Page 919 of 5267

3.(K343) FUSED ASD RELAY OUTPUT CIRCUIT OPEN
Ignition on, engine not running.
With the scan tool, actuate the O2 Heater Test.
Using a 12-volt test light connected to ground, probe the (K343) Fused
ASD Relay Output circuit at the O2 Sensor harness connector.
Did the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the (K343) Fused
ASD Relay Output circuit. Inspect the related fuse and
repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
NOTE: Stop the actuation before continuing.
4.(K99) O2 1/1 HEATER CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance of the (K99) O2 Heater Control circuit (PWM)
from the O2 Sensor to the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (K99) O2 Heater Control (PWM) cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
Page 920 of 5267
5.(K99) HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (K99) O2 Heater Con-
trol (PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the Heater Control (PWM) cir-
cuit or the Heater Relay Control circuit depending on the O2
Sensor being tested.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 921 of 5267
P0032-O2 SENSOR 1/1 HEATER CIRCUIT HIGH
For a complete wiring diagramRefer to Section 8W.
Page 922 of 5267

When Monitored:
Battery voltage above 10.6 volts, ASD is powered up, and O2 heater is on.
Set Condition:
Desired state does not match Actual state.
Possible Causes
O2 HEATER TEST
O2 SENSOR HEATER ELEMENT
(K343) FUSED ASD RELAY OUTPUT CIRCUIT
HEATER CONTROL CIRCUIT OPEN
HEATER CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.O2 HEATER TEST
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool, actuate the O2 Heater test.
Monitor the O2 Heater Voltage for 5 minutes.
Did the voltage drop down close to zero during the Heater test?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
NOTE: Stop the actuation before continuing.
2.O2 HEATER ELEMENT
Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Measure the resistance of the O2 Heater element at the O2 Sensor
connector (component side).
On a four O2 Sensor system the resistance value for 1/1 and 2/1 O2
Heater elements is between 3.3 and 4.1 ohms and the 1/2 and 2/2 O2
Heater elements is between 4.0 and 5.0 ohms at 70° F(21.1°C).
NOTE: The resistance value will increase with warmer tempera-
tures.
Is the resistance within the listed specifications?
Ye s>>
Go To 3
No>>
Replace the O2 Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
Page 923 of 5267
3.(K342) FUSED ASD RELAY OUTPUT CIRCUIT OPEN
Ignition on, engine not running.
With the scan tool, actuate the O2 Heater Test.
Using a 12-volt test light connected to ground, probe the (K342) Fused
ASD Relay Output circuit at the O2 Sensor harness connector.
Did the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the (K342) Fused
ASD Relay Output circuit. Inspect the related fuse and
repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
NOTE: Stop the actuation before continuing.
4.HEATER CONTROL CIRCUIT OPEN
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance of the O2 Heater Control circuit (PWM) from the
O2 Sensor to the PCM harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the O2 Heater Control (PWM) circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
Page 924 of 5267
5.HEATER CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the O2 Heater Control
(PWM) circuit.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the Heater Control (PWM) cir-
cuit or the Heater Relay Control circuit depending on the O2
Sensor being tested.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 6
6.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 925 of 5267
P0051-O2 SENSOR 2/1 HEATER CIRCUIT LOW
For a complete wiring diagramRefer to Section 8W.
Page 926 of 5267

When Monitored:
Battery voltage above 10.6 volts, ASD is powered up, and O2 heater is on.
Set Condition:
Desired state does not match Actual state.
Possible Causes
O2 HEATER TEST
O2 SENSOR HEATER ELEMENT
(K343) FUSED ASD RELAY OUTPUT CIRCUIT
(K199) HEATER CONTROL CIRCUIT OPEN
(K199) HEATER CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.O2 HEATER TEST
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool, actuate the O2 Heater test.
Monitor the O2 Heater Voltage for 5 minutes.
Did the voltage drop down close to zero during the Heater test?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
NOTE: Stop the actuation before continuing.
2.O2 HEATER ELEMENT
Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Measure the resistance of the O2 Heater element at the O2 Sensor
connector (component side).
On a four O2 Sensor system the resistance value for 1/1 and 2/1 O2
Heater elements is between 3.3 and 4.1 ohms and the 1/2 and 2/2 O2
Heater elements is between 4.0 and 5.0 ohms at 70° F(21.1°C).
NOTE: The resistance value will increase with warmer tempera-
tures.
Is the resistance within the listed specifications?
Ye s>>
Go To 3
No>>
Replace the O2 Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)