Page 3865 of 4284
Symptom:
P0125-CLOSED LOOP TEMP NOT REACHED
When Monitored and Set Condition:
P0125-CLOSED LOOP TEMP NOT REACHED
When Monitored: With battery voltage greater than 10.4 volts, after engine is started.
Set Condition: The engine temperature does not go above 60ÉF (15ÉC). F Time depen-
dants on start-up coolant temperature and ambient temperature. (i.e. 2 minutes for a start
temp of 10ÉC (50ÉF) or up to 10 mintues for a vehicle with a start-up temp of -28ÉC (20ÉF).
Two trips are required to set this DTC.
POSSIBLE CAUSES
LOW COOLANT LEVEL
THERMOSTAT OPERATION
ENGINE COOLANT TEMPERATURE SENSOR
TEST ACTION APPLICABILITY
1NOTE: If a ECT DTC set along with this code, diagnose the ECT DTC first.
NOTE: Inspect the ECT terminals and related PCM terminals. Ensure the
terminals are free from corrosion and damage.
NOTE: The best way to diagnose this DTC is to allow the vehicle to sit
overnight outside in order to have a totally cold soaked engine.
Note: Extremely cold outside ambient temperatures may have caused this
DTC to set.
WARNING: Never open the cooling system when the engine is hot. The
system is under pressure. Extreme burns or scalding may result. Allow the
engine to cool before opening the cooling system.
Check the coolant system to make sure that the coolant is in good condition and at
the proper level.
Is the coolant level and condition OK?All
Ye s®Go To 2
No®Inspect the vehicle for a coolant leak and add the necessary
amount of coolant.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
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DRIVEABILITY - GAS
Page 3866 of 4284
TEST ACTION APPLICABILITY
2Note: This test works best if performed on a cold engine (cold soak)
Turn the ignition on.
With the DRBIIIt, read the Eng Coolant Tmp Deg value. If the engine was allowed
to sit overnight (cold soak), the temperature value should be a sensible value that is
somewhere close to the ambient temperature.
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 65ÉC (150ÉF) is reached.
Start the Engine.
Using the appropriate service information, determine the proper opening tempera-
ture of the thermostat.
Did the thermostat open at the proper temperature?All
Ye s®Go To 3
No®Replace the thermostat.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
3 Turn the ignition on.
With the DRBIIIt, read the Eng Coolant Tmp Deg value. If the engine was allowed
to sit overnight (cold soak), the temperature value should be a sensible value that is
somewhere close to the ambient temperature.
Note: If engine coolant temperature is above 82ÉC (180ÉF), allow the engine
to cool until 65ÉC (150ÉF) is reached.
Start the Engine.
During engine warm-up monitor the Eng Coolant Tmp Deg value. The temp deg
value change should be a smooth transition from start up to normal operating temp
82ÉC (180ÉF) . Also monitor the actual coolant temperature with a thermometer.
NOTE: As the engine warms up to operating temperature, the actual coolant
temperature (thermometer reading) and the Eng Coolant Tmp Deg in the
DRB values should stay relatively close to each other.
Does the actual coolant temperature and the reading on the DRBIIItremain
relatively the same with aAll
Ye s®Test Complete.
No®Replace the Engine Coolant Temperature Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
72
DRIVEABILITY - GAS
P0125-CLOSED LOOP TEMP NOT REACHED ÐContinued
Page 3867 of 4284
Symptom List:
P0131-1/1 O2 SENSOR SHORTED TO GROUND
P0137-1/2 O2 SENSOR SHORTED TO GROUND
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0131-1/1 O2 SENSOR SHORTED
TO GROUND.
When Monitored and Set Condition:
P0131-1/1 O2 SENSOR SHORTED TO GROUND
When Monitored: At engine shutdown O2 Heater Diagnostics test. Then at subsequent
cold start. Cold start is defined as engine coolant below 37ÉC (100ÉF), ambient/battery
sensor reading within 6.6ÉC (44ÉF), and engine coolant temperature above 88ÉC (170ÉF) on
the previous key off.
Set Condition: The oxygen sensor signal voltage is below 0.078 volts for 5 seconds after
starting engine.
P0137-1/2 O2 SENSOR SHORTED TO GROUND
When Monitored: Engine running for 119 seconds. Coolant temperature above 80ÉC
(176ÉF). Vehicle speed greater than 40 mph. Two trip fault.
Set Condition: The oxygen sensor signal voltage is below 0.078 volts for 61 seconds after
starting engine.
