Service Engine Soon

2001 PONTIAC 1000
75,000 MILES • 6 CYL • 2WD • AUTOMATIC
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LADYHAWKJJ
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My service engine soon light came on. I stopped at Auto Zone and this is it. Coolant temp is always low. The powertrain control module verifies that the engine is at a proper operating temperature. It was low on coolant and I put some in, however the light is still on. Am I supposed to reset it somehow. Or is there another problem. It did list some other possible causes.Thermostat defective, and ECI sensor defective. I drove the car 100 miles with the light on in one trip before I got the diagnostic, and the engine temp stayed below about 180. This is a 2001 Pontiac Grand Prix GT.
Nov 30, 2010 at 11:35 AM
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FIXITMR
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i'd try new thermostat.
Nov 30, 2010 at 11:55 AM
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WRENCHTECH
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What was the actual code number?
Nov 30, 2010 at 12:58 PM
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LADYHAWKJJ
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The Autozone paper says the OEM number to Cross is P0128. Does anyone know where the thermostat is on this vehicle so that I can check the wires? Also, I drove for about 30 minutes with the heater on, and it never got hot like it would normally. It was just a little warmer than tepid. Don't know if that helps.Thanks, Judy
Dec 1, 2010 at 12:12 AM
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WRENCHTECH
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Yes, a thermostat should fix that code. follow the upper radiator hose to the thermostat housing.
Dec 1, 2010 at 12:15 AM
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LADYHAWKJJ
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A new development. I went to change the thermostat, and when I pulled off the plastic engine cover, I discovered that while I was camping over the long weekend, rats got up under there and started a nest, and chewed on the wires.The light had initially come on on the way home from the camping trip. I put together and re-taped the wires. Pretty sure that was the problem. I started the car, but the service engine light is still on.I didn't run it long. Is there anyway to reset it? Or should I just drive it awhile and see if it goes out? One wire which was made of of fine copper wires was pretty chewed up. I could splice in a new piece if needed. I HATE RATS!!
Dec 2, 2010 at 10:33 PM
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WRENCHTECH
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I doubt rats set that code
Dec 2, 2010 at 11:05 PM
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LADYHAWKJJ
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No chance that the bared wires close to the thermostat could have caused the code? They could be the ones going to the ECI sensor or something. The timing is awful coincidental.
Dec 3, 2010 at 1:10 AM
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WRENCHTECH
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OK, fix it and find out.
Dec 3, 2010 at 1:15 AM
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LADYHAWKJJ
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OK, I replaced the thermostat. The Service Engine light is still on. Do I have to drive it awhile for it to reset, or should that have happened right away?
Dec 11, 2010 at 3:41 PM
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LADYHAWKJJ
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Also, I took off the positive battery cable for 15 minutes, not only did that not work, my radio stations were still there. Going to try again with both cables?..
Dec 11, 2010 at 4:32 PM
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LADYHAWKJJ
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Problem solved. Went back to Autozone and borrowed their code reader. Used it to erase the existing codes. Ran the car, and it hasn't come back on. Yeah!!!
Dec 11, 2010 at 8:19 PM
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FIXITMR
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so you have heat now?
Dec 11, 2010 at 8:19 PM
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LADYHAWKJJ
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Yes, my car is now toasty warm. Thanks...
Dec 15, 2010 at 10:24 PM
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WRENCHTECH
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Closing out question
Mar 28, 2011 at 6:56 PM