
3.(A109) FUEL PUMP CONTROL OUTPUT CIRCUIT SHORTED TO GROUND
Turn the ignition off
Disconnect the C10 TIPM harness connector.
Disconnect the Fuel Pump Module harness connector.
Measure the resistance between ground and the (A109) Fuel Pump
Control Output circuit at the Fuel Pump Module harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (A109) Fuel Pump Control
Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.FUEL PUMP MODULE
Connect the C1 and C10 TIPM harness connectors.
Ignition on, engine not running.
Using the scan tool under the TIPM Actuators, actuate the Fuel Pump.
With a 12-volt test light connected to ground, probe the (A109) Fuel
Pump Control Output circuit at the Fuel Pump Module harness connec-
tor.
Does the test light illuminate brightly and flash on and off?
Ye s>>
Replace the Fuel Pump Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.TOTALLY INTEGRATED POWER MODULE
NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors.
Pay particular attention to all Power and Ground circuits.
Were any problems found?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace the Totally Integrated Power Module per Service Information.
Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES - STANDARD PROCEDURE)

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)

4.ASD RELAY
Install a substitute relay for the ASD Relay.
Attempt to startthe vehicle.
Did the engine start?
Ye s>>
Replace the ASD Relay.
Perform POWERTRAIN VERIFICATION TEST VER - 2.
No>>
Go To 5
5.(A14) FUSED B+ CIRCUITS
Turn the ignition off.
Remove the ASD Relay from the PDC.
Using a 12-volt test light, probe the (A14) Fused B+ circuits at the ASD Relay connector in the PDC.
Does the test light illuminate brightly?
Ye s>>
Go To 6
No>>
Repair the open or short to ground in the (A14) Fused B+ circuits. Inspect the related fuse and repair
as necessary.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
6.(K342) ASD RELAY OUTPUT CIRCUIT OPEN
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)
7.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

3.(K125) GENERATOR SOURCE CIRCUIT OPEN
Turn the ignition off.
Disconnect the Leak Detection Pump electrical harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Leak Detection Pump.
Using a 12-volt test light connected to ground, check the (K125) Gen-
erator Source circuit at the LDP connector.
Does the test light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open in the (K125) Generator Source circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
4.LDP SOLENOID CONTROL OPERATION
Turn the ignition off.
Connect a 12-volt test light to a good 12-volt source.
Ignition on, engine not running.
With the scan tool, actuate the Leak Detection Pump.
Probe the (K106) LDP Solenoid Control circuit with the test light while
the Pump is actuating.
Does the test light blink?
Ye s>>
Go To 5
No>>
Go To 8

When Monitored:
With the ignition key on and the engine speed greater than 0 RPM.
Set Condition:
When the PCM regulates the generator field and there are no detected field problems, but the voltage output
does not decrease.
Possible Causes
(K20) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND
GENERATOR FIELD COIL SHORTED TO GROUND
BATTERY TEMPERATURE SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.CHARGING SYSTEM OPERATION
NOTE: Battery must be fully charged and be capable of passing a load test.
NOTE: Generator Belt tension and condition must be checked before continuing.
Ignition on, engine not running.
With the scan tool, read DTCs and the related Freeze Frame data then clear theDTCs.
With scan tool, actuate the Generator Field Driver.
With a 12-volt test light connected to ground, backprobe the (K20) Gen Field Control circuit in the back of Generator
Field harness connector.
Does the test light illuminate brightly and flash?
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.(K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Disconnect the Generator Field Harness connector.
Carefully inspect the related connectors for corrosion or spread termi-
nals before continuing.
Measure the resistance between ground and the (K20) Generator Field
Driver circuit at the Generator Field harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K20) Generator Field
Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3

Possible Causes
(A103) FUSED B+ CIRCUIT
(Z429) BRAKE LAMP SWITCH GROUND CIRCUIT OPEN
BRAKE LAMP SWITCH
(B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT OPEN
(B29) BRAKE SWITCH NO.1 SIGNAL CIRCUIT SHORT TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.SCAN TOOL DOES NOT SHOW BRAKE SW PRESSED OR RELEASED
Ignition on, engine not running.
With the scan tool in Inputs/Outputs, read the Brake Switch state.
While observing the scan tool display, press and release the brake pedal several times.
Does the scan tool display Brake Switch PRESSED and RELEASED?
Ye s>>
The Brake Lamp Switch is operating properly at this time.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.(A103) FUSED B+ CIRCUIT OPEN
Turn the ignition off.
Disconnect the Brake Lamp Switch harness connector.
Using a 12-volt test light connected to ground, probe the (A103) Fused
B+ circuit at the Brake Lamp Switch harness connector.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the open or short to ground in the (A103) Fused B+
circuit. Check and replace fuses as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)

6.(B29) BRAKE LAMP SWITCH SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (B29) Brake Lamp
Switch Signal circuit at the Stop Lamp Switch harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (B29) Brake Lamp Switch
Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 7
7.(B29) BRAKE LAMP SWITCH SIGNAL LESS THAN 10.0 VOLTS
Connect the PCM harness connectors.
Connect the Brake Lamp Switch harness connector.
Brake pedal must be depressed in the next step.
Ignition on, engine not running.
Using a 12-volt test light connected to ground, probe the (B29) Brake Lamp Switch Signal circuit at the Brake Lamp
Switch harness connector.
Is the test light illuminated and bright?
Ye s>>
Go To 8
No>>
Replace or adjust the brake switch.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
8.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

4.REFRIGERATION SYSTEM NOT PROPERLY CHARGED
Turn the ignition off.
Verify that the Refrigerant System is properly charged per Service Procedure.
Is the Refrigerant System properly charged?
Ye s>>
Go To 5
No>>
Properly charge the Refrigerant System per Service Information.
Perform BODY VERIFICATION TEST - VER 1.
5.HIGH PRESSURE CUT-OFF SWITCH
Turn the ignition off.
Verify the High Pressure Cut-Off Switch operation per Service Information.
Is the High Pressure Cut-Off Switch OK?
Ye s>>
Go To 6
No>>
Replace the High Pressure Cut-Off Switch.
Perform BODY VERIFICATION TEST - VER 1.
6.LOW PRESSURE SWITCH
Turn the ignition off.
Verify the Low Pressure Switch operation per Service Information.
Is the Low Pressure Switch OK?
Ye s>>
Go To 7
No>>
Replace the Low Pressure Switch.
Perform BODY VERIFICATION TEST - VER 1.
7.A/C CLUTCH COIL
Ignition on, engine not running.
Disconnect the A/C Compressor Clutch harness connector.
Connect a test light between the ground circuit and the A/C Clutch Relay Output circuit.
With the scan tool, actuate the A/C Clutch Relay.
Does the test light illuminate brightly on and off with the relay actuation?
Ye s>>
Replace the A/C Clutch Coil.
Perform BODY VERIFICATION TEST - VER 1.
No>>
Go To 8
8.A/C COMPRESSOR CLUTCH GROUND CIRCUIT OPEN
Turn the ignition off.
Disconnect the A/C Clutch harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between ground and the A/C Compressor Clutch ground circuit in the A/C Clutch harness
connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair the open in the A/C Compressor Clutch ground circuit.
Perform BODY VERIFICATION TEST - VER 1.