Expert: Roland Finston - 9/7/2011

Question
please help . i have a 2005 chrysler pacifica found code p0132 . and replace front O2 sensor . and clear the code and start the car . engine light off and running for two hour with no problem. after that let the car cool off and restart it . the engine light is on . code p0132, p0032 . data reading on 1/1 O2s(v) 3.27 v when hot. but the heater reading is  
1/1 O2 HTR DC(%)------ 0.
and i check all the wiring they are good.
can you please let me know what should i do next . thank you

Answer
Hi Ken,
I assume you have been dealing with the right side upstream sensor (right side as the engine would view, e.g. toward the firewall). There are only four wires so it isn't that complex:
The black/light green on pin 1 should show continuity to ground, the brown/tan on pin 2 should show 12V, the wires on pins 3 and 4 are for the signal to be measured and those should show continuity to pins show continuity to pins 32 brown/dark green and 31 dark blue/light blue, respectively, at the black/orange plug of the pcm, and have no significant voltage showing on either one compared to ground with the plug disconnected from the sensor. The voltage between those two wires when the engine is hot and running should be around 1/2 volt. I am not clear what voltages you were measuring were so please reference those to the pins/wires I have listed. Either there is 12v shorting over to the signal wire, or one of the signal wires is open, or something of that sort. Compare the situation to what you find on the left side sensor would be another way to pinpoint the problem. The pins of the 2 plug are identically assigned on the two sides, but not the wire colors nor the pins at the pcm that wires go to. The resistance across the sensor heater pins (1 and 2) should be about 2 ohms. So let me know what is different between what you measure on one plug as compared to the other plug when the plugs are removed from their sensors.
Roland