
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.
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.
3 Visually inspect the CKP wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the CKP wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Ensure the Crankshaft Position Sensor properly installed and the mounting bolt(s)
tight.
Refer to any TSB that may apply.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 4
4 Turn the ignition off.
Remove the Crankshaft Position Sensor.
Inspect the Tone Wheel/Flex Plate slots for damage, foreign material, or excessive
movement.
Were any problems found?All
Ye s®Repair or replace the Tone Wheel/Flex Plate as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 5
5 If there are no possible causes remaining, view repair. All
Repair
Replace the Crankshaft Position Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
206
DRIVEABILITY - GAS
P1398-MIS-FIRE ADAPTIVE NUMERATOR AT LIMIT ÐContinued

TEST ACTION APPLICABILITY
2 To continue testing you will need Miller Tools #6872A Evap System Pressure Pump
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 lighted cigarettes, sparks, flames, and other ignition sources
away 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% & 80% of full to properly test
the Evap system.
Attach the power source red clip of Miller Tool #6872A to Battery (+) and the ground
black clip 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 vehicle. Install gas cap to Miller Tool
#8382. Attach the pressure 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. 209Hg) to the Leak Detection Pump. A vacuum
pump such as an A/C recovery unit works well.
Turn the ignition on.
With the DRBIIItin System Tests, select Leak Detect Pump Test. Read instructions
and then press Enter. Select: #3 - HOLD PSI.
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 149H2O, 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?All
Ye s®Go To 3
No®Repair obstruction in the EVAP system between the EVAP
Canister and the fuel tank.
Perform POWERTRAIN VERIFICATION TEST VER - 6.
3Note: All previously disconnected hose(s) reconnected.
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 149H2O, turn the Pressure/Hold Valve to Closed.
Turn the pump timer off.
Disconnect the LDP Pressure hose at the EVAP Canister. The LDP Pressure hose is
the hose that connects the Evap Canister to the Leak Detection Pump.
Did the pressure drop when the hose was disconnected?All
Ye s®Go To 4
No®Replace the EVAP Canister.
Perform POWERTRAIN VERIFICATION TEST VER - 6.
208
DRIVEABILITY - GAS
P1486-EVAP LEAK MONITOR PINCHED HOSE FOUND ÐContinued

TEST ACTION APPLICABILITY
3WARNING: 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.
4 Turn the ignition off.
Disconnect the Radiator Fan Relay harness connector.
Using a 12-volt test light connected to 12-volts, probe the Ground circuit in the
Radiator Fan Relay harness connector.
Does the test light illuminate?All
Ye s®Go To 5
No®Repair the Ground circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
5NOTE: Inspect the Radiator Fan fuse located in the IPM.
Turn the ignition off.
Disconnect the Radiator Fan Relay harness connector.
Measure the voltage of the Fused B+ Output circuit in the Radiator Fan Relay
harness connector.
Is the voltage above 11.0 volts?All
Ye s®Go To 6
No®Repair the Fused B+ circuit. Check and replace any open fuses.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
6NOTE: Ensure the Radiator Fan Relay harness connector is connected.
Turn the ignition off.
Disconnect the PCM harness connector.
Turn the ignition on.
Using a jumper wire, momentarily jumper the Radiator Fan Relay Control circuit to
ground.
Did the Radiator Fans operate?All
Ye s®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 7
211
DRIVEABILITY - GAS
P1491-RAD FAN CONTROL RELAY CIRCUIT ÐContinued

TEST ACTION APPLICABILITY
6 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Throttle Position Sensor harness connector.
Disconnect the MAP Sensor harness connector.
Disconnect the PCM harness connectors.
Disconnect the A/C Pressure Sensor harness connector.
Disconnect the EGR Solenoid harness connector.
Measure the resistance of the 5 Volt Supply circuit in the Throttle Position Sensor
harness connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the 5 Volt Supply Circuit for a short to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 7
7 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.
8NOTE: The Throttle Position Sensor harness connector must be connected
during this test.
Disconnect the MAP Sensor harness connector.
Turn the ignition on.
Measure the 5 Volt Supply circuit in the MAP Sensor harness connector.
Is the Voltage below 4.5 Volts?All
Ye s®Replace the Throttle Position Sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 9
9WARNING: 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.
220
DRIVEABILITY - GAS
P1496-5 VOLT SUPPLY, OUTPUT TOO LOW ÐContinued

