When Monitored:
At a cold start, engine coolant below 98°F, Ambient/Battery Sensor readingwithin27°F,andEngineCoolant
Temperature above 170°F on the previous key off.
Set Condition:
The Oxygen Sensor signal voltage is below 0.156 of a volt for 28 seconds after starting engine.
Possible Causes
(K243) O2 SENSOR 2/2 SIGNAL CIRCUIT SHORTED TO GROUND
(K243) O2 SENSOR 2/2 SIGNAL CIRCUIT SHORTED TO (K900) SENSOR GROUND CIRCUIT
(K243) O2 SENSOR 2/2 SIGNAL SHORTED TO THE (Z1) HEATER GROUND CIRCUIT
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR BELOW 0.16 OF A VOLT
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Start the engine.
Allow the engine to idle for 4 to 5 minutes.
With the scan tool, read the O2 Sensor voltage.
Is the voltage below 0.16 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.O2 SENSOR OPERATION
WARNING: When the engine is operating, do not stand in a direct line with thefan. Do not put your hands
near the pulleys, belts, or fan. Do not wear loose clothing.
Disconnect the O2 Sensor harness connector.
Start the engine.
With the scan tool, monitor the O2 Sensor voltage.
IstheO2Sensorvoltageabove0.16ofavolt?
Ye s>>
Replace the O2 Sensor
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
Continuously after the ignition is turned on and the battery voltage is above 10.4 volts.
Set Condition:
Not powering down, not in limp-in and time since last solenoid activation is greater than 72 micro seconds. The
PCM will set a trouble code if the actual state of the solenoid does not matchthe intended state on two con-
secutive key cycles.
Possible Causes
(F202) FUSED IGNITION SWITCH OUTPUT CIRCUIT OPEN
EVAP PURGE SOLENOID
(K70) EVAP PURGE SOLENOID CONTROL CIRCUIT OPEN
(K70) EVAP PURGE SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
Ignition on, engine not running.
With a scan tool, read DTCs and record the related Freeze Frame data if any DTC(s) are present.
Whether or not any DTC(s) are present you will want to check the following items which may assist in repairing the
customer’s complaint successfully.
Check the vehicles repair history.
If the vehicle has a repair history that pertains to the customer’s currentcomplaint, review the repair.
Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
Check for any service bulletin(s) related to the customer’s complaint or DTC(s).
If a service bulletin applies, follow the instructions per the service bulletin.
Choose the following scenario that best applies.
The service bulletin repaired the customer’s complaint.
Testing complete.
A DTC is present, no service bulletins apply, or the service bulletin didn’t repair the customer’s complaint.
Go To 2
2.ACTIVE DTC
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 3
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P0513-INVALID SKREEM KEY
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on.
Set Condition:
The Gateway detects that the Secret Key message is invalid or missing. One Trip Fault.
Possible Causes
WCM/SKREEM
POWERTRAIN CONTROL MODULE
GATEWAY MODULE
COMMUNICATION PROBLEM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With the scan tool, read the Gateway Module DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.COMMUNICATION (CAN BUS or J1850)
NOTE: For vehicle communication problems, use the scan tool to refer to theNetwork Review Screen. The
screen depicts a high level view of the vehicle network. Fault and problem areas appear in red. Selecting
any of the network components allows access to the source of the problem.
Does the scan tool display a Vehicle Network problem or NO RESPONSE condition?
Ye s>>
Refer to the appropriate BUS Communication test in the Section 8 ELECTRONIC CONTROL MODULE
- ELECTRICAL DIAGNOSTICS.
No>>
Go To 3
3.SKREEM/SKIM TROUBLE CODES SET
With the scan tool, check for SKREEM/SKIM DTCs.
Are any DTCs present in the SKREEM/SKIM?
Ye s>>
Refer to Section 8 - Electrical VEHICLE THEFT SECURITY - ELECTRICAL DIAGNOSTICS and perform
the appropriate Diagnostic Procedure.
No>>
Go To 4
When Monitored:
With the ignition key on and the engine running.
Set Condition:
When the PCM tries to regulate the generator field with no result during monitoring.
Possible Causes
(K125) GEN FIELD SOURCE CIRCUIT OPEN
(K20) GEN FIELD CONTROL CIRCUIT OPEN
(K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND
GENERATOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GENERATOR FIELD PERFORMANCE
Ignition on, engine not running.
Record all DTCs and the related Freeze Frame data.
Turn the ignition off.
Disconnect the Generator harness connector.
Ignition on, engine not running.
Using a 12-volt test light connected to 12-volts, probe the (K20) Gen
Field Control circuit at the Generator harness connector.
With the scan tool, actuate the Generator Field Driver.
Does the test light blink?
Ye s>>
Refer to the INTERMITTENT CONDITION Diagnostic Pro-
cedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.(K125) GEN FIELD SOURCE CIRCUIT OPEN
Turn the ignition off.
Disconnect the C2 and C3 PCM harness connectors.
Carefully inspect all connectors for corrosion or spread terminals before
continuing.
