When Monitored:
With the ignition on and battery voltage above 10.4 volts.
Set Condition:
An open or shorted condition is detected in the Fuel Pump Relay Control circuit.
Possible Causes
FUEL PUMP RELAY OPERATION
FUEL PUMP RELAY
FUSED IGNITION SWITCH OUTPUT CIRCUIT
(K31) FUEL PUMP RELAY CONTROL CIRCUIT OPEN
(K31) FUEL PUMP RELAY CONTROL CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.FUEL PUMP RELAY OPERATION
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
With the scan tool, actuate the Fuel Pump Relay.
Is the Fuel Pump Relay clicking?
Ye s>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.FUEL PUMP RELAY
Turn the ignition off.
Remove the Fuel Pump Relay.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the coil terminals of the Fuel Pump Relay.
Is the resistance between 50 and 90 ohms?
Ye s>>
Go To 3
No>>
Replace the Fuel Pump Relay.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
3.FUSED IGNITION SWITCH CIRCUIT OPEN
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch Output circuit in the Fuel Pump
Relay connector.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open or short to ground in the Fused Ignition Switch Output circuit. Inspect the related fuse
and repair as necessary.
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)
P1398-MIS-FIRE ADAPTIVE NUMERATOR AT LIMIT
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Under closed throttle decel and Fuel Pulse Width equal to zero for 30 seconds.
Set Condition:
One of the CKP sensor target windows has more than 2.86% variance from the reference window.
Possible Causes
ADAPTIVE NUMERATOR RELEARN
CMP SENSOR CONNECTOR/WIRING
CKP SENSOR CONNECTOR/WIRING
DAMAGED TONE WHEEL/FLEX PLATE (CRANKSHAFT)
CRANKSHAFT POSITION SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.ADAPTIVE NUMERATOR RELEARN
NOTE: Check for any TSB’s that may apply to this symptom.
Read and record the Freeze Frame Data. Use this information to help you duplicate the conditions that set the DTC.
Pay particular attention to the DTC set conditions, such as, VSS, MAP, ECT,and Load.
Ignition on, engine not running.
With the scan tool in the miscellaneous menu, choose Clear PCM (battery disconnect) to reset the PCM.
With the scan tool, choose the Misfire Pretest screen.
Road test the vehicle and re-learn the adaptive numerator.
The adaptive numerator is learned when the Adaptive Numerator Done Learning line on the Misfire screen changes
to Yes.
Did the adaptive numerator re-learn?
Ye s>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.CMP CONNECTOR/HARNESS INSPECTION
Turn ignition off.
NOTE: Visually inspect the related wire harness connectors. Look for broken, bent, pushed out, or corroded
terminals.
NOTE: Visually inspect the related wire harness. Look for any chafed, pierced, pinched, or partially broken
wires.
NOTE: Make sure the Camshaft Position Sensor is tight.
NOTE: Refer to any technical service bulletins that may apply.
Were any problems found?
Ye s>>
Repair as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
Immediately after a cold start, with battery/ambient temperature between 40 deg. F and 90 Deg. F and coolant
temperature within 10 Deg. F of battery/ambient.
Set Condition:
LDP test must pass first. If the PCM suspects a pinched hose it will not set a fault until it runs the EVAP purge
flow monitor. If the purge monitor does not pass then the pinched hose faultwill be set.
Possible Causes
EVAP CANISTER OBSTRUCTED
OBSTRUCTION IN HOSE/TUBE BETWEEN EVAP CANISTER AND PURGE SOLENOID
LDP PRESSURE HOSE OBSTRUCTED
LEAK DETECTION PUMP
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.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 3
No>>
Go To 8
3.EVAP PURGE SOLENOID VACUUM LINE
Turn the ignition off.
Inspect the Purge Solenoid Vacuum line that runs from the Evap Purge Solenoid to the throttle body or intake man-
ifold.
Is the vacuum line plugged or kinked?
Ye s>>
Repair or replace the vacuum line from the solenoid to the throttle body / intake manifold.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
NOTE: Reconnect the vacuum line before continuing.
4.CHECKED FOR OTHER BLOCKED HOSES
To continue testing you will need Miller Tool #6872A (Evap System PressurePump) and #8382 (Gas Cap Tester [
]Adapter).
WARNING: The test equipment is designed to be used to pressurize the vehicles Evaporative System only.
Using the equipment in a manner for which it was not designed could be harmful.
WARNING: Keep lit cigarettes, sparks, flames, and other ignition sourcesaway from the test area to prevent
the ignition of explosive gases. Keep the test area well ventilated.
NOTE: The fuel tank should have between 20% and 80% of full to properly test the Evap System.
Attach the power source clip (red) of Miller Tool #6872A to Battery (+) and the ground clip (black) to Battery (-).
Perform the Evaporative System Pressure Pump self test that is specified on the tester cover.
Remove gas cap and install Miller Tool #8382 on the vehicle. Install gas capto Miller Tool #8382. Attach the pres-
sure supply hose from Miller Tool #6872A to the fitting on #8382.
Disconnect the vacuum supply hose at the Leak Detection Pump.
Connect and apply a continuous vacuum supply (i.e. 20”Hg) to the Leak Detection Pump. A vacuum pump such as
an A/C Recovery unit works well.
Ignition on, engine not running.
With the scan tool perform the “Leak Detect Pump Test”. Follow the scan toolinstructions and then press ENTER.
Select#3–HOLDPSI.
On Miller Tool #6872A, set the Pressure/Hold switch to Open and set the Ventswitch to Closed. Turn the pump
timer On and watch the gauge.
When the gauge pressure reaches 14”H2O, turn the Pressure/Hold Valve to Closed.
Turn the pump timer off.
Disconnect the hose at the Evap Canister that goes to the Fuel Tank.
Did the pressure drop when the hose was disconnected?
Ye s>>
Go To 5
No>>
Repair the obstruction in the Evap System between the Evap Canister and thefuel tank.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
5.EVAP CANISTER FUNCTION
NOTE: Connect all previously disconnected hoses.
Re-pressurize the Evap System. On Miller Tool #6872A, set the Pressure/Hold switch to Open and set the Vent
switch to Closed.
Turn the pump timer On and watch the gauge.
When the gauge pressure reaches 14” H2O, turn the Pressure/Hold Valve Closed.
Turn the pump timer off.
P1492-AMBIENT/BATTERY TEMPERATURE SENSOR VOLTAGE TOO HIGH
For a complete wiring diagramRefer to Section 8W.