O2 P0141 & P0161 faults
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Joined: Mar 2005
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From: Spring, Texas
O2 P0141 & P0161 faults
I have a 2001 4.7L Quad Dakota. My error codes are P0141 & P0161, O2 heater sensor circuit malfunction. The sensors have 4 wires:Blue-O2 signal, White-ground, Black1-12VDC, and Black2-heater. I pulled the sensor plug and found ground and 12VDC, but the heater line is shorted to ground (without the sensor plugged in). I read an explanation that the 141 & 161 codes mean that the heater circuit is drawing more then 2.25A, which I could believe if the heater line is shorted upstream of the sensor. When I attempt to read the resistance of the sensor heater (black to black) it appears open. Does this make sense? If the harness is shorted, I'd hate to blow $250 on two new sensors and burn them out. Does anyone have any ideas????? The truck won't pass inspection with the faults.
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Joined: May 2004
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From: St. Louis, Missouri
RE: O2 P0141 & P0161 faults
Looks by your description that you should be checking resistance between White-Ground and Black2-Heater on the sensor connector to check the heater itself.
They are not always that simple. I know for a fact that GM sensors cannot be tested this way because they are PWM heaters. Same thing, a 4 wire setup, but the 12V in and ground aren't simply just both legs of the heater resistor. The third heater wire sends a PWM signal to determine the amount of resistance that the heater resistor should produce.
It sounds like you have your hands on a service manual, follow the trouble tree.
They are not always that simple. I know for a fact that GM sensors cannot be tested this way because they are PWM heaters. Same thing, a 4 wire setup, but the 12V in and ground aren't simply just both legs of the heater resistor. The third heater wire sends a PWM signal to determine the amount of resistance that the heater resistor should produce.
It sounds like you have your hands on a service manual, follow the trouble tree.
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Registered User
Joined: Mar 2005
Posts: 9
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From: Spring, Texas
RE: O2 P0141 & P0161 faults
Actually I don't have a manual...seems as though no one has made one. I have been researching the O2 sensors online through various articles. I read that the heater draws 1.5A when cold then drops to 100mA when at operating temps. I will check the current draw-I guess that would be the best indictor of whether or not the sensor heater is good. If the heater is open, there should be no current flow. I still find it odd that with the sensor removed, the heater line is shorted to ground in the harness.
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Joined: May 2004
Posts: 1,115
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From: St. Louis, Missouri
RE: O2 P0141 & P0161 faults
The best Manual in the World for your truck can be purchased here.......1-800-890-4038.
Your manual # is 81-370-1010 for the AN Dakota.
Don't know about price and this is too early of a model for me to provide you with a copy on CD. Mine is paper.
Your manual # is 81-370-1010 for the AN Dakota.
Don't know about price and this is too early of a model for me to provide you with a copy on CD. Mine is paper.
