C7 o2 censor hot voltage code
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,621
Likes: 4,068
From: Cape Coral, Florida
What DTC do you have ??…may be a bad sensor or the 12 volt heater circuit wire may be shorted to the signal wire…another member has this issue with his C7 right now.
P0158 and P2273 O2 sensor.code - CorvetteForum - Chevrolet Corvette Forum Discussion
P0158 and P2273 O2 sensor.code - CorvetteForum - Chevrolet Corvette Forum Discussion
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,621
Likes: 4,068
From: Cape Coral, Florida
Yep, seen that before. A high-voltage O₂ code usually means the sensor’s reading rich — could be extra fuel or the sensor itself going bad. Check for vacuum or exhaust leaks, and maybe clean the MAF just to rule that out.If you’ve got a scanner, watch the O₂ readings if it’s stuck high around 0.9V and not switching much, the sensor’s probably shot. What code are you getting, P0132 or something similar?
A “high voltage” DTC is usually not the car running rich or a MAF sensor…normally wiring or sensor.
Thread Starter
2nd Gear
Joined: Apr 2022
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what dtc do you have ??…may be a bad sensor or the 12 volt heater circuit wire may be shorted to the signal wire…another member has this issue with his c7 right now.
p0158 and p2273 o2 sensor.code - corvetteforum - chevrolet corvette forum discussion
p0158 and p2273 o2 sensor.code - corvetteforum - chevrolet corvette forum discussion
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,621
Likes: 4,068
From: Cape Coral, Florida
First thing it is always a good idea to let us know the model year...has any recent maintenance been done to the car ??...do you have any electrical experience and are you able to get underneath the car ??...if not find an automotive electrical shop in your area...if you can see what the millivolt reading is on bank 1 sensor 1 looking at live data on the car with the ignition ON...not ACC'Y...you should see 450Mv's which is a bias voltage...if you see above 1 volt remove Fuse 15 (Engine Inside Position) and then see what the reading is...that fuse is the power for the heater circuit of that O2 sensor...if it now reads lower the power wire may be shorted to the signal wire.
DTC P0131, P0132, P0137, P0138, P0151, P0152, P0157, or P0158
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle See: Vehicle > Initial Inspection and Diagnostic Overview > Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis See: Vehicle > Initial Inspection and Diagnostic Overview > Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions See: Vehicle > Initial Inspection and Diagnostic Overview > Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0131
- HO2S Circuit Low Voltage Bank 1 Sensor 1
DTC P0132
- HO2S Circuit High Voltage Bank 1 Sensor 1
DTC P0137
- HO2S Circuit Low Voltage Bank 1 Sensor 2
DTC P0138
- HO2S Circuit High Voltage Bank 1 Sensor 2
DTC P0151
- HO2S Circuit Low Voltage Bank 2 Sensor 1
DTC P0152
- HO2S Circuit High Voltage Bank 2 Sensor 1
DTC P0157
- HO2S Circuit Low Voltage Bank 2 Sensor 2
DTC P0158
- HO2S Circuit High Voltage Bank 2 Sensor 2
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.
Conditions for Running the DTC
P0131, P0137, P0151, or P0157
* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
* The ignition voltage is between 10-32 V.
* The fuel system is operating in Closed Loop.
* The fuel level is greater than 10%.
* Ethanol content is less than 87%.
* Decel fuel cut off is not active.
* The DTCs run continuously when the above conditions are met for 2 s.
P0132, P0138, P0152, or P0158
* DTCs P0030, P0031, P0032, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
* The ignition voltage is between 10-32 V.
* The oxygen sensor heater resistance has been learned.
* The fuel level is greater than 10%.
* Engine run time is greater than 5 s.
* The DTCs run continuously when the above conditions are met for 3 s.
Conditions for Setting the DTC
P0131, P0137, P0151, or P0157
* The engine control module detects that the heated oxygen sensor is shorted to ground if the HO2S voltage is less than 50 mV.
* The DTCs set within 6 s when the above condition is met.