POSSIBLE CAUSES
INTERMITTENT CONDITION
O2 SENSOR OPERATION
O2 SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
O2 SENSOR SIGNAL CIRCUIT SHORTED TO SENSOR GROUND CIRCUIT
O2 SENSOR SIGNAL SHORTED TO HEATER GROUND/CONTROL CIRCUIT
PCM
TEST ACTION APPLICABILITY
1 Start the engine.
Allow the engine to idle.
With the DRBIIIt, read the O2 Sensor voltage.
Is the voltage below 0.08?All
Ye s®Go To 2
No®Go To 7
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Page 3868 of 4284
TEST ACTION APPLICABILITY
2WARNING: 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.
Start the engine.
Disconnect the O2 Sensor harness connector.
With the DRBIIIt, monitor the O2 Sensor voltage.
Is the O2 Sensor voltage above 0.08?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 Signal circuit in the O2 Sensor harness
connector to ground.
Is the resistance below 100 ohms?All
Ye s®Repair the O2 Sensor Signal circuit for a short to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 4
4 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance between the O2 Sensor Signal circuit and the Sensor ground
circuit in the O2 Sensor harness connector.
Is the resistance below 100 ohms?All
Ye s®Repair the O2 Sensor Signal circuit for a short to the Sensor
ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 5
5 Turn the ignition off.
Disconnect the O2 Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance between the O2 Sensor Signal circuit and the Heater
ground/control circuit in the O2 Sensor harness connector.
Is the resistance below 100 ohms?All
Ye s®Repair the O2 Sensor Signal circuit for a short to the Heater
ground/control circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 6
6 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.
74
DRIVEABILITY - GAS
P0131-1/1 O2 SENSOR SHORTED TO GROUND ÐContinued
Page 3869 of 4284
TEST ACTION APPLICABILITY
7WARNING: 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.
75
DRIVEABILITY - GAS
P0131-1/1 O2 SENSOR SHORTED TO GROUND ÐContinued
Page 3870 of 4284
Symptom List:
P0132-1/1 O2 SENSOR SHORTED TO VOLTAGE
P0138-1/2 O2 SENSOR SHORTED TO VOLTAGE
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P0132-1/1 O2 SENSOR SHORTED
TO VOLTAGE.
When Monitored and Set Condition:
P0132-1/1 O2 SENSOR SHORTED TO VOLTAGE
When Monitored: Engine running for 119 seconds. Battery voltage greater than 10 volts.
Coolant temperature above 80ÉC (176ÉF).
Set Condition: The Oxygen Sensor voltage is above 1.29 volts for 30 seconds. Two trip
fault.
P0138-1/2 O2 SENSOR SHORTED TO VOLTAGE
When Monitored: The engine running for 119 seconds. Battery voltage greater than 10
volts. Coolant temperature above 80ÉC (176ÉF).
Set Condition: The Oxygen Sensor voltage is above 1.29 volts for 30 seconds. Two trip
fault.
POSSIBLE CAUSES
INTERMITTENT CONDITION
O2 SENSOR OPERATION
O2 SENSOR SIGNAL SHORTED TO VOLTAGE
O2 SENSOR SIGNAL OPEN
O2 SENSOR GROUND CIRCUIT OPEN
PCM
TEST ACTION APPLICABILITY
1 Start the engine.
Allow the engine to idle.
With the DRBIIIt, read the O2 Sensor voltage.
Is the voltage above 1.2 volts?All
Ye s®Go To 2
No®Go To 7
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DRIVEABILITY - GAS
Page 3871 of 4284
TEST ACTION APPLICABILITY
2WARNING: 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.
Start the engine.
Disconnect the O2 Sensor harness connector.
With the DRBIIIt, monitor the O2 Sensor voltage.
Is the O2 Sensor voltage below 1.2 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
Start the engine and allow the engine to idle.
Measure the voltage of the O2 Sensor Signal circuit in the O2 Sensor harness
connector.
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.
Is the voltage above 1.2 volts?All
Ye s®Repair the O2 Sensor Signal circuit for a shorted to voltage.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 4
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.
5 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 6
No®Repair the O2 Sensor ground cirucit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
6 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.
77
DRIVEABILITY - GAS
P0132-1/1 O2 SENSOR SHORTED TO VOLTAGE ÐContinued
Page 3872 of 4284
TEST ACTION APPLICABILITY
7WARNING: 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.
78
DRIVEABILITY - GAS
P0132-1/1 O2 SENSOR SHORTED TO VOLTAGE ÐContinued