Sensor issues, need your help.
06-08-2011, 11:21 AM
#1
Sensor issues, need your help.
Whats up guys...had my HFCs installed a few days ago but i have a check engine light on.....the code is P0051. Its not from the HFCs but apparently some kind of heater or whatever....what do you think its from?
06-08-2011, 11:30 AM
#2
P0051 Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1) - DTC Code
CopyPasta from 1st Google hit:
P0051 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
OBD-II Trouble Code Technical Description
Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
What does that mean?
A P0051 DTC (diagnostic trouble code) refers to the O2 sensor (oxygen sensor) located on Bank 2 in front of the catalytic converter. There is also an oxygen sensor behind the converter which is Sensor #2.
This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles it is. It detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle's computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the A/F O2 sensor. Essentially this P0051 code means that the resistance of the heater circuit is lower than normal. In most cases, that resistance level must fall below 0.8 A to trigger the DTC code.
Note, this code is very similar in nature to P0031, P0032, and P0052
Potential Symptoms
Most likely you'll not notice any symptoms other than the MIL (malfunction indicator lamp, a.k.a. the check engine light) will illuminate.
Causes
A P0051 DTC trouble code may be caused by one or more of the following:
A short in the heater circuit in the sensor
A failed O2 sensor heater
Wiring/connectors broken/frayed leading to sensor and/or relay
Failed PCM/ECM
Possible Solutions
To fix a P0051 DTC code, you'll need to do a proper diagnosis. To do that, you'll want to inspect the wiring and connectors leading to the sensor. Also if equipped with a heater relay and fuse, you'll want to check those as well. Use a digital volt ohm meter to:
check for 12 volts at the heater circuit feed (hint: unplug the sensor and check at the wiring connector to do this measurement)
check the ground circuit for continuity
measure the resistance of the heater circuit (done on the sensor itself)
measure the resistance and voltage of the wiring
Refer to a service manual for the correct specifications (volts, ohms) for your vehicle. On some Toyota vehicles this code is triggered when the resistance of the heater circuit is below 0.8 A.
With that said, a common fix for this DTC is to replace the air/fuel (O2 oxygen) sensor #1 on bank 2 (the side of the engine that doesn't contain cylinder #1).
CopyPasta from 1st Google hit:
P0051 - Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
OBD-II Trouble Code Technical Description
Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 2 Sensor 1)
What does that mean?
A P0051 DTC (diagnostic trouble code) refers to the O2 sensor (oxygen sensor) located on Bank 2 in front of the catalytic converter. There is also an oxygen sensor behind the converter which is Sensor #2.
This O2 sensor #1 may also be refered to as an air/fuel ratio sensor since on some vehicles it is. It detects the amount of oxygen in the exhaust gas compared to the outside air and then vehicle's computer adjusts the air/fuel ratio going into the engine. The sensor is less effective when the exhaust gas temperature is low, so it includes a heater which is activated to help get better readings from the A/F O2 sensor. Essentially this P0051 code means that the resistance of the heater circuit is lower than normal. In most cases, that resistance level must fall below 0.8 A to trigger the DTC code.
Note, this code is very similar in nature to P0031, P0032, and P0052
Potential Symptoms
Most likely you'll not notice any symptoms other than the MIL (malfunction indicator lamp, a.k.a. the check engine light) will illuminate.
Causes
A P0051 DTC trouble code may be caused by one or more of the following:
A short in the heater circuit in the sensor
A failed O2 sensor heater
Wiring/connectors broken/frayed leading to sensor and/or relay
Failed PCM/ECM
Possible Solutions
To fix a P0051 DTC code, you'll need to do a proper diagnosis. To do that, you'll want to inspect the wiring and connectors leading to the sensor. Also if equipped with a heater relay and fuse, you'll want to check those as well. Use a digital volt ohm meter to:
check for 12 volts at the heater circuit feed (hint: unplug the sensor and check at the wiring connector to do this measurement)
check the ground circuit for continuity
measure the resistance of the heater circuit (done on the sensor itself)
measure the resistance and voltage of the wiring
Refer to a service manual for the correct specifications (volts, ohms) for your vehicle. On some Toyota vehicles this code is triggered when the resistance of the heater circuit is below 0.8 A.
With that said, a common fix for this DTC is to replace the air/fuel (O2 oxygen) sensor #1 on bank 2 (the side of the engine that doesn't contain cylinder #1).
06-08-2011, 10:26 PM
#4
Hey SRG you probably already saw the thread but it looks like another guy is having the same issues with the same HFC...weird huh?
https://www.myg37.com/forums/g37-cou...o2-sensor.html
https://www.myg37.com/forums/g37-cou...o2-sensor.html
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