P0132, P0138, P0152, or P0158
* The engine control module detects that the heated oxygen sensor has an open circuit or is shorted to voltage if the HO2S voltage is greater than 1,050 mV.
* The DTCs set within 13 s when the above condition is met.
Action Taken When the DTC Sets
DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0157 and P0158 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0157 and P0158 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics See: Powertrain Management > Electrical > Engine Controls Schematics
Connector End View Reference
Component Connector End Views See: Vehicle > Connector Views > Sunshade - Left
Electrical Information Reference
* Circuit Testing See: Vehicle > Component Tests and General Diagnostics > Circuit Testing
* Connector Repairs See: Vehicle > Component Tests and General Diagnostics > Connector Repairs
* Testing for Intermittent Conditions and Poor Connections See: Vehicle > Component Tests and General Diagnostics > Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs See: Vehicle > Component Tests and General Diagnostics > Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions > Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References See: Vehicle > Programming and Relearning > Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify no HO2S heater DTCs are set.
♦ If a DTC is set.
Refer to DTC P0030-P0032, P0036-P0038, P0050-P0054, P0056-P0060, P0135, P0141, P0155, or P0161 See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts > Powertrain Management.
♦ If a DTC is not set.
3. Engine running.
4. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameters are between 50-1,050 mV.
♦ If not between 50-1,050 mV.
Refer to Circuit/System Testing.
♦ If between 50-1,050 mV.
5. Operate the vehicle within the Conditions for Running. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
6. Verify the DTC does not set.
♦ If the DTC sets.
Refer to Circuit/System Testing.
♦ If the DTC does not set.
7. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate B52 Heated Oxygen Sensor harness connector. It may take up to 2 minutes for all vehicle systems to power down. Ignition ON.
2. Test for 1.7-3.0 V between the high signal circuit terminal 4 and ground.
♦ If less than 1.7 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the high signal circuit and ground.
♦ If less than infinite resistance, repair the short to ground on the circuit.
♦ If infinite resistance
3. Test for less than 2 ohms in the high signal circuit end to end.
♦ If 2 ohms or greater, repair the open/high resistance in the circuit.
♦ If less than 2 ohms, replace the K20 Engine Control Module.
♦ If greater than 3.0 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON.
2. Test for less than 1 V between the high signal circuit and ground.
♦ If 1 V or greater, repair the short to voltage on the circuit.
♦ If less than 1 V, replace the K20 Engine Control Module.
♦ If between 1.7-3.0 V
3. Verify the scan tool heated oxygen sensor Bank 1 or 2 Sensor 1 or 2 parameter is between 1.7-2.1 V.
♦ If less than 1.7 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the low signal circuit terminal 3 and ground.
♦ If less than infinite resistance, repair the short to ground on the circuit.
♦ If infinite resistance, replace the K20 Engine Control Module.
♦ If between 1.7-2.1 V
4. Connect a 3 A fused jumper wire between the high signal circuit terminal 4 and the low signal circuit terminal 3.
Note: The low signal circuit is tied to a pull-up circuit within the engine control module. A voltage of 0.0-1.10 V on the low signal circuit is normal.
5. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameter displays 0.0 V.
♦ If greater than 0.0 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON.
2. Test for less than 2 ohms in the low signal circuit end to end.
♦ If 2 ohms or greater, repair the open/high resistance in the circuit.
♦ If less than 2 ohms
3. Test for less than 1 V between the low signal circuit terminal 3 and ground.
♦ If 1 V or greater, repair the short to voltage on the circuit.
♦ If less than 1 V, replace the K20 Engine Control Module.
♦ If 0.0 V
6. Verify none of the conditions listed below exist:
* Water intrusion in the B52 heated oxygen sensor harness connector
* Low or high fuel system pressure-Refer to Fuel System Diagnosis See: Fuel Delivery and Air Induction > Component Tests and General Diagnostics > Fuel System Diagnosis.
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis See: Fuel > Component Tests and General Diagnostics > Alcohol/Contaminants-in-Fuel Diagnosis.
