Buick Regal: DTC P0030-P0032, P0036-P0038, P0054, P0135, P0141, P103B, or P103C

Diagnostic Instructions

• Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle
• Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis
• An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions

DTC Descriptor

DTC P0030

HO2S Heater Control Circuit Sensor 1

DTC P0031

HO2S Heater Control Circuit Low Voltage Sensor 1

DTC P0032

HO2S Heater Control Circuit High Voltage Sensor 1

DTC P0036

HO2S Heater Control Circuit Sensor 2

DTC P0037

HO2S Heater Control Circuit Low Voltage Sensor 2

DTC P0038

HO2S Heater Control Circuit High Voltage Sensor 2

DTC P0054

HO2S Heater Resistance Sensor 2

DTC P0135

HO2S Heater Performance Sensor 1

DTC P0141

HO2S Heater Performance Sensor 2

DTC P103B

HO2S Heater Supply Voltage Sensing Circuit Performance

DTC P103C

HO2S Heater Supply Voltage Sensing Circuit Low Voltage

Diagnostic Fault Information

Circuit/System Description

Conditions for Running the DTC

P0030, P0031, P0032, P0036, P0037, P0038

• Engine Speed=Greater than 400 RPM
• Ignition Voltage=11 to 32 V

Frequency the DTC runs=Continuously - After the running conditions are met - For greater than 5 s

P0053

• DTCs related to the following system/component = Not Set
  • B34 Engine Coolant Temperature Sensor
  • B111B Turbocharger Boost/Intake Air Temperature Sensor
• ECT Sensor & IAT Sensor=Within 8ºC (14ºF) of each other
• ECT Sensor=30 to 255ºC (86 to 491ºF)
• Engine=Running
• Ignition Voltage=Less than 32 V

Frequency the DTC runs=Once - Per cold start-up - After the running conditions are met

P0135, P0141

• DTC P0116, P0117, P0118, P0119, P0128, P111E = Not set
• HO2S Heater=Device controls are not active.
• HO2S 1, 2 Heater Command=Greater than 0% Duty Cycle
• Ignition Voltage=10 to 32 V

Frequency the DTC runs=2 times - Per drive cycle - After the running conditions are met - For greater than 120 s

P103B, P103C

• Engine= Cranking or Running
• Ignition Voltage=10 to 32 V

Frequency the DTC runs=Continuously - After the running conditions are met - For greater than 3 s

Conditions for Setting the DTC

P0030, P0031, P0032, P0036, P0037, P0038

Control Circuit=Commanded state does not match the actual state - For greater than 5 s

P0053, P0054

HO2S Heater Resistance=Resistance Out Of Range - During engine startup

P0135, P0141

HO2S 1, 2 Heater 0.3 to 2.5 A - For greater than 10 s

P103B

HO2S Heater Supply Voltage & Ignition Voltage=Not within 2 V of each other - For greater than 3 s

P103C

HO2S Heater Supply Voltage=Less than 6 V - For greater than 3 s

Actions Taken When the DTC Sets

DTCs listed in the DTC Descriptor Category=Type B DTC

Conditions for Clearing the DTC

DTCs listed in the DTC Descriptor Category=Type B DTC

Diagnostic Aids

High resistance in the circuits of the component may set DTC P103B, P103C without setting the DTC for the component: B52 Heated Oxygen Sensor

Reference Information

Schematic Reference

Engine Controls Wiring Schematics (LTG)

Connector End View Reference

Component Connector End View Index

Electrical Information Reference

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References

Circuit/System Verification

1. Engine - Idling - At normal operating temperature

NOTE: This step only applies to the following component DTCs: HO2S Heater.

2. Verify DTC P103B, P103C is not set and no other DTCs are set.

• If DTC P103B, P103C is set and other DTCs are set
• If DTC P103B, P103C is not set and other DTCs are set
• If DTC P103B, P103C is set and no other DTCs are set
• Go to next step: If no DTC is set

3. Verify the scan tool parameter:

• HO2S 1, 2 Heater Control Circuit High Voltage Test Status= OK or Not Run
• HO2S 1, 2 Heater Control Circuit Low Voltage Test Status= OK or Not Run
• HO2S 1, 2 Heater Control Circuit Open Test Status= OK or Not Run
• If not the specified state
• Go to next step: If the specified state

4. Verify the scan tool parameter:

HO2S 1, 2 Heater=0.3 to 2.4 A

• If not between 0.3 and 2.4 A
• Go to next step: If between 0.3 and 2.4 A

5. Verify the scan tool parameter: HO2S 1, 2 Heater=The value should not spike or drop out.

Perform the action while monitoring the parameter:

• Wiggle the harness and connector: B52 Heated Oxygen Sensor
• Wiggle the harness and connector: K20 Engine Control Module
• If the value spikes or drops out

Repair as necessary - Wiring / Terminal (s) / Electrical Connector (s)

• Go to next step: If the value does not spike or drop out

6. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Verify the DTC does not set.

