P0052
P0052 - O2 Sensor 2/1 Heater Circuit High
For wiring diagrams, refer to.
• When Monitored: With the engine running and battery voltage greater than 10 volts.
• Set Condition: The PCM detects that the 2/1 oxygen sensor control circuit voltage is more than the maximum acceptable value.
• Always perform the pre-diagnostic troubleshooting procedure before proceeding. Refer to => Non-DTC Based Diagnostics. Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - DTC is Active
• Start the engine and allow it to reach normal operating temperature.
When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
• With the scan tool, select view DTCs.
Is the status Active for this DTC?
Yes
• Go to Test Step 2 => [ Test
Step 2 - Ground Circuit Open or High Resistance ]
No
• Refer to the checking for an intermittent DTC diagnostic procedure. Refer => Non-DTC Based Diagnostics.
Test Step 2 - Ground Circuit Open or High Resistance
• Turn the ignition OFF.
• Disconnect the 2/1 oxygen sensor connector.
• Using a test lamp connected to 12 volts, check the ground circuit in the harness connector.
• The test lamp should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test lamp illuminated and bright?
Yes
• Go to Test Step 3 => [ Test
Step 3 - O2S 2/1 Heater Control Circuit Shorted to Voltage ]
No
• Repair the ground circuit for an open or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 3 - O2S 2/1 Heater Control Circuit Shorted to Voltage
• Turn the ignition OFF.
• Disconnect the PCM.
• Turn the ignition ON.
• Measure the voltage of the O2S 2/1 heater control circuit in the harness connector.
Is there any voltage present?
Yes
• Repair the circuit for a short to voltage.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Go to Test Step 4 => [ Test
Step 4 - O2S 2/1 Heater Control Circuit Open or High Resistance ]
Test Step 4 - O2S 2/1 Heater Control Circuit Open or High Resistance
• Turn the ignition OFF.
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals, resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.
• Measure the resistance of the O2S 2/1 heater control circuit between the harness connector and the appropriate terminal of special tool #8815.
Is the resistance less than 5.0 ohms?
Yes
• Go to Test Step 5 => [ Test
Step 5 - 2/1 Oxygen Sensor Control Actuation ]
No
• Repair the circuit for an open or high resistance.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 5 - 2/1 Oxygen Sensor Control Actuation
• Connect the PCM connector.
• Turn the ignition ON.
• With the scan tool, actuate the 2/1 oxygen sensor control to the ON (maximum) position.
• Using a test lamp connected to ground, check the O2S 2/1 heater control circuit in the harness connector.
• The test lamp should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.
• With the scan tool, actuate the 2/1 oxygen sensor control to OFF (0%).
• Using a test lamp connected to ground, check the O2 2/1 heater control circuit in the harness connector.
• The test lamp should not be illuminated with the control actuated OFF (0%).
Is the test lamp illuminated when actuated ON and not illuminated when actuated OFF as described?
Yes
• Go to Test Step 6 => [ Test
Step 6 - 2/1 Oxygen Sensor ]
No
• Go to Test Step 7 => [ Test
Step 7 - PCM ]
Test Step 6 - 2/1 Oxygen Sensor
• Turn the ignition OFF.
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/1 oxygen sensor and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace the 2/1 oxygen sensor.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
Test Step 7 - PCM
• Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the 2/1 oxygen sensor and the PCM.
• Look for any chafed, pierced, pinched, or partially broken wires.
• Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.
• Refer to any technical service bulletins that may apply.
Were any problems found?
Yes
• Repair as necessary.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test
No
• Replace and program the PCM.
• Perform the PCM Verification Test. Refer to => Non-DTC
Based Diagnostics. PCM Verification Test