Knocking, check engine light, emission and speed warning after NEW crankshaft sensor installed

[SC2CO_TAHOE]

Hi

My 22 Tahoe (26k miles) just got back from the shop after a 1.5 month wait for a new crankshaft sensor. I’ve had it less than a week and I get the same problem I had before the new sensor was installed. The car periodically knocks, the check engine light is on, I received a diagnostic alert to check the engine, transmission and emission system and I have a warning that I will not be able to go over 65 mph in 175 miles. So frustrating. Any body else have this issue and have it successfully resolved? Many thanks,

 

[StephenPT]

This is the second Duramax on this forum to have the crankshaft position sensor replaced and problem not solved. Dealers are just throwing parts at these issues.

What DTCs did you have the first time? What DTCs do you have now after the sensor was replaced.

The other thread in this forum about the crank sensor being replaced mentioned that the dealer is now looking at chaffed wire harnesses since sensor replacement wasn’t root cause.

Check in that thread - there’s a link to a TSB GM published that shows common locations to look at for pinched/chaffed wiring harnesses.

 

[dbphillips]

Have them look for a damaged harness...

 

[dbphillips]

To be a little more helpful (but not much ), someone mentioned a TSB in particular for chaffing at the alternator bracket, due to improper routing. I had a litany of crazy errors.

 

[SC2CO_TAHOE]

To be a little more helpful (but not much ), someone mentioned a TSB in particular for chaffing at the alternator bracket, due to improper routing. I had a litany of crazy errors.

Thx. I shared the TSB with the dealer and the visual wire inspection was ok. The dealer is working with GM on other potential causes and GM may recommend installation of a new engine wiring harness. It was in for a month and a half waiting for the crankshaft sensor I hope this goes quicker. I miss my Tahoe here in snowy CO the Malibu loaner isn’t up to the snow challenge.

 

[dbphillips]

Oof, that's an invasive repair. I would go over the harness in detail first. They could get the harness, get everything exposed, but not removed, then really inspect everything. I'd much rather have a patch, than count on everything getting routed correctly. The assembly people struggle enough with that, the mechanics are not suited to that kind of work.