHIN SPEC BUT REPLACED ANYWAY WITH A DEALER SUPPLIED UNIT

•Replace the camshaft position sensor as required
REPLACED 3 TIMES, ON 3RD NOW

•Check the crankshaft position circuit as well..... CHECKED, RESISTANCE WITHIN SPEC, HARNESS ALSO CHECKED, ALL GOOD


•Replace circuit wiring and/or connectors as required... NOT DONE YET (COULD IT BE?) AND THE DEALER DIDNT CHANGE?


•Diagnose/replace the PCM as required... REPLACED WITH A USED ECM FROM ANOTHER SAME YEAR/MAKE/MODEL AND EVEN RPO CODE TAHOE, SAME ISSUE
Oct 12, 2010 at 7:19 PM
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RASMATAZ
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The sensor is good 3rd one to include the CPS voltage/wiring good to the computer and a used PCM-my last resort is flash the PCM and see what happens-Don't work this is as far as I can take you I'm sorry
Oct 12, 2010 at 7:31 PM
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BROOKLYNJIM
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flash the PCM? the oem pcm? you lost me with that one? im assuming thats a dealer thing isnt it? or can it be done with a snapon 2500?
Oct 12, 2010 at 7:33 PM
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RASMATAZ
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That's if you have the software to do it otherwise the dealership has to do it-
Oct 12, 2010 at 7:42 PM