
Symptom:
* CHECKING THROTTLE POSITION SENSOR CALIBRATION
POSSIBLE CAUSES
TPS VOLTAGE CHANGE NOT A SMOOTH TRANSITION
TPS VOLTAGE ABOVE 1.5 V WITH THROTTLE CLOSED
THROTTLE CABLE AND BODY BINDING OR RESTRICTED
TPS VOLTAGE BELOW 3.4 V AT WIDE OPEN THROTTLE
TEST ACTION APPLICABILITY
1 Ignition Off
Check the Throttle Cable and Body for binding or restrictions.
Note: Also check Speed Control Cable if equipped.
Is there any binding or restriction?All
Ye s®Repair as necessary.
Perform Verification Test VER-2A.
No®Go To 2
2 Ignition On, Engine Not Running
While slowly opening the Throttle from closed to wide open, monitor the Throttle
Position Sensor voltage at the DRB.
Was the voltage change a smooth transition?All
Ye s®Go To 3
No®Replace Throttle Position Sensor.
Perform Verification Test VER-2A.
3 Ignition On, Engine Not Running
With the DRB, read the Throttle Position Sensor voltage.
Note: Throttle must be fully closed and against the Throttle Stop.
Is the voltage 1.5 V or less with the Throttle closed?All
Ye s®Go To 4
No®Replace Throttle Position Sensor.
Perform Verification Test VER-2A.
4 Was the maximum voltage at least 3.4 volts at wide open Throttle? All
Ye s®Test Complete.
No®Replace Throttle Position Sensor.
Perform Verification Test VER-2A.
254
DRIVEABILITY
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Symptom:
* CHECKING THE A/C PRESSURE SENSOR SIGNAL
POSSIBLE CAUSES
A/C PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT OPEN
HIGH RESISTANCE IN THE A/C PRESSURE SENSOR SIGNAL CKT
TEST ACTION APPLICABILITY
1 Turn the ignition on.
Using the DRB, read the trouble codes.
Are any A/C Pressure sensor trouble codes set?All
Ye s®Go to the A/C Pressure sensor trouble code.
No®Go To 2
2 Turn the ignition off.
Disconnect the A/C Pressure Sensor harness connector.
Turn the ignition on.
Using a voltmeter, measure the A/C Pressure Sensor 5±volt supply circuit.
Is the voltage above 4.8 volts?All
Ye s®Go To 3
No®Repair the open in the A/C Pressure Sensor 5±volt supply circuit.
Perform Powertrain Verification Test VER-2A.
3 Turn the ignition on.
Using the DRB, monitor the A/C Pressure voltage.
Disconnect the A/C Pressure Sensor harness connector.
Is the voltage above 4.8 volts?All
Ye s®Test Complete.
No®Repair the high resistance in the A/C Pressure Sensor Signal
circuit.
Perform Powertrain Verification Test VER-2A.
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DRIVEABILITY
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TEST ACTION APPLICABILITY
9 Ignition Off.
Connect the DRB to a functional Data Link Connector on another vehicle.
Turn the ignition on.
With the DRB, attempt to read trouble codes.
Did the DRB display ªNo Responseº?All
Ye s®Go To 10
No®Replace the initial vehicle's Powertrain Control Module.
Perform Powertrain Verification Test VER-1A.
10 Ignition Off.
Substitute another DRB Adapter Cable.
Ignition on, Engine not running.
With the DRB, attempt to read trouble codes.
Did the DRB display ªNo Responseº?All
Ye s®Go To 11
No®Replace the DRB Adapter Cable.
Perform Powertrain Verification Test VER-1A.
11 If there are no potential causes remaining, the Diagnostic Readout Box is assumed to
be defective.
View repair options.All
Repair
Have the DRB repaired or replaced.
Perform Powertrain Verification Test VER-1A.
12 Ignition Off.
Disconnect the TP Sensor Connector.
Note: Check connector-Clean/repair as necessary.
Turn the ignition on.
With a voltage, measure the Throttle Position Sensor 5±volt Supply circuit.
Is the voltage above 6.0 volts?All
Ye s®Repair the open grounds at the Powertrain Control Module
Cavities 10 and 50.
Perform the Powertrain Verification Test VER-1A
No®Go To 13
13 Ignition Off.
Disconnect the Powertrain Control Module.
Note: Check connector-Clean/repair as necessary.
Turn the ignition on.
With a voltmeter, measure Fused Ignition Switch Output Circuit.
Is the voltage above 10.0 volts?All
Ye s®Go To 14
No®Repair the open Fused Ignition Switch Output Circuit (check
Ignition Switch Fuse in PDC).
Perform Powertrain Verification Test VER-1A.
