Symptom:
P-0117 ECT SENSOR VOLTAGE TOO LOW
When Monitored and Set Condition:
P-0117 ECT SENSOR VOLTAGE TOO LOW
When Monitored: With the ignition on.
Set Condition: The engine coolant temperature sensor circuit voltage at PCM cavity 26
goes below .5 volt for more than 3 seconds.
POSSIBLE CAUSES
ECT SENSOR VOLTAGE ABOVE 4.0 VOLTS
ECT SENSOR SIGNAL CIRCUIT SHORT TO GROUND
ECT SENSOR SIGNAL CIRCUIT SHORTED TO GROUND CKT
ECT WIRING HARNESS INTERMITTENT DEFECT
ECT WIRING HARNESS OBSERVABLE DEFECT
PCM DEFECTIVE (ECT SENSOR V LOW)
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the Engine Coolant Temperature (ECT) Sensor voltage.
Is the Engine Coolant Temperature Sensor voltage below 0.5 volt?All
Ye s®Go To 2
No®Go To 6
2 Ignition Off
Disconnect the Engine Coolant Temperature (ECT) Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Ignition on, engine not running.
With the DRB, read the Engine Coolant Temperature Sensor voltage.
Is the ECT Sensor voltage above 4.0 volts?All
Ye s®Replace the Engine Coolant Temperature Sensor.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
38
DRIVEABILITY
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Ignition Off
Disconnect the Engine Coolant Temperature Sensor (ECT) Connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the Powertrain Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
With an ohmmeter, measure the resistance between the ECT Sensor Signal Circuit
and the ECT Sensor Ground Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the ECT Sensor Signal Circuit shorted to the ECT Sensor
Ground Circuit.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
4 Ignition Off
Disconnect the Engine Coolant Temperature (ECT) Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the Powertrain Control Module Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the ECT Sensor Signal Circuit to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the ECT Sensor Signal Circuit for a short to ground.
Perform Powertrain Verification Test VER-5A.
No®Go To 5
5 Ignition Off
If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the Powertrain Control Module.
Perform Powertrain Verification Test VER-5A.
6 Ignition On, Engine Not Running
Using the schematic, wiggle the ECT Sensor Connector and Harness.
Monitor the DRB display.
Was there any ECT Sensor voltage change?All
Ye s®Repair the Harness or Connector that caused the voltage change.
Perform Powertrain Verification Test VER-5A.
No®Go To 7
7 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Test Complete.
39
DRIVEABILITY
P-0117 ECT SENSOR VOLTAGE TOO LOW ÐContinued
ProCarManuals.com
Symptom:
P-0118 ECT SENSOR VOLTAGE TOO HIGH
When Monitored and Set Condition:
P-0118 ECT SENSOR VOLTAGE TOO HIGH
When Monitored: With the ignition on.
Set Condition: The engine coolant temperature sensor circuit voltage at PCM cavity 26
goes above 4.9 volts for more than 3 seconds.
POSSIBLE CAUSES
ECT SENSOR DEFECTIVE
ECT SENSOR GROUND CIRCUIT OPEN
ECT SENSOR SIGNAL CIRCUIT OPEN
ECT SENSOR WIRING HARNESS INTERMITTENT DEFECT
ECT SENSOR WIRING HARNESS OBSERVABLE DEFECT
PCM DEFECTIVE
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
With the DRB, read the ECT Sensor voltage.
Is the ECT Sensor voltage above 4.9 volts?All
Ye s®Go To 2
No®Go To 6
2 Ignition On, Engine Not Running
Disconnect the ECT Sensor.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the ECT Sensor Signal Circuit and the Sensor
Ground Circuit.
With the DRB, read the ECT Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s®Replace the ECT Sensor.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
40
DRIVEABILITY
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Ignition Off
Disconnect the ECT Sensor Electrical Connector.
Note: Check connectors - Clean/repair as necessary.
Connect a jumper wire between the ECT Sensor Signal Circuit and an engine ground.
Turn the ignition on, with the engine not running.
With the DRB, read the Engine Coolant Temperature Sensor voltage.
Is the voltage below 1.0 volt?All
Ye s®Repair the open ECT Sensor Ground Circuit.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
4 Ignition Off
Disconnect the ECT Sensor Connector.
Note: Check connectors - Clean/repair as necessary.