TEST ACTION APPLICABILITY
2 Turn the ignition off.
WARNING: The fuel system is under a constant pressure even with the
engine off. Before testing or servicing any fuel system hose, fitting or line,
the fuel system pressure must be released.
Install a fuel pressure gauge to the fuel rail test port.
Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test and observe the fuel pressure
gauge.
NOTE: Fuel pressure specification is 400 KPa +/- 34 KPa (58 psi +/- 5 psi).
Choose a conclusion that best matches your fuel pressure reading.All
Below Specification
Go To 3
Within Specification
Go To 5
Above Specification
Replace the fuel filter/fuel pressure regulator.
Perform POWERTRAIN VERIFICATION TEST VER-1.
Caution: Stop All Actuations.
3 Turn the ignition off.
WARNING: The fuel system is under a constant pressure even with the
engine off. Before testing or servicing any fuel system hose, fitting or line,
the fuel system pressure must be released.
Raise vehicle on hoist, and disconnect the fuel pressure line at the fuel pump module.
Install special 5/169fuel line adapter tool #6539 between disconnected fuel line and
the fuel pump module.
Attach a fuel pressure test gauge to the9T9fitting on tool #6539.
Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test and observe the fuel pressure
gauge.
NOTE: Fuel pressure specification is 400 KPa +/- 34 KPa (58 psi +/- 5 psi).
Is the fuel pressure within specification now?All
Ye s®Repair/replace fuel supply line as necessary.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Go To 4
Caution: Stop All Actuations.
4 Turn the ignition off.
WARNING: The fuel system is under a constant pressure even with the
engine off. Before testing or servicing any fuel system hose,fitting or line,
the fuel system pressure must be released.
Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?All
Ye s®Replace the Fuel Pump Inlet Strainer.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Replace the Fuel Pump Module.
Perform POWERTRAIN VERIFICATION TEST VER-1.
228
DRIVEABILITY - GAS
*CHECKING FUEL DELIVERY ÐContinued

TEST ACTION APPLICABILITY
5Note: The fuel pressure must be within specification before continuing.
Turn the ignition off.
WARNING: The fuel system is under a constant pressure even with the
engine off. Before testing or servicing any fuel system hose, fitting or line,
the fuel system pressure must be released.
Disconnect the fuel supply line at the fuel rail.
Connect fuel line adapter #6539(5/169) or #6631(3/89) to the disconnected fuel supply
line. Insert the other end of the adapter into a graduated container.
Caution: Do not operate the fuel pump for more than 7 seconds in the next
step. Fuel pump module reservoir may run empty and damage to the fuel
pump will result.
Note: Specification: A good fuel pump will deliver at least 1/4 liter (1/2 pint)
of fuel in 7 seconds.
Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test for 7 seconds.
Is the fuel pump capacity within specification?All
Ye s®Test Complete.
No®Check for a kinked/damaged fuel supply line between the fuel
tank and fuel rail. If OK, replace the fuel pump module.
Perform POWERTRAIN VERIFICATION TEST VER-1.
Caution: Stop All Actuations.
6 Turn the ignition off.
Disconnect the fuel pump module harness connector.
Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test.
Using a 12 volt test light connected to ground, probe the Fuel Pump Relay Output
circuit at the Fuel Pump Module harness connector.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Go To 9
Caution: Stop All Actuations.
7 Turn the ignition off.
Disconnect the Fuel Pump Module harness connector.
Note: Check connectors - It is critical that the connector is free from any
signs of corrosion or deformities - Clean/repair as necessary.
Using a test light connected to battery voltage, probe the Fuel Pump ground circuit
at the Fuel Pump Module harness connector.
Does the test light illuminate brightly?All
Ye s®Go To 8
No®Repair the open/high resistance in the fuel pump ground circuit.
Perform POWERTRAIN VERIFICATION TEST VER-1.
8 If there are no possible causes remaining, view repair. All
Repair
Replace the Fuel Pump Module.
Perform POWERTRAIN VERIFICATION TEST VER-1.
229
DRIVEABILITY - GAS
*CHECKING FUEL DELIVERY ÐContinued

TEST ACTION APPLICABILITY
3WARNING: KEEP CLEAR OF THE ENGINE'S MOVING PARTS.
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.
4 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Fused Ignition Switch
circuit in the IPM.
Does the test light illuminate?All
Ye s®Go To 5
No®Go To 10
5 Turn the ignition off.
Remove the A/C Clutch Relay from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay circuit in
the IPM.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light flash on and off?All
Ye s®Replace the A/C Clutch Relay.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 6
6 Turn the ignition off.
Disconnect the Intelligent Power Module C3 harness connector.
Turn the ignition on.
Using a 12-volt test light connected to 12-volts, probe the A/C Clutch Relay Control
circuit in the IPM harness connector.
With the DRBIIIt, actuate the A/C Clutch Relay.
Does the test light flash on and off?All
Ye s®Replace the IPM Fused & Relay Center.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 7
240
HEATING & A/C
P0645-A/C CLUTCH RELAY CKT ÐContinued

TEST ACTION APPLICABILITY
8NOTE: Ensure the A/C refrigerant System is properly charged per the
Service Information.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
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.
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 - 2.
No®Test Complete.
244
HEATING & A/C
P1598-A/C PRESSURE SENSOR VOLTS TOO HIGH ÐContinued