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*(NO RESPONSE(CONDITION ÐContinued
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Symptom:
* CHECKING THE CAM AND CRANK SENSORS
POSSIBLE CAUSES
SECONDARY INDICATORS PRESENT
TEST ACTION APPLICABILITY
1 Ignition On, Engine Not Running
Note: Address all trouble codes before continuing.
Note: Ensure PCM Connectors are secure.
With the DRB, read the secondary indicators while cranking the engine.
Were there any secondary indicators present while cranking the engine?All
Ye s®Refer to Symptom list for further diagnostic test.
No®Go To 2
2 Ignition On, Engine Not Running
With the DRB in Input/Output display, monitor the current CMP and CKP states.
Crank the engine for at least 15 seconds.
Does the DRB show current CKP state9present9while cranking?All
Ye s®Go To 3
No®Refer to symptom P-0340 NO CRANK REFERENCE SIGNAL AT
PCM in the DRIVEABILITY category.
3 Ignition On, Engine Not Running
With the DRB in Input/Output display, monitor the current CMP and CKP states.
Crank the engine for at least 15 seconds.
Does the DRB show current CMP state9present9while cranking?All
Ye s®Refer to symptom * CHECKING THE SECONDARY IGNITION
SYSTEM in the STARTING category.
No®Refer to symptom P-0340 NO CAM SIGNAL AT PCM in the
DRIVEABILITY category.
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Symptom:
* CHECKING THE FUEL SYSTEM
POSSIBLE CAUSES
FUEL PUMP GROUND CIRCUIT OPEN
FUEL PUMP GROUND CIRCUIT OPEN
FUEL PUMP RELAY FUSED B(+) CIRCUIT OPEN
FUEL PUMP RELAY FUSED B(+) CIRCUIT OPEN
FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
FUEL PUMP RELAY OUTPUT CIRCUIT OPEN
FUEL FILTER DEFECTIVE
FUEL FILTER DEFECTIVE
FUEL PUMP DEFECTIVE
FUEL PUMP DEFECTIVE
FUEL PUMP RELAY
FUEL PUMP RELAY
IN-TANK FUEL PRESSURE REGULATOR DEFECTIVE
IN-TANK FUEL PRESSURE REGULATOR DEFECTIVE
THROTTLE POSITION SENSOR DEFECTIVE
FUEL FILTER DEFECTIVE
FUEL FILTER DEFECTIVE
FUEL INLET STRAINER DEFECTIVE
FUEL INLET STRAINER DEFECTIVE
FUEL PUMP MODULE DEFECTIVE
FUEL PUMP MODULE DEFECTIVE
FUEL SUPPLY LINE DEFECTIVE
FUEL SUPPLY LINE DEFECTIVE
FUEL TUBE RESTRICTED
FUEL TUBE RESTRICTED
POWERTRAIN CONTROL MODULE DEFECTIVE
POWERTRAIN CONTROL MODULE DEFECTIVE
THROTTLE CABLES DEFECTIVE
THROTTLE CABLES DEFECTIVE
THROTTLE POSITION SENSOR DEFECTIVE
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TEST ACTION APPLICABILITY
1Note: Ensure the SKIM has proper communication and that there are no
SKIM DTC's present before continuing.
Ignition Off.
Ensure the Throttle Cables are not holding the Throttle open.
Is the Throttle held open?ENGINE - 3.0L V6
Ye s®Repair condition that holds the Throttle Body open.
Perform Powertrain Verification Test VER-1A.
No®Go To 2
2 Ignition On, Engine Not Running
With the DRB, actuate the Fuel System and check for Fuel Pump operation at the
Fuel Tank.
Is the Fuel Pump operating?ENGINE - 3.0L V6
Ye s®Go To 3
No®Go To 13
3 Ignition On, Engine Not Running
With DRB, read Throttle Position Sensor voltage.
Is the voltage above 1.5 volts?ENGINE - 3.0L V6
Ye s®Disconnect the TP Sensor Conn. Replace Throttle Position Sensor.
Perform Powertrain Verification Test VER-1A.
No®Go To 4
4 Ignition Off.
Warning: The Fuel System must be opened and may be under high pressure.
Relieve Fuel pressure.
Install a Fuel Pressure Gauge to the Fuel Rail.
Note: The Fuel Tank must be at least 1/4 full for the following tests.
Ignition On, Engine Not Running.
With the DRB, actuate the Fuel System.
Read the Fuel Pressure Gauge.
Fuel pressure should be 43 to 53 psi for Gasoline.
Is the Fuel pressure above the specification ?ENGINE - 3.0L V6
Ye s®Go To 5
No®Go To 8
5 Ignition Off.
Warning: The Fuel System must be opened and may be under high pressure.
Release the Fuel pressure.
Inspect Fuel Filter for a restriction.
Is there a restriction?ENGINE - 3.0L V6
Ye s®Replace the Fuel Filter.
