Hi folks. If you can help us with this, we'd certainly appreciate it. My
father is working on my sister's car and has encountered a problem he can't
quite diagnose. He describes it thusly:
2001 Chevy Malibu
3100 6 cyl engine
"Check Engine" light comes on when ignition is turned on and doesn't go off
until ignition is turned off. Temperature gauge in dash does not function.
Both cooling fans come on immediately after engine is started and do not
turn off until ignition is turned off. A test was performed for the "Check
Engine" light and an error code of P0128 was indicated.
Engine temperature sensor has been replaced and new coolant has been added.
Also, the battery was disconnected and reconnected. None of this has
helped. The thermostat is believed to be functioning properly as there is
no indication that engine is overheating.
When engine is started it idles at 800 rpms but when the wire to the
temperature sensor is disconnected, the rpms increase to 1200. There is no
indication that the engine is overheating.
When the ignition switch is turned on, there is no electric power to the 30
amp fuse in the box under the hood for cooling fan #2. Fuses in all 3 boxes
have been tested and are good.