Disconnect the PCM Connector.
Note: Check connectors - Clean/repair as necessary.
Using an Ohmmeter, measure the ECT Sensor Signal Circuit from the PCM to the
ECT.
Is the resistance below 5.0 ohms?All
Ye s®Go To 5
No®Repair the open ECT Sensor Signal Circuit.
Perform Powertrain Verification Test VER-5A.
5 Ignition Off
If there are no potential causes remaining, the PCM is assumed to be defective.
View repair options.All
Repair
Replace the PCM.
Perform Powertrain Verification Test VER-5A.
6 Ignition On, Engine Not Running
Use the schematic as a guide and wiggle the ECT Sensor Connector & Harness.
Monitor the DRB display.
Was there any ECT Sensor voltage change?All
Ye s®Repair the Harness or Connector that caused the voltage change.
Perform Powertrain Verification Test VER-5A.
No®Go To 7
7 Ignition Off
Using the schematic as a guide, inspect the Wiring and Connectors.
Were any problems found?All
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Test Complete.
41
DRIVEABILITY
P-0118 ECT SENSOR VOLTAGE TOO HIGH ÐContinued
ProCarManuals.com
Symptom:
P-0125 CLOSED LOOP TEMP NOT REACHED
When Monitored and Set Condition:
P-0125 CLOSED LOOP TEMP NOT REACHED
When Monitored: After engine is started, for ten minutes.
Set Condition: The engine temperature does not go above 10 degrees C (50 degrees F) by
13 minutes after the engine is started for 2 consecutive trips.
POSSIBLE CAUSES
PCM CONNECTOR AND TERM DAM, PSHD OUT, OR MISWIRED
ECT SENSOR CONN AND TERM DAM, PSHD OUT, MISWIRED
ECT SENSOR RESISTANCE >=11.00 K OHMS
PCM DEFECTIVE
THERMOSTAT DEFECTIVE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, read the FREEZE FRAME DATA.
Using the FREEZE FRAME DATA, attempt to duplicate the condition that has set
this fault.
Note that the DTC is a 2 trip failure.
Does P0121 reset?All
Ye s®Go To 3
No®Go To 2
2 The conditions required to set the DTC are no longer present.
Ensure the engine cooling system is operating properly, coolant level is at specifica-
tion, and no external or internal coolant leaks. Refer to the appropriate service
category for cooling system information.
Is the Cooling System operating correctly?All
Ye s®Test complete
No®Repair as necessary.
Perform Powertrain verification Test VER-5A
3 Ignition off.
Disconnect the ECT Sensor Connector.
Note: Check Connectors - clean/repair as necessary.
Is any Terminal damaged, pushed out, or miswired?All
Ye s®Clean or repair connector as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
51
DRIVEABILITY
ProCarManuals.com
Symptom:
P-0132 1/1 O2 SENSOR SHORTED TO VOLTAGE
When Monitored and Set Condition:
P-0132 1/1 O2 SENSOR SHORTED TO VOLTAGE
When Monitored: With the engine running for more than 2 minutes and coolant
temperature above 76 degrees C (170 degrees F).
Set Condition: The Upstream Oxygen Sensor Signal voltage is above 1.2 volts.
POSSIBLE CAUSES
1/1 O2 SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
1/1 O2 SEN HARNESS INTERMITTENT SHORT TO VOLTAGE
1/1 O2 SENSOR CONNECTOR OBSERVABLE DEFECT (A)
1/1 O2 SENSOR CONNECTOR OBSERVABLE DEFECT (B)
1/1 O2 SENSOR HARNESS OBSERVABLE DEFECT
1/1 O2 SENSOR DEFECTIVE
TEST ACTION APPLICABILITY
1 Start the engine.
With the DRB, read the Upstream O2 Sensor voltage.
Is the Upstream O2 Sensor voltage above 1.2 volts?All
Ye s®Go To 2
No®Go To 5
2 Ignition Off
Disconnect the Upstream O2 Sensor.
Note: Check connectors - Clean/repair as necessary.
Start the engine.
With the DRB, read the Upstream O2 Sensor Voltage.
Is the Upstream O2 Sensor voltage above 1.2 volts?All
Ye s®Repair the Upstream O2 Sensor Signal Circuit for a short to
voltage. If ok, replace the PCM.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
3 Ignition Off
Disconnect the Upstream O2 Sensor.