Perform Powertrain Verification Test VER-1A.
No®Go To 6
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* CHECKING THE FUEL SYSTEM ÐContinued
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TEST ACTION APPLICABILITY
10 Ignition Off.
Warning: The Fuel System must be opened and may be under high pressure.
Release Fuel pressure.
Remove the Fuel Pump Module.
Inspect the Fuel Pump Inlet Strainer.
Is the Inlet Strainer plugged?ENGINE - 3.0L V6
Ye s®Replace the Fuel Inlet Strainer.
Perform Powertrain Verification Test VER-1A.
No®Go To 11
11 Record the Fuel Pressure Gauge reading.
Ignition key off.
Warning: The Fuel System must be opened and may be under high pressure.
Release Fuel pressure.
Remove the Fuel Pressure Gauge.
Remove Fuel Pressure Gauge Adapter 6433 and reconnect Fuel Line to Fuel Rail.
Install adapter 6631 between Fuel Filter Outlet and Chassis Fuel Supply Tube.
Connect Fuel Pressure Gauge to adapter 6631.
Ignition On, Engine Not Running.
With DRB, actuate the ASD Fuel System.
Record the Fuel Pressure Gauge reading.
Compare this reading with the previous reading.
Is the fuel pressure at least 2 psi higher than the previous reading?ENGINE - 3.0L V6
Ye s®Repair restriction in Chassis Fuel Supply Line between Fuel
Filter and Fuel Rail.
Perform Powertrain Verification Test VER-1A.
No®Go To 12
12 If there are no potential causes remaining, the Fuel Pump Module is assumed to be
defective.
View repair options.ENGINE - 3.0L V6
Repair
Replace Fuel Pump Module.
Perform Powertrain Verification Test VER-1A.
13 Ignition On, Engine Not Running
With DRB, read Throttle Position Sensor voltage.
Is the voltage above 1.5 volts?ENGINE - 3.0L V6
Ye s®Disconnect the TP Sensor Conn. Replace Throttle Position Sensor.
Perform Powertrain Verification Test VER-1A.
No®Go To 14
14 Ignition Off.
Disconnect the Fuel Pump Harness Connector.
Note: Check connectors - Clean/repair as necessary.
Caution: It is critical that the Fuel Pump Connector has a clean and tight
connection.
With an Ohmmeter, measure the Fuel Pump Ground Circuit.
Is the resistance below 5.0 ohms?ENGINE - 3.0L V6
Ye s®Go To 15
No®Repair the open Fuel Pump Ground Circuit.
Perform Powertrain Verification Test VER-1A.
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* CHECKING THE FUEL SYSTEM ÐContinued
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TEST ACTION APPLICABILITY
3 Ignition Off
Check Transmission Fluid level and ensure it is clear of any debris.
Is the Transmission Fluid okay?TRANSMISSION -
AUTOMATIC
3-SPD, 31TH
Ye s®Go To 4
No®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
4 Ignition Off
Disconnect the TCC Solenoid connector.
Note: Check connectors - Clean/repair as necessary.
Turn key on.
Use a Voltmeter in the following step.
Using a Voltmeter, measure the Fused Ignition Switch Output Circuit at Solenoid
Connector.
Is the voltage above 10.0 volts?TRANSMISSION -
AUTOMATIC
3-SPD, 31TH
Ye s®Go To 5
No®Repair the open Fused Ignition Switch Output Circuit.
Perform Powertrain Verification Test VER-5A.
5 Ignition Off
Disconnect the TCC Solenoid connector.
Note: Check connectors - Clean/repair as necessary.
With an Ohmmeter, measure across the Solenoid for resistance.
Was resistance between 30.0 and 50.0 ohms?TRANSMISSION -
AUTOMATIC
3-SPD, 31TH
Ye s®Go To 6
No®Replace TCC Solenoid.
Perform Powertrain Verification Test VER-5A.
6 Drive Vehicle
Maintain 50 MPH per DRB. Wait 10 seconds in lockup. Record Engine RPM.
Was engine RPM 2200 +/- 50 RPM?TRANSMISSION -
AUTOMATIC
3-SPD, 31TH
Ye s®Go To 7
No®Inspect Differential, Output Shaft, or Gear Box. Refer to service
instructions for proper diagnosis.
Perform Powertrain Verification Test VER-5A.
7 Ignition Off
Remove VSS.
Note: Check connectors - Clean/repair as necessary.
Inspect sensor and gear for damage, also improper wheel size.
Were any problems found?TRANSMISSION -
AUTOMATIC
3-SPD, 31TH
Ye s®Repair as necessary.
Perform Powertrain Verification Test VER-5A.
No®Test Complete.
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TRANSMISSION
P-0740 TORQUE CONV CLUTCH, NO RPM DROP AT LOCKUP ÐContinued
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