TROUBLE CODES: P0640, P0650, P0670

  • Tiny
  • 95buick95
  • 1995 Buick Lesabre
  • 85,000 miles

I'm getting all 3 of these codes and not sure what to do.

I had been getting a P0171 code and I cleaned the mass air flow sensor.

This seemed to solve the P0171 problem and it also stopped the valves from pinging.

Car ran great for two days and still seems to be running fine but the check engine light is coming back on now and my scan tool is giving me these 3 codes: P640-QDM 1 FAULT, P650-QDM 2 FAULT, and P670-QDM 4 FAULT.

Can you please help me with this?

Wednesday, April 25th, 2012 AT 12:49 AM

3 Answers

  • Tiny
  • ASEMaster6371
  • Expert
  • 25,502 posts

You need to check the injector readings. Do an ohm check on them to make sure they are ok. You may also have a bad pcm but you need to have it verified by a shop before spending any money.

Roy

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Wednesday, April 25th, 2012 AT 12:54 AM
  • Tiny
  • 95buick95
  • Member

Thanks for the response ASEMaster. Could you please give me the specifics on testing the injectors? Also, if the injectors turn out to be ok, would you lean toward the computer being bad?

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Wednesday, April 25th, 2012 AT 1:03 AM
  • Tiny
  • ASEMaster6371
  • Expert
  • 25,502 posts

The ohms should be about 7-9 ohms. If any or if all are the same, then all is good on them. If they are varying more than 2 or 3 ohms, it may be time for new injectors.

Roy

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Wednesday, April 25th, 2012 AT 1:15 AM

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