*HARD START FUEL SYSTEM
For a complete wiring diagramRefer to Section 8W.
Possible Causes
FUEL CONTAMINATION
RESTRICTED FUEL SUPPLY LINE
FUEL PUMP INLET STRAINER PLUGGED
FUEL PUMP MODULE
FUEL INJECTOR(S)
Diagnostic Test
1.CHECKING FUEL PRESSURE
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Install a fuel pressure gauge at the engine.
Ignition on, engine not running.
With a scan tool, actuate the ASD Fuel System test and observe the fuel pressure gauge.
NOTE: NOTE: Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Choose a conclusion that best matches your fuel pressure reading.
Below Specification
Go To 2
Within Specification
Go To 4
2.RESTRICTED FUEL SUPPLY LINE
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Raise vehicle on hoist, and disconnect the fuel supply line at the fuel pumpmodule.
Install special tool #6539 (5/16
) #6631(3/8) fuel line adapter and the fuel pressure gauge between the fuel supply
line and the fuel pump module.
Ignition on, engine not running.
With the scan tool, actuate the ASD FuelSystem test and observe the fuel pressure gauge.
NOTE: Fuel pressure specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Is the fuel pressure within specification?
Ye s>>
Visually and physically inspect the fuel supply lines between the fuel tank and the fuel rail. Repair/re-
place as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.CHECKING THE FUEL INLET STRAINER
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Remove the Fuel Pump Module and inspect the Fuel Inlet Strainer.
Is the Fuel Inlet Strainer plugged?
Ye s>>
Replace the Fuel Pump Inlet Strainer.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Replace the Fuel Pump Module.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
4.FUEL PUMP MODULE
NOTE: Before continuing visually and physically inspect the fuel delivery system for external leaks or dam-
age. Repair / replace as necessary.
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Install special tool #6539 (5/16
) or #6631 (3/8) fuel line adapter.
Install the fuel pressure gauge.
Start the engine and allow the fuel system to reach maximum pressure.
Turn the ignition off.
NOTE: Fuel specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Using special tool #C4390, Hose Clamp Pliers, pinch the rubber fuel line between the fuel pressure gauge and the
engine.
Monitor the fuel pressure gauge for a minimum of 5 minutes.
NOTE: The pressure should not fall below 241 KPa (35 psi)
Does the fuel pressure drop?
Ye s>>
Replace Fuel Pump Module.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.FUEL INJECTOR(S)
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Remove special tool #C4390.
Start the engine and allow the fuel system to reach maximum pressure.
Turn the ignition off.
NOTE: Fuel specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Move special tool #C4390, Hose Clamp Pliers, from between the fuel pressure gauge and the engine to between
the fuel pressure gauge and fuel pump module.
Monitor the fuel pressure gauge for a minimum of 5 minutes.
3.SECONDARY INDICATORS PRESENT
Ignition on, engine not running.
With the scan tool, under DTCs & Related Functions, read the Secondary Indicators while cranking the engine.
Are there any Secondary Indicators present while cranking the engine?
Ye s>>
Refer to the Engine Electrical Diagnostics group and perform the tests related to the secondary indicator
that is reported by the scan tool.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.ENGINE MECHANICAL
Check for any of the following conditions/mechanical problems.
ENGINE VALVE TIMING - must be within specifications, check for broken timing components
ENGINE COMPRESSION - must be within specifications
ENGINE EXHAUST SYSTEM - must be free of any restrictions or leaks.
Are there any engine mechanical problems?
Ye s>>
Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.(K342) ASD RELAY OUTPUT CIRCUIT OPEN
Turn the ignition off.
Remove the ASD relay from the IPM.
Disconnect the C3 PCM harness connector.
Verify the ASD Relay is getting voltageontheFusedB+circuitsbefore
continuing.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
Measure the resistance of the ASD Relay Output circuit from the ASD
Relay connector to the appropriate terminals of special tool #8815, Igni-
tion coil, and the fuel injectors.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 6
No>>
Repair the open in the (K342)ASD Relay Output circuits.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
*FUEL PRESSURE LEAK DOWN
For a complete wiring diagramRefer to Section 8W.
Possible Causes
FUEL PUMP MODULE
FUEL INJECTOR(S)
Diagnostic Test
1.FUEL PUMP MODULE
NOTE: Before continuing visually and physically inspect the fuel delivery system for external leaks or dam-
age. Repair / replace as necessary.
Turn the ignition off.
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Install special tool #6539 (5/16
) or #6631 (3/8) fuel line adapter.
Install the fuel pressure gauge.
Start the engine and allow the fuel system to reach maximum pressure.
Turn the ignition off.
NOTE: Fuel specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Using special tool #C4390, Hose Clamp Pliers, pinch the rubber fuel line between the fuel pressure gauge and the
engine.
Monitor the fuel pressure gauge for a minimum of 5 minutes.
NOTE: The pressure should not fall below 241 KPa (35 psi)
Does the fuel pressure drop?
Ye s>>
Replace Fuel Pump Module.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 2
2.FUEL INJECTOR(S)
WARNING: The fuel system is under a constant pressure (even with the engineoff). Before testing or ser-
vicing any fuel system hose, fitting or line, the fuel system pressure mustbe released. Failure to follow
these instructions can result in personal injury or death.
Remove special tool #C4390.
Start the engine and allow the fuel system to reach maximum pressure.
Turn the ignition off.
NOTE: NOTE: Fuel specification is 407 KPa +/- 34 KPa (59 psi +/- 5 psi).
Move special tool #C4390, Hose Clamp Pliers, from between the fuel pressure gauge and the engine to between
the fuel pressure gauge and fuel pump module.