* Fuel saturation of the evaporative emission (EVAP) canister
* Exhaust leaks
* Engine vacuum leaks
♦ If any of the conditions exist
Repair as necessary.
♦ If none of the conditions exist
7. Test or replace the B52 Heated Oxygen Sensor.
DTC P0131, P0132, P0137, P0138, P0151, P0152, P0157, or P0158
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle See: Vehicle > Initial Inspection and Diagnostic Overview > Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis See: Vehicle > Initial Inspection and Diagnostic Overview > Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions See: Vehicle > Initial Inspection and Diagnostic Overview > Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0131
- HO2S Circuit Low Voltage Bank 1 Sensor 1
DTC P0132
- HO2S Circuit High Voltage Bank 1 Sensor 1
DTC P0137
- HO2S Circuit Low Voltage Bank 1 Sensor 2
DTC P0138
- HO2S Circuit High Voltage Bank 1 Sensor 2
DTC P0151
- HO2S Circuit Low Voltage Bank 2 Sensor 1
DTC P0152
- HO2S Circuit High Voltage Bank 2 Sensor 1
DTC P0157
- HO2S Circuit Low Voltage Bank 2 Sensor 2
DTC P0158
- HO2S Circuit High Voltage Bank 2 Sensor 2
Diagnostic Fault Information
Typical Scan Tool Data
Circuit/System Description
The heated oxygen sensors (HO2S) are used for fuel control and catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content of the exhaust stream. When the engine is started, the control module operates in an Open Loop mode, ignoring the HO2S signal voltage while calculating the air-to-fuel ratio. While the engine runs, the HO2S heats up and begins to generate a voltage within a range of 0-1,000 mV. Once sufficient HO2S voltage fluctuation is observed by the control module, Closed Loop is entered. The control module uses the HO2S voltage to determine the air-to-fuel ratio. An HO2S voltage that increases toward 1,000 mV indicates a rich fuel mixture. An HO2S voltage that decreases toward 0 mV indicates a lean fuel mixture.
The heating elements inside each HO2S heat the sensor to bring the sensor up to operating conditions faster. This allows the system to enter Closed Loop earlier and the control module to calculate the air-to-fuel ratio sooner.
Conditions for Running the DTC
P0131, P0137, P0151, or P0157
* DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
* The ignition voltage is between 10-32 V.
* The fuel system is operating in Closed Loop.
* The fuel level is greater than 10%.
* Ethanol content is less than 87%.
* Decel fuel cut off is not active.
* The DTCs run continuously when the above conditions are met for 2 s.
P0132, P0138, P0152, or P0158
* DTCs P0030, P0031, P0032, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0205, P0206, P0207, P0208, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
* The ignition voltage is between 10-32 V.
* The oxygen sensor heater resistance has been learned.
* The fuel level is greater than 10%.
* Engine run time is greater than 5 s.
* The DTCs run continuously when the above conditions are met for 3 s.
Conditions for Setting the DTC
P0131, P0137, P0151, or P0157
* The engine control module detects that the heated oxygen sensor is shorted to ground if the HO2S voltage is less than 50 mV.
* The DTCs set within 6 s when the above condition is met.
P0132, P0138, P0152, or P0158
* The engine control module detects that the heated oxygen sensor has an open circuit or is shorted to voltage if the HO2S voltage is greater than 1,050 mV.
* The DTCs set within 13 s when the above condition is met.
Action Taken When the DTC Sets
DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0157 and P0158 are Type B DTCs.
Conditions for Clearing the MIL/DTC
DTCs P0131, P0132, P0137, P0138, P0151, P0152, P0157 and P0158 are Type B DTCs.
Reference Information
Schematic Reference
Engine Controls Schematics See: Powertrain Management > Electrical > Engine Controls Schematics
Connector End View Reference
Component Connector End Views See: Vehicle > Connector Views > Sunshade - Left
Electrical Information Reference
* Circuit Testing See: Vehicle > Component Tests and General Diagnostics > Circuit Testing
* Connector Repairs See: Vehicle > Component Tests and General Diagnostics > Connector Repairs
* Testing for Intermittent Conditions and Poor Connections See: Vehicle > Component Tests and General Diagnostics > Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs See: Vehicle > Component Tests and General Diagnostics > Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions See: A L L Diagnostic Trouble Codes ( DTC ) > Diagnostic Trouble Code Descriptions > Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References See: Vehicle > Programming and Relearning > Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Verify no HO2S heater DTCs are set.
