
TEST ACTION APPLICABILITY
8 Turn the ignition off.
Disconnect the A/C Pressure Sensor harness connector.
Disconnect the PCM harness connector.
Measure the resistance of the 5 Volt Supply circuit between the A/C Pressure Sensor
harness connector and the PCM harness connector.
Is the resistance below 5 ohms?All
Ye s®Go To 9
No®Repair the 5 Volt Supply circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 2.
9 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 - 2.
10NOTE: Ensure the A/C refrigerant System is properly charges per the
Service Information.
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.
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 - 2.
No®Test Complete.
247
HEATING & A/C
P1599-A/C PRESSURE SENSOR VOLTS TOO LOW ÐContinued

TEST ACTION APPLICABILITY
15 Turn the ignition off.
Disconnect the S/C Servo harness connector.
Using a 12-volt test light connected to 12-volts, probe the ground circuit in the S/C
Servo harness connector.
Does the test light illuminate brightly?All
Ye s®Go To 16
No®Repair the ground circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER - 4.
16WARNING: 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 - 4.
No®Test Complete.
252
SPEED CONTROL
P1595-SPEED CONTROL SOLENOID CIRCUITS ÐContinued

TEST ACTION APPLICABILITY
2 Check for any open fuses in the IPM that may be related to the No Start condition.
Are any of the fuses open?All
Ye s®Using the wiring diagram/schematic as a guide, inspect the
wiring and connectors, repair as necessary. Replace the Fuse.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Go To 3
3 Turn the ignition on.
With the DRBIIIt, actuate the ASD Fuel System test.
Note: It may be necessary to use a mechanics stethoscope in the next step.
Listen for fuel pump operation at the fuel tank.
Does the Fuel Pump operate?All
Ye s®Go To 4
No®Go To 9
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.
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 5
Within Specification
Go To 7
Above Specification
Replace the fuel filter/fuel pressure regulator.
Perform POWERTRAIN VERIFICATION TEST VER-1.
Caution: Stop All Actuations.
254
STARTING
*ENGINE CRANKS DOES NOT START ÐContinued

TEST ACTION APPLICABILITY
5 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 6
Caution: Stop All Actuations.
6 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.
7Note: 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®Go To 8
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.
255
STARTING
*ENGINE CRANKS DOES NOT START ÐContinued

Symptom:
*NO CRANK CONDITION
POSSIBLE CAUSES
REPAIR MECHANICAL CONDITION
TRANSMISSION RANGE SENSOR
BATTERY CIRCUIT RESISTANCE TOO HIGH
IGNITION SWITCH OUTPUT CIRCUIT OPEN
STARTER RELAY CONTROL CIRCUIT OPEN
STARTER RELAY OUTPUT CIRCUIT OPEN
FUSED B(+) CIRCUIT OPEN
STARTER
STARTER MOTOR RELAY
STARTER RELAY
TEST ACTION APPLICABILITY
1WARNING: MAKE SURE THE BATTERY IS DISCONNECTED, THEN WAIT
TWO MINUTES BEFORE PROCEEDING.
Turn the engine over by hand to ensure the engine is not seized.
Is the engine able to turn over?All
Ye s®Go To 2
No®Repair the mechanical condition preventing the starter motor
from cranking.
Perform POWERTRAIN VERIFICATION TEST VER-1.
2 Turn the ignition off.
Disconnect the PCM harness connectors.
Move the Gear selector through all gear positions, from Park to 1st and back.
While moving the gear selector through each gear, measure the resistance between
ground and the P/N Position Switch Sense circuit.
Did the resistance change from above 10.0 ohms to below 10.0 ohms?All
Ye s®Go To 3
No®Replace the Transmission Range Sensor.
Perform POWERTRAIN VERIFICATION TEST VER-1.
3 Turn the ignition off.
Check the Battery Cables for high resistance using the service information proce-
dure.
Did either Battery Cable have a voltage drop greater than 0.2 volt?All
Ye s®Repair the Battery circuit for high resistance.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Go To 4
258
STARTING

TEST ACTION APPLICABILITY
4 Turn ignition off.
Remove the Starter Relay from PDC.
WARNING: The Parking Brake must be on and the Transmission must be in
park for a vehicle equipped with an automatic transmission.
Warning: The engine may be cranked in the next step. Keep away from
moving engine parts.
Briefly connect a jumper wire between Starter Relay B+ circuit and the Starter Relay
Output Circuits.
Did the Starter Motor crank the engine?All
Ye s®Go To 5
No®Go To 8
5 Turn the ignition off.
Remove the Starter Relay from the PDC.
Turn the ignition on.
Using a 12-volt test light, probe the Ignition Switch Output circuit in the Starter
Relay connector.
While observing 12-volt test light, hold ignition key in the start position.
Does the test light illuminate brightly?All
Ye s®Go To 6
No®Repair the Ignition Switch Output circuit for an open or high
resistance.
Perform POWERTRAIN VERIFICATION TEST VER-1.
6 Turn the ignition off.
Remove the Starter Relay from the PDC.
Disconnect the PCM harness connector.
Measure the Starter Relay Control circuit between the Relay terminal and the PCM
harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 7
No®Repair the Starter Relay Control circuit for an open.
Perform POWERTRAIN VERIFICATION TEST VER-1.
7 Turn the ignition off.
Install a substitute a Relay in the of the Starter Motor Relay.
Attempt to start the vehicle.
Does the engine crank over?All
Ye s®Replace the Starter Motor Relay.
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER-1.
259
STARTING
*NO CRANK CONDITION ÐContinued

TEST ACTION APPLICABILITY
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.
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 4
Within Specification
Go To 6
Above Specification
Replace the fuel filter/fuel pressure regulator.
Perform POWERTRAIN VERIFICATION TEST VER-1.
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.
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 5
Caution: Stop All Actuations.
5 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.
263
STARTING
*START AND STALL CONDITION ÐContinued

TEST ACTION APPLICABILITY
6Note: 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®Go To 7
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.
7 Turn the ignition on.
With the DRBIIIt, read TPS VOLTS.
While monitoring the DRBIIIt, slowly open and close the Throttle.
Is the voltage change smooth?All
Ye s®Go To 8
No®Replace the Throttle Position Sensor.
Perform POWERTRAIN VERIFICATION TEST VER-1.
8 Turn the ignition on.
With the DRBIIIt, read Throttle Position voltage. Throttle must be against stop.
Is the voltage 0.92 or less with the Throttle closed?All
Ye s®Go To 9
No®Check for a binding throttle condition. If OK, replace the Throttle
Position Sensor.
Perform POWERTRAIN VERIFICATION TEST VER-1.
264
STARTING
*START AND STALL CONDITION ÐContinued