TEST ACTION APPLICABILITY
2 Start the engine.
Inspect the exhaust system for leak between the engine and the O2 sensors.
Are there any exhaust leaks?All
Ye s®Repair or replace the leaking exhaust parts as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 3
3NOTE: Ensure the voltmeter leads meet the terminals in the connector and
that there is good terminal to wire connection.
NOTE: Ensure the voltmeter leads are connected for positive polarity
Perform a voltage drop test by backprobing the O2 Sensor Signal circuit at the O2
Sensor harness connector and at the PCM harness connector.
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 volt?All
Ye s®Go To 4
No®Repair the high resistance on the O2 Sensor Signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
4NOTE: Ensure the voltmeter leads meet the terminals in the connector and
that there is good terminal to wire connection.
NOTE: Ensure the voltmeter leads are connected for positive polarity
Backprobe between the O2 Sensor ground circuit at the O2 Sensor harness connector
and PCM harness connector.
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 volt?All
Ye s®Go To 5
No®Repair the high resistance on the O2 Sensor ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
5 If there are no possible causes remaining, view repair. All
Repair
Replace the O2 Sensor
Perform POWERTRAIN VERIFICATION TEST VER - 5.
80
DRIVEABILITY - GAS
P0133-1/1 O2 SENSOR SLOW RESPONSE ÐContinued
TEST ACTION APPLICABILITY
6NOTE: Check for contaminates that may have damaged the O2 Sensor:
contaminated fuel, unapproved silicone, oil and coolant.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Test Complete.
81
DRIVEABILITY - GAS
P0133-1/1 O2 SENSOR SLOW RESPONSE ÐContinued
Symptom List:
P0134-1/1 O2 SENSOR STAYS AT CENTER
P0140-1/2 O2 SENSOR STAYS AT CENTER
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0134-1/1 O2 SENSOR STAYS AT
CENTER.
When Monitored and Set Condition:
P0134-1/1 O2 SENSOR STAYS AT CENTER
When Monitored: Engine running for greater than 121 second. Coolant Temperature
greater than 66ÉC (150.8ÉF). Engine in closed loop fuel control mode.
Set Condition: O2 signal voltage is between .35 volt and .58 volt for a total of 30 seconds
and than O2 signal volt is 1.5 volts for 60 seconds. One trip fault.
P0140-1/2 O2 SENSOR STAYS AT CENTER
When Monitored: Engine running for greater than 121 second. Coolant Temperature
greater than 66ÉC (150.8ÉF). Engine in closed loop fuel control mode. Vehicle Speed greater
than 40 MPH.
Set Condition: O2 signal voltage is between .35 volt and .58 volt for a total of 30 seconds
and than O2 signal volt is 1.5 volts for 60 seconds. Two trip fault.
POSSIBLE CAUSES
INTERMITTENT CONDITION
O2 SENSOR OPERATION
O2 SENSOR GROUND CIRCUIT OPEN
O2 SENSOR SIGNAL OPEN
O2 SENSOR GROUND CIRCUIT VOLTAGE DROP
O2 SENSOR SIGNAL CIRCUIT VOLTAGE DROP
PCM
TEST ACTION APPLICABILITY
1NOTE: Check for contaminates that may have damaged the O2 Sensor:
contaminated fuel, unapproved silicone, oil and coolant.
Turn the ignition on.
With the DRBIIIt, read DTC's.
Is the Good Trip displayed and equal to zero?All
Ye s®Go To 2
No®Go To 8
82
DRIVEABILITY - GAS
TEST ACTION APPLICABILITY
2 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Turn the ignition on.
Connect a test light to battery voltage, probe the O2 Sensor Signal circuit in the O2
Sensor harness connector.
With the DRBIIIt, read the O2 Sensor voltage.
Is the voltage above 1.0 volts?All
Ye s®Replace the O2 Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 3
3 Turn the ignition off.
Disconnect the O2 Sensor harness connector
Disconnect the PCM harness connector.
Measure the resistance of the O2 Sensor ground circuit from the O2 Sensor harness
connector and the PCM harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the O2 Sensor ground circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
4 Turn the ignition off.
Disconnect the O2 Sensor harness connector
Disconnect the PCM harness connector.