♦ If a DTC is set.
Refer to DTC P0030-P0032, P0036-P0038, P0050-P0054, P0056-P0060, P0135, P0141, P0155, or P0161 See: A L L Diagnostic Trouble Codes ( DTC ) > P Code Charts > Powertrain Management.
♦ If a DTC is not set.
3. Engine running.
4. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameters are between 50-1,050 mV.
♦ If not between 50-1,050 mV.
Refer to Circuit/System Testing.
♦ If between 50-1,050 mV.
5. Operate the vehicle within the Conditions for Running. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
6. Verify the DTC does not set.
♦ If the DTC sets.
Refer to Circuit/System Testing.
♦ If the DTC does not set.
7. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the appropriate B52 Heated Oxygen Sensor harness connector. It may take up to 2 minutes for all vehicle systems to power down. Ignition ON.
2. Test for 1.7-3.0 V between the high signal circuit terminal 4 and ground.
♦ If less than 1.7 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the high signal circuit and ground.
♦ If less than infinite resistance, repair the short to ground on the circuit.
♦ If infinite resistance
3. Test for less than 2 ohms in the high signal circuit end to end.
♦ If 2 ohms or greater, repair the open/high resistance in the circuit.
♦ If less than 2 ohms, replace the K20 Engine Control Module.
♦ If greater than 3.0 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON.
2. Test for less than 1 V between the high signal circuit and ground.
♦ If 1 V or greater, repair the short to voltage on the circuit.
♦ If less than 1 V, replace the K20 Engine Control Module.
♦ If between 1.7-3.0 V
3. Verify the scan tool heated oxygen sensor Bank 1 or 2 Sensor 1 or 2 parameter is between 1.7-2.1 V.
♦ If less than 1.7 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the low signal circuit terminal 3 and ground.
♦ If less than infinite resistance, repair the short to ground on the circuit.
♦ If infinite resistance, replace the K20 Engine Control Module.
♦ If between 1.7-2.1 V
4. Connect a 3 A fused jumper wire between the high signal circuit terminal 4 and the low signal circuit terminal 3.
Note: The low signal circuit is tied to a pull-up circuit within the engine control module. A voltage of 0.0-1.10 V on the low signal circuit is normal.
5. Verify the scan tool HO2S Bank 1 or 2 Sensor 1 or 2 parameter displays 0.0 V.
♦ If greater than 0.0 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module. Ignition ON.
2. Test for less than 2 ohms in the low signal circuit end to end.
♦ If 2 ohms or greater, repair the open/high resistance in the circuit.
♦ If less than 2 ohms
3. Test for less than 1 V between the low signal circuit terminal 3 and ground.
♦ If 1 V or greater, repair the short to voltage on the circuit.
♦ If less than 1 V, replace the K20 Engine Control Module.
♦ If 0.0 V
6. Verify none of the conditions listed below exist:
* Water intrusion in the B52 heated oxygen sensor harness connector
* Low or high fuel system pressure-Refer to Fuel System Diagnosis See: Fuel Delivery and Air Induction > Component Tests and General Diagnostics > Fuel System Diagnosis.
* Fuel that is contaminated-Refer to Alcohol/Contaminants-in-Fuel Diagnosis See: Fuel > Component Tests and General Diagnostics > Alcohol/Contaminants-in-Fuel Diagnosis.
* Fuel saturation of the evaporative emission (EVAP) canister
* Exhaust leaks
* Engine vacuum leaks
♦ If any of the conditions exist
Repair as necessary.
♦ If none of the conditions exist
7. Test or replace the B52 Heated Oxygen Sensor.
Last edited by C5 Diag; Oct 16, 2025 at 08:48 AM.
