Car is throwing heater circuit malfunction codes for all 02 sensors
04-14-2010, 08:50 AM
#1
Staging Lane
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Car is throwing heater circuit malfunction codes for all 02 sensors My car is throwing heater circuit malfunction codes for all 4 of my oxygen sensors. I know this is unlikely that they are all bad, and i checked the fuse for them and its not blown. Any other ideas?
04-15-2010, 02:09 PM
#4
Check the ground circuit. I believe all 4 sensors are on the same heater power and heater ground...if the fuse isn't blown, I'd bet that there is an issue with a broken wire somewhere in the loop after the fuse (broken and not shorted)...it might be before the sensors, or after them on the ground side.
07-13-2010, 01:49 PM
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ENG SEN fuse runs the heaters.
But you have to translate PCM-bitching into English.
It's complaining that things didn't start switching
soon enough, is all. That can be from straight heater
malfunction (fuse, wiring) or it can be from too much
thermal load for the sensor heaters to fight, or a jacked
mixture that won't switch the sensors in any case.
With all 4 out, look for a global problem (like fuse). But
if you have headers, this is all just par for the course
and you have to kill these codes (heater and insufficient
switching) and then live with the raggedy result of poor
sensor performance in closed loop.
But you have to translate PCM-bitching into English.
It's complaining that things didn't start switching
soon enough, is all. That can be from straight heater
malfunction (fuse, wiring) or it can be from too much
thermal load for the sensor heaters to fight, or a jacked
mixture that won't switch the sensors in any case.
With all 4 out, look for a global problem (like fuse). But
if you have headers, this is all just par for the course
and you have to kill these codes (heater and insufficient
switching) and then live with the raggedy result of poor
sensor performance in closed loop.