Measure the resistance of the O2 Sensor Signal circuit from the O2 Sensor harness
connector and the PCM harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the O2 Sensor Signal for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
5NOTE: Ensure the voltmeter leads meet the terminals in the connector and
that there is good terminal to wire connection.
NOTE: Ensure the voltmeter leads are connected for positive polarity
Perform a voltage drop test by backprobe between the O2 Sensor ground circuit at the
O2 Sensor harness connector and PCM harness connector.
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 volt?All
Ye s®Go To 6
No®Repair the high resistance on the O2 Sensor ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
83
DRIVEABILITY - GAS
P0134-1/1 O2 SENSOR STAYS AT CENTER ÐContinued
TEST ACTION APPLICABILITY
6NOTE: Ensure the voltmeter leads meet the terminals in the connector and
that there is good terminal to wire connection.
NOTE: Ensure the voltmeter leads are connected for positive polarity
Perform a voltage drop test backprobe between the O2 Sensor Signal circuit at the O2
Sensor harness connector and PCM harness connector.
Start the engine.
Allow the engine to idle.
Is the voltage below 0.10 volt?All
Ye s®Go To 7
No®Repair the high resistance on the O2 Sensor Signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
7 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
8NOTE: Check for contaminates that may have damaged the O2 Sensor:
contaminated fuel, unapproved silicone, oil and coolant.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Test Complete.
84
DRIVEABILITY - GAS
P0134-1/1 O2 SENSOR STAYS AT CENTER ÐContinued
Symptom:
P0135-1/1 O2 SENSOR HEATER FAILURE
When Monitored and Set Condition:
P0135-1/1 O2 SENSOR HEATER FAILURE
When Monitored: During vehicle shutdown after vehicle had been driven greater than 10
miles with throttle open for a minimum of 3 minutes. Battery voltage greater than 11.0
volts.
Set Condition: O2 sensor voltage continues to rise (instead of fall) after the diagnostics
has turned the ASD relay back on. Two trip fault.
POSSIBLE CAUSES
O2 HEATER ELEMENT
O2 SENSOR HEATER CONTROL CIRCUIT OPEN
O2 SENSOR HEATER CONTROL CIRCUIT SHORTED TO GROUND
ASD RELAY OUTPUT CIRCUIT OPEN
INTERMITTENT CONDITION
PCM
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, read DTC's.
Is the Good Trip display and equal to zero?All
Ye s®Go To 3
No®Go To 2
2 Turn the ignition off.
NOTE: Wait a minimum of 8 minutes to allow the O2 Sensor to cool down
before continuing the test. Allow the O2 Sensor voltage to stabilize between
0.4 to 0.6 volts.
Turn the ignition on.
With the DRBIIIt, actuate the O2 Heater Test.
With the DRBIIIt, monitor O2 Sensor voltage for at least 2 minutes.
Does the voltage stay between 0.4 and 0.6All
Ye s®Go To 3
No®Go To 8
85
DRIVEABILITY - GAS
TEST ACTION APPLICABILITY
3NOTE: Allow the O2 sensor to cool down to room temperature.
Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Measure the resistance across the O2 Sensor Heater element component side.
Is the resistance between 2.0 and 7.0 ohms?All
Ye s®Go To 4
No®Replace the O2 Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
4 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance of the O2 Sensor Heater Control circuit between the O2
Sensor harness connector and the PCM harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the O2 Sensor Heater Control circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
5 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance of the O2 Sensor Heater Control circuit in the O2 Sensor
harness connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the O2 Sensor Heater Control circuit for a short to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 6
6 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
With the DRBIIIt, actuate the O2 Heater Test.
Measure the voltage of the ASD Relay Output circuit in the O2 Sensor harness
connector.
Is the voltage above 11.0 volts?All
Ye s®Go To 7
No®Repair the ASD Relay Output circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
7 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
86
DRIVEABILITY - GAS
P0135-1/1 O2 SENSOR HEATER FAILURE ÐContinued
TEST ACTION APPLICABILITY
8WARNING: KEEP CLEAR OF THE ENGINE'S MOVING PARTS.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Test Complete.
87
DRIVEABILITY - GAS
P0135-1/1 O2 SENSOR HEATER FAILURE ÐContinued