Measure the resistance of the (K125) Generator Field Source circuit
from the Generator harness connector to the C3 PCM harness connec-
tor.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 3
No>>
Repair the open in the (K125) Gen Field Source circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
P1281-ENGINE IS COLD TOO LONG
For a complete wiring diagramRefer to Section 8W.
When Monitored:
The ignition key on, engine running.
Set Condition:
The engine does not warm to 176 Deg. F while driving for 20 minutes after start.
Possible Causes
ENGINE COLD TOO LONG
ECT SENSOR OPERATION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.CHECK COOLING SYSTEM PERFORMANCE
NOTE: The best way to diagnose this DTC is to allow the vehicle to remain outside overnight in order to
have a completely cold soaked engine.
NOTE: Extremely cold outside ambient temperatures may cause this DTC to set.
Verify that the coolant level is not low and correct as necessary.
Start the engine.
With the scan tool, set the engine RPM to 1500 and allow the engine to warm up for 10-15 minutes.
With the scan tool, monitor the ENG COOLANT TMP DEG value during the warm up cycle. Make sure the transition
of temperature change is smooth.
Did the engine temperature reach a minimum of 80° C (176° F)?
Ye s>>
Go To 2
No>>
Refer to the Service Information for cooling system performance diagnosis. The most probable cause is
a Thermostat problem. Also, refer to any related TSBs.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ECT SENSOR OPERATION
WARNING: WARNING: MAKE SURE THE ENGINE COOLING SYSTEM IS COOL BEFORE REMOVING THE
PRESSURE CAP OR ANY HOSE. SEVERE PERSONAL INJURY MAY RESULT FROM ESCAPING HOT COOL-
ANT. THE COOLING SYSTEM IS PRESSURIZED WHEN HOT.
With the scan tool, read and record the ECT Sensor Temperature value.
Using the DRB Temperature Probe #CH7050, measure the engine coolant temperature.
NOTE: The t-stat housing area should be around 192-195 at start to open.
Is the ECT Sensor value with -15°C (5°F) of the temperature probe reading?
Ye s>>
Te s t C o m p l e t e .
No>>
Replace the ECT Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
During power-down and battery voltage greater than 10.4 volts.
Set Condition:
The MAP sensor signal voltage goes below 2.35 volts with the key off for 5 seconds.
Possible Causes
MAP SENSOR VOLTS BELOW 2.3 VOLTS
MAP SENSOR
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
SHORTED SENSOR
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.MAP SENSOR VOLTS BELOW 2.3 VOLTS
NOTE: If the P0107 - MAP Sensor Voltage Too Low is also set, diagnose it firstbefore continuing with P1296
- No 5-volts To MAP Sensor.
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool in Sensors, read the MAP Sensor voltage.
Is the voltage below 2.35 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(F855) 5-VOLT SUPPLY CIRCUIT
Turn the ignition off.
Disconnect the MAP Sensor harness connector.
Ignition on, engine not running.
Measure the voltage on the (F855) 5-volt Supply circuit at the MAP
Sensor harness connector.
Is the voltage above 4.5 volts?
Ye s>>
Go To 3
No>>
Go To 4
When Monitored:
With ignition key on and battery voltage above 10.4 volts.
Set Condition:
An open or shorted condition is detected in the ASD Relay control circuit.
Possible Causes
GOOD TRIP EQUAL TO ZERO
ASD RELAY
(A14) FUSED B+ OUTPUT CIRCUITS
(K51) ASD RELAY CONTROL CIRCUIT OPEN
(K51) ASD RELAY CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ASD RELAY
Turn the ignition off.
Remove the ASD Relay from the PDC.
Measure the resistance between the coil terminals of the ASD Relay.
Is the resistance between 50 and 80 ohms?
Ye s>>
Go To 3
No>>
Replace the ASD Relay.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
3.(A14) FUSED B+ OUTPUT CIRCUIT
Using a 12-volt test light connected to ground, probe the (A14) Fused B+ Output circuits in the ASD Relay con-
nector.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the (A14) Fused B+ Output circuits. Inspect the related fuse and
repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
When Monitored:
With ignition key on, battery voltage above 10.4 volts, and engine RPM greater than 400.
Set Condition:
No voltage sensed at the PCM when the ASD Relay is energized.
Possible Causes
GOOD TRIP EQUAL TO ZERO
ASD RELAY
(A14) FUSED B+ CIRCUITS
(K342) ASD RELAY OUTPUT CIRCUIT OPEN
(K342) ASD OUTPUT CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.ENGINE STARTING STATUS
Attempt to start the engine.
Did the engine start?
Ye s>>
Go To 3
No>>
Go To 4
3.(K342) ASD OUTPUT CIRCUIT OPEN
Turn the ignition off.
Remove the ASD Relay from the PDC.
Disconnect the PCM harness connectors.
Measure the resistance of the (K342) ASD Relay Output circuit from the ASD Relay cavity in the PDC to the PCM
harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 7
No>>
Repair the open in the (K342)ASD Relay Output circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)