Mechanics

CHEVY FAULT CODE PO128

2002 Chevrolet Impala

Engine Cooling problem
2002 Chevy Impala 6 cyl Front Wheel Drive Automatic 73000 miles

PO128 appeared on my car while driving down the highway. I cleared the code with my MemoScanner (no freeze codes) and have driven the car 2-300 miles without any code coming on. Yesterday I drove the car on a 100 mile trip and checked the coolant operating temperature with my scanner and it was 88Celsius/190F. It indicates cool but it appears it's running at normal operating temperature. Does this mean the temperature sensor is bad?

Thanks, OMB
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Ombena
December 7, 2009.




Either the coolant temp sensor or the thermostat.

Chevy has had some problems with the temp sensor, especially on the inline 6 with the temp sensor malfunctioning.

Mmprince4000
Dec 11, 2009.


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