Monitor the fuel pressure gauge for a minimum of 5 minutes.
NOTE: The pressure should not fall below 241 KPa (35 psi)
Does the fuel pressure drop?
Ye s>>
Replace the leaking fuel injectors.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Te s t C o m p l e t e .
Possible Causes
MECHANICAL CONDITION
BATTERY CIRCUIT RESISTANCE TOO HIGH
FUSED IGNITION SWITCH OUTPUT CIRCUITS
FUSED B+ CIRCUIT OPEN
(T752) STARTER RELAY CONTROL CIRCUIT OPEN
(T750) STARTER RELAY OUTPUT CIRCUIT OPEN
TRANSMISSION RANGE SENSOR
STARTER RELAY
STARTER
Diagnostic Test
1.MECHANICAL CONDITION
NOTE: Verify the battery is fully charged and capable of passing a load testbefore continuing.
WARNING: Make sure the battery is disconnected, then wait two minutes before proceeding. Failure to do
so may result in personal injury or possible death.
Turn the engine over by hand to make sure the engine is not seized.
Is the engine able to turn over?
Ye s>>
Go To 2
No>>
Repair the mechanical condition preventing the starter motor from cranking.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.TRANSMISSION RANGE SENSOR
Turn the ignition off.
Disconnect the TRS 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 resis-
tance between ground and the TRS (T41) Sense (P/N Position Switch
Sense) circuit at the TRS connector.
NOTE: The circuit is grounded in Park and Neutral and open in the
other positions.
Did the resistance change from above 100 kohms (open) to
below 10.0 ohms (grounded) ?
Ye s>>
Go To 3
No>>
Replace the Transmission Range Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
3.EXCESSIVE RESISTANCE IN THE BATTERY CIRCUIT
Turn the ignition off.
Check the Battery Cables for excessive resistance using the service information procedure.
Did either Battery Cable have a voltage drop greater than 0.2 of a volt?
Ye s>>
Repair the excessive resistance in the Battery circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.STARTER RELAY
Turn ignition off.
Remove the Starter Relay from IPM.
CAUTION: The Parking Brake must be on and the Transmission must be in park for a vehicle equipped with
an automatic transmission.
WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands
near the pulleys, belts, or fan. Do notwear loose clothing. Failure to follow these instructions can result in
personal injury or death.
Briefly connect a jumper wire from the Internal Fused B+ circuit to the (T750) Starter Relay Output circuit.
Did the Starter Motor crank the engine?
Ye s>>
Go To 5
No>>
Go To 7
5.(T751) FUSED IGNITION SWITCH OUTPUT CIRCUIT
Ignition on, engine not running.
Using a 12-volt test light, probe the (T751) Fused 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?
Ye s>>
Go To 6
No>>
Repair the excessive resistance in the(T751)FusedIgnitionSwitchOutput circuit. Inspect related fuses
and repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
6.(T752) STARTER RELAY CONTROL CIRCUIT OPEN
Turn the ignition off.
Remove the Starter Relay from the IPM.
Disconnect the C3 PCM harness connector.
Measure the resistance in the (T752) Starter Relay Control circuit from
the Relay terminal to the appropriate terminals of special tool #8815.
Is the resistance below 5.0 ohms?
Ye s>>
Replace the Starter Motor Relay.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Repair the open in the (T752) Starter Relay Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
7.INTERNAL FUSED B+ CIRCUIT OPEN
Turn the ignition off.
Using a 12-volt test light connected to ground, probe the Internal Fused B+circuit at the Starter Relay terminal.
Does the test light illuminate brightly?
Ye s>>
Go To 8
No>>
Repair the excessive resistance in the Internal Fused B+ circuit. Inspectrelated fuses and repair as
necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
8.(T750) STARTER RELAY OUTPUT CIRCUIT OPEN
Disconnect the Starter Relay Output connector from the Starter Sole-
noid.
Measure the resistance of the (T750) Starter Relay Output circuit
between the Relay and the Solenoid harness connector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 9
No>>
Repair the open in the Starter Relay Output circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
Possible Causes
(A919) PCM FUSED B+ CIRCUIT
PCM NO RESPONSE
(F202) (F1) (T751) PCM FUSED IGNITION SWITCH OUTPUT CIRCUITS
(Z130) (Z131) PCM GROUND CIRCUITS
CRANKSHAFT POSITION SENSOR
(F855) 5-VOLT SENSOR OPEN/SHORTED
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F856) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
PCM
Diagnostic Test
1.(A919) PCM FUSED B+ CIRCUIT
NOTE: The scan tool and cable must be operating properly for the
resultsofthistesttobevalid.
NOTE: Make sure the ignition switch was on while trying to com-
municate with the PCM.
Turn the ignition off.
Disconnect the PCM harness connectors.
CAUTION: Do not probe the PCM harness connectors. Probing the
PCM harness connectors will damage the PCM terminals resulting
in poor terminal to pin connection. Install Miller Special Tool #8815
to perform diagnosis.
Using a 12-volt test light connected to ground probe the appropriate ter-
minal of special tool #8815.
Does the test light illuminate brightly?
Ye s>>
Go To 2
No>>
Repair the open or short to ground in the (A919) Fused B+
circuit. Inspect and replace fuses as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.(F202), (F1), (T751) PCM FUSED IGNITION SWITCH CIRCUITS
Using a 12-volt test light connected to ground, probe the PCM Fused
Ignition Switch Output circuits in the appropriate terminals of special tool
#8815.
Does the test light illuminate brightly?
Ye s>>
Go To 3
No>>
Repair the (F202) (F1) (T751) Ignition Switch Output cir-
cuits. Inspect and replace fuses as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)