Note: Check connectors - Clean/repair as necessary.
Is any Terminal damaged, pushed out or miswired?All
Ye s®Repair or replace as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
55
DRIVEABILITY
ProCarManuals.com
TEST ACTION APPLICABILITY
3 Turn Ignition On (Engine Off).
During the following voltage drop measurement, wiggle wires between O2S Connec-
tor and PCM Connector.
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
While wiggling wires, is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 4
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
4 At this time the 1/1 O2S SLOW RESPONSE does not exist or is an intermittent
problem.
With the DRB, read the FREEZE FRAME DATA.
With this screen, attempt to duplicate the condition that has set this fault.
While using FREEZE FRAME pay particular attention to the fault setting condi-
tions, such as speed, temp, load, and map vacuum.
Does the 1/1 O2S SLOW RESPONSE reoccur?All
Ye s®Go To 5
No®The 1/1 O2S SLOW RESPONSE no longer exists.
Perform VERIFICATION TEST VER-5A3.
5 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
NOTE: Check the exhaust for excessive smoke caused by oil or coolant
consumption.
Is there an oil or coolant consumption condition present?All
Ye s®Repair engine mechanical as necessary and replace O2 Sensor.
Perform VERIFICATION TEST VER-5A3.
No®Go To 6
6 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Start the Engine.
Check the Exhaust System for leaks between the Engine and the catalyst.
Are there any leaks?All
Ye s®Repair or replace leaking Exhaust System as necessary.
Perform VERIFICATION TEST VER-5A3.
No®Go To 7
7 The following are possible causes for O2 Sensor Slow Response: exhaust leak, fuel
contamination, O2 sensor failure, electrical wiring connectors, electrical mechanical,
and O2 heater failure.
Turn Ignition On (Engine Off).
Using a voltmeter, backprobe O2S (Signal) Circuit between O2S Connector (O2S
Signal) and PCM Connector (O2S Signal).
Is the voltage drop reading below 0.10 VDC?All
Ye s®Go To 8
No®Repair poor connection (high resistance) on O2S Signal Circuit.
Perform VERIFICATION TEST VER-5A3.
58
DRIVEABILITY
P-0133 1/1 O2S SLOW RESPONSE ÐContinued
ProCarManuals.com
Symptom:
P-0138 1/2 O2 SENSOR SHORTED TO VOLTAGE
When Monitored and Set Condition:
P-0138 1/2 O2 SENSOR SHORTED TO VOLTAGE
When Monitored: With the engine running for more than 2 minutes and coolant
temperature above 76 degrees C (170 degrees F).
Set Condition: The Downstream Oxygen Sensor Signal voltage is above 1.2 volts.
POSSIBLE CAUSES
1/2 O2 SENSOR SIGNAL CIRCUIT SHORT TO VOLTAGE
1/2 O2 SEN HARNESS INTERMITTENT SHORT TO VOLTAGE
1/2 O2 SENSOR CONNECTOR OBSERVABLE DEFECT (A)
1/2 O2 SENSOR CONNECTOR OBSERVABLE DEFECT (B)
1/2 O2 SENSOR HARNESS OBSERVABLE DEFECT
1/2 O2 SENSOR DEFECTIVE
TEST ACTION APPLICABILITY
1 Start the engine.
With the DRB, read the Downstream O2 Sensor voltage.
Is the Downstream O2 Sensor voltage above 1.2 volts?All
Ye s®Go To 2
No®Go To 5
2 Ignition Off
Disconnect the Downstream O2 Sensor.
Note: Check connectors - Clean/repair as necessary.
Start the engine.
With the DRB, read the Downstream O2 Sensor Voltage.
Is the Upstream O2 Sensor voltage above 1.2 volts?All
Ye s®Repair the Downstream O2 Sensor Signal Circuit for a short to
voltage. If ok, replace the PCM.
Perform Powertrain Verification Test VER-5A.
No®Go To 3
3 Ignition Off
Disconnect the Downstream O2 Sensor.
Note: Check connectors - Clean/repair as necessary.
Is any Terminal damaged, pushed out or miswired?All
Ye s®Repair or replace as necessary.
Perform Powertrain Verification Test VER-5A.
No®Go To 4
66
DRIVEABILITY
ProCarManuals.com