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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Auto Service Tech
Category: Car
Satisfied Customers: 29496
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I start my car..check engine light..crank position battery

Resolved Question:

When I start my car sometime, the check engine light will stay on. It doesn't do it all the time. I had the car tuned, replaced the crank position sensor and put in a new battery. I also use 93 octane gas. What could caue this? (03 Saab Convertible)
Submitted: 6 years ago.
Category: Car
Expert:  GM Tech (Cam) replied 6 years ago.

Greetings and Welcome to Just answer.

What code is set? Can you get it scanned? Most part stores scan for free.

Customer: replied 6 years ago.
I don't have the code. According to the mechanic it was the code for the crank position sensor----this is the reason I replaced it.
Expert:  GM Tech (Cam) replied 6 years ago.

IF the code is for the sensor and a new sensor did not fix it then there is more than just the sensor wrong. IT could be a poor connection at the sensor or the engine module, it could be a bad wire, broken or chaffed somewhere.

Finally it could be the engine module itself.

I would check the terminals of the connectors for the engine module and the crank sensor. See if they are stretched, if not then check the wiring and see if there are any shorts to ground. Check that the crank sensor is seated properly. IF everything checks out then you likely need to replace the engine module.


Customer: replied 6 years ago.
One more thing----Code is P0340.
Expert:  GM Tech (Cam) replied 6 years ago.


THere are a couple of things that you can check. Anything that will cause a fuel mixture error or if this started after the spark plugs, that could be the issue.


GM Tech (Cam) and 3 other Car Specialists are ready to help you