97 4x4 5.9L dodge ram O2 sensor B1S2

[blaze2051]

i need your help, I have , 4 wire, 2x whites for elements and black/gray for signal. I been getting 0141 and 0138 which points to the downstream o2, and i replaced it and still getting hi volts b1s2. i checked the voltage on the truck side, and im getting 13v for the elements and 4v for the signal. my upstream sensor is working fine and no other CEL codes have returned its always 0138 and/or 0141.

truck has brand new fuel pump and remaned. bosch injectors
i checked the elements on the old and new o2 sensor im getting good resistance 5-7ohms
im might pull the old heat gun and see if the old and new o2 sensor can produce it own voltage

 

[Lubener]

Intake air temperature looks incorrect especially this time of the year. That sensor is in the intake duct and could be a separate sensor or incorporated into the MAF sensor.

 

[FowVay]

The codes state:
P0138: short-to-voltage, B1S2
P0141: O2 sensor heater failure

I'd start with the voltage check to the sensor as follows, This will verify power to the sensor:

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Here is a diagram of the sensor locations just to ensure you're checking the correct one and that the one you replaced was the correct one:

After you've checked for voltage to the correct sensor, start verifying continuity on the circuit.

Keep us posted!!

 

[blaze2051]

old and new B1S2 read good resistance 5-7ohms and both created their own voltage when heated up. I used a volt meter to get voltages reading on the truck side of connector 13v to elements and 4v to signal, Im going to use my power probe to retake readings on the truck side of connector.

 

[blaze2051]

old and new B1S2 read good resistance 5-7ohms and both created their own voltage when heated up. I used a volt meter to get voltages reading on the truck side of connector 13v to elements and 4v to signal, Im going to use my power probe to retake readings on the truck side of connector.

So I used the power probe and i got ground from all 3 wires with key on and 13v from the elements wire on the truck side, and ground from the 1 wire that is gray to the sensor. truck side wire that is orange w/black strip that goes to the black wire on the sensor had no reads I assume thats a ground wire but it would have to be for the voltage that the sensor creates since the other wire next to it is the gray wire and it had ground on the truck side.

Side note* would anyone know if the ASD Relay has anything to do with O2 B1S2 not working? Since i couldnt find a break in the wires on the truck side of connector.

 

[Mazomopar]

Sounds like you gave it a pretty good looking over but sons beast had similar issues.i followed the wiring harness up and over the tranny and found a rub/ wear spot way up on top where previous owner fixed(?) and zip ties things together.

 

[blaze2051]

Sounds like you gave it a pretty good looking over but sons beast had similar issues.i followed the wiring harness up and over the tranny and found a rub/ wear spot way up on top where previous owner fixed(?) and zip ties things together.

after i swapped the ASD relay with another relay it, B1S2 started working and the ecu was able to detect the voltage from the sensor, i dont know if the was the relay or it was my messing around with the wires on the truck side, but i never was able to find a break in the wires, truck is running great and smooth

 

[clinebarger]

So I used the power probe and i got ground from all 3 wires with key on and 13v from the elements wire on the truck side, and ground from the 1 wire that is gray to the sensor. truck side wire that is orange w/black strip that goes to the black wire on the sensor had no reads I assume thats a ground wire but it would have to be for the voltage that the sensor creates since the other wire next to it is the gray wire and it had ground on the truck side.

Side note* would anyone know if the ASD Relay has anything to do with O2 B1S2 not working? Since i couldnt find a break in the wires on the truck side of connector.

Orange with a Black tracer is the signal circuit.
Orange with a Green tracer is the 12vdc heater circuit from the ASD relay (Feeds both O2 sensors).
Black with a White tracer is the case ground for the O2 heater.
Black with a Light Blue tracer is the sensor ground/reference from the PCM.

Chrysler generally uses a 5vdc bias voltage on the signal circuit, As the sensor warms up, The voltage will be driven down to the normal 0-1vdc switching range.

As the heating element is not PCM controlled, The only way it has to run a diagnostic on the the O2 heater is to monitor how fast the bias voltage is driven low.

When you first start the engine (cold).....Both O2 sensor PID's should read close to 5vdc. High 4's usually, This is a good diagnostic tool for catch issues within the PCM.