• If the DTC sets

Refer to step 2

• Go to next step: If the DTC is not set

7. All OK.

Circuit/System Testing

Test 1

1. Ignition/Vehicle & All vehicle systems - Off.

2. Disconnect the appropriate electrical connector: B52 Heated Oxygen Sensor.

3. Ignition - On / Vehicle - In Service Mode.

4. Verify a test lamp turns On between the test points:

• {B52A Heated Oxygen Sensor 1}Ignition circuit terminal 5 & Ground
• {B52B Heated Oxygen Sensor 2}Ignition circuit terminal 2 & Ground
• If the test lamp does not turn On and the circuit fuse is OK

1. Ignition/Vehicle - Off & Remove - Test lamp
2. Test for less than 2 ohms between the test points:
   • {B52A Heated Oxygen Sensor 1}Ignition circuit terminal 5 & Output terminal@Fuse
   • {B52B Heated Oxygen Sensor 2}Ignition circuit terminal 2 & Output terminal@Fuse
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.

• If the test lamp does not turn On and the circuit fuse is open

1. Ignition/Vehicle - Off & Remove - Test lamp
2. Connect the electrical connector: B52 Heated Oxygen Sensor
3. Ignition - On / Vehicle - In Service Mode
4. Replace the component: Fuse
5. Verify the fuse does not open.
   • If the fuse opens and there are components connected to the circuit - Disconnect a component and repeat step 4.4
   • If the fuse opens with all components disconnected from the circuit - Repair the short to ground on the circuit.
   • If the fuse does not open after disconnecting a component from the circuit - Replace the component disconnected last.
   • Go to next step: If the fuse does not open with all components connected.

NOTE: It may be necessary to use a scan tool control function to operate a component.

6. Operate the component: Each component on the circuit - One at a time

Verify the fuse does not open when any of the components are activated.

• If the fuse opens - Replace the component that caused the fuse to open when activated.
• Go to next step: If the fuse does not open.

7. All OK.

• Go to next step: If the test lamp turns On

5. Verify a test lamp does not turn On between the test points:

• {B52A Heated Oxygen Sensor 1}Ignition circuit terminal 5 & Control circuit terminal 6
• {B52B Heated Oxygen Sensor 2}Ignition circuit terminal 2 & Control circuit terminal 1
• If the test lamp turns On

1. Ignition/Vehicle - Off & Remove - Test lamp
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for infinite resistance between the test points:
   • {B52A Heated Oxygen Sensor 1}Control circuit terminal 6@Component harness & Ground
   • {B52B Heated Oxygen Sensor 2}Control circuit terminal 1@Component harness & Ground
   • If less than infinite resistance - Repair the short to ground on the circuit.
   • If infinite resistance - Replace the component: K20 Engine Control Module

• Go to next step: If the test lamp does not turn On

6. Remove - Test Lamp.

7. Engine - Running.

8. Verify the scan tool parameter: HO2S 1, 2 Heater Control Circuit Open Test Status=Malfunction.

• If not the specified state

1. Ignition/Vehicle - Off
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Ignition - On / Vehicle - In Service Mode
4. Test for less than 1 V between the test points:
   • {B52A Heated Oxygen Sensor 1}Control circuit terminal 6@Component harness & Ground
   • {B52B Heated Oxygen Sensor 2}Control circuit terminal 1@Component harness & Ground
   • If 1 V or greater - Repair the short to voltage on the circuit.
   • If less than 1 V - Replace the component: K20 Engine Control Module

• Go to next step: If the specified value

NOTE:

• As little as 10 ohms of resistance in a circuit may cause a DTC to set.
• Performing this test may set additional DTCs.

9. Connect a 3 A fused jumper wire between the test points:

• {B52A Heated Oxygen Sensor 1}Ignition circuit terminal 5 & Control circuit terminal 6
• {B52B Heated Oxygen Sensor 2}Ignition circuit terminal 2 & Control circuit terminal 1

10. Engine - Running

11. Verify the scan tool parameter: HO2S 1, 2 Heater Control Circuit High Voltage Test Status =Malfunction

• If not the specified state

1. Ignition/Vehicle - Off & Remove - Jumper wire (s)
2. Disconnect the appropriate electrical connector: K20 Engine Control Module
3. Test for less than 2 ohms between the test points:
   • {B52A Heated Oxygen Sensor 1}Control circuit terminal 6@Component harness & The other end of the circuit@Control module harness
   • {B52B Heated Oxygen Sensor 2}Control circuit terminal 1@Component harness & The other end of the circuit@Control module harness
   • If 2 ohms or greater - Repair the open/high resistance in the circuit.
   • If less than 2 ohms - Replace the component: K20 Engine Control Module

• Go to next step: If the specified state

12. Test or replace the component: B52 Heated Oxygen Sensor

Test 2

1. Ignition/Vehicle - Off.

2. Disconnect the appropriate electrical connector: K20 Engine Control Module.

3. Test for less than 2 ohms between the test points: Output terminal@Fuse & The other end of the circuit@Control module harness.

• If 2 ohms or greater

Repair the open/high resistance in the circuit:

• Go to next step: If less than 2 ohms

4. Replace the component: K20 Engine Control Module

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification

• Heated Oxygen Sensor Replacement - Sensor 1
• Heated Oxygen Sensor Replacement - Sensor 2
• For control module replacement, programming, and setup refer to: Control Module References

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