TEST ACTION APPLICABILITY
21 Turn the ignition off.
Replace the Fuel Quantity Solenoid in accordance with the Service Information.
Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Attempt to start and test drive the vehicle.
With the DRBIIIt, read the ECM DTCs.
Did this DTC set again?All
Ye s!Replace the Fuel Pump in accordance with the Service Informa-
tion.
Perform ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
124
DRIVEABILITY - DIESEL
P2015-FUEL RAIL PRESSURE MALFUNCTION MAXIMUM FUEL FLOW
EXCEEDED Ð
Continued
Symptom List:
P2100-FUEL PUMP RELAY CIRCUIT OPEN CIRCUIT
P2100-FUEL PUMP RELAY CIRCUIT SHORTED TO GROUND
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2100-FUEL PUMP RELAY
CIRCUIT OPEN CIRCUIT.
POSSIBLE CAUSES
INTERMITTENT CONDITION
ENGINE CONTROL RELAY OUTPUT CIRCUIT OPEN
FUEL LIFT PUMP RELAY
FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORTED TO GROUND
FUEL LIFT PUMP RELAY CONTROL CIRCUIT OPEN
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRBIIIt, erase the ECM DTCs.
Crank and attempt to start the engine several times.
With the DRBIIIt, read the active ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 6
2 Turn the ignition off.
Remove the Fuel Lift Pump Relay.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Engine Control Relay
Output circuit.
Did the test light illuminate brightly?All
Ye s!Go To 3
No!Refer to Checking the ECM Power and Grounds for the related
symptom(s).
Perform ROAD TEST VERIFICATION - VER-2.
157
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Install a substitute relay in place of the Fuel Lift Pump Relay.
Turn the ignition on.
With the DRB, actuate the Fuel Lift Pump Relay.
Does the Fuel Lift Pump Relay cycle on and off?All
Ye s!Replace the Fuel Lift Pump Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Remove the Fuel Lift Pump Relay.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the Fuel Lift Pump Relay Control
circuit.
Is the resistance above 1000 ohms?All
Ye s!Go To 5
No!Repair the Fuel Lift Pump Relay Control circuit for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Remove the Fuel Lift Pump Relay.
Disconnect the ECM harness connectors.
Measure the resistance of the Fuel Lift Pump Relay Control circuit.
Is the resistance below 10.0 ohms?All
Ye s!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Fuel Lift Pump Relay Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
6WARNING: 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 DTC When Monitored and Set Conditions. 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 ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
158
DRIVEABILITY - DIESEL
P2100-FUEL PUMP RELAY CIRCUIT OPEN CIRCUIT ÐContinued
Symptom List:
P2100-FUEL PUMP RELAY CIRCUIT SHORTED TO VOLTAGE
P2100-FUEL PUMP RELAY EXCESSIVE CURRENT
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2100-FUEL PUMP RELAY
CIRCUIT SHORTED TO VOLTAGE.
POSSIBLE CAUSES
INTERMITTENT CONDITION
FUEL LIFT PUMP RELAY
FUEL LIFT PUMP RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
ENGINE CONTROL MODULE
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
Turn the ignition on.
With the DRB, actuate the Fuel Lift Pump Relay.
Does the Fuel Lift Pump Relay cycle on and off?All
Ye s!Go To 2
No!Go To 3
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 DTC When Monitored and Set Conditions. 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 ROAD TEST VERIFICATION - VER-2.
No!Test Complete.
159
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Install a substitute relay in place of the Fuel Lift Pump Relay.
Turn the ignition on.
With the DRB, actuate the Fuel Lift Pump Relay.
Does the Fuel Lift Pump Relay cycle on and off?All
Ye s!Replace the Fuel Lift Pump Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 4
4 Turn the ignition off.
Remove the Fuel Lift Pump Relay.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector.
Turn the ignition on.
Measure the voltage of the Fuel Lift Pump Relay Control circuit.
Is the voltage below 1.0 volt?All
Ye s!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Fuel Lift Pump Relay Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
160
DRIVEABILITY - DIESEL
P2100-FUEL PUMP RELAY CIRCUIT SHORTED TO VOLTAGE ÐContinued
Symptom List:
P2151-FUEL PRESS SOLENOID SIGNAL PLAUSIBILITY HIGH
P2151-FUEL PRESS SOLENOID SIGNAL PLAUSIBILITY LOW
P2500-FUEL PRESSURE SOLENOID CIRCUIT OPEN CIRCUIT
P2501-FUEL PRESSURE SOLENOID CIRCUIT SHORTED TO
GROUND OR B+
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be P2151-FUEL PRESS SOLENOID
SIGNAL PLAUSIBILITY HIGH.
When Monitored and Set Condition:
P2500-FUEL PRESSURE SOLENOID CIRCUIT OPEN CIRCUIT
When Monitored: With the ignition on.
Set Condition: The ECM detects an open or short to ground on the Fuel Pressure Solenoid
Control circuit.
P2501-FUEL PRESSURE SOLENOID CIRCUIT SHORTED TO GROUND OR B+
When Monitored: With the ignition on and the ECM attempting to actuate the Fuel
Pressure Solenoid.
Set Condition: The ECM detects excessive current on the Fuel Pressure Solenoid Control
circuit when attempting to actuate the Fuel Pressure Solenoid.
POSSIBLE CAUSES
CHECKING THE ENGINE CONTROL RELAY SYSTEM
INTERMITTENT CONDITION
FUEL PRESSURE SOLENOID CONTROL SHORTED TO VOLTAGE
FUEL PRESSURE SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
FUEL PRESSURE SOLENOID CONTROL CIRCUIT OPEN
FUEL PRESSURE SOLENOID
ENGINE CONTROL MODULE
173
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
1NOTE: If the ECM detects and stores a DTC, the ECM also stores the
engine/vehicle operating conditions under which the DTC was set. Some of
these conditions are displayed on the DRB at the same time the DTC is
displayed.
NOTE: Before erasing stored DTCs, record these conditions. Attempting to
duplicate these conditions may assist when checking for an active DTC.
WARNING: HIGH-PRESSURE FUEL LINES DELIVER DIESEL FUEL UN-
DER EXTREME PRESSURE FROM THE INJECTION PUMP TO THE FUEL
INJECTORS. THIS MAY BE AS HIGH AS 23,200 PSI (1600 BAR). USE
EXTREME CAUTION WHEN INSPECTING FOR HIGH-PRESSURE FUEL
LEAKS.
WARNING: FUEL UNDER THIS AMOUNT OF PRESSURE CAN PENE-
TRATE SKIN CAUSING PERSONAL INJURY OR DEATH. INSPECT FOR
HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF CARDBOARD. WEAR
SAFETY GOGGLES AND ADEQUATE PROTECTIVE CLOTHING WHEN
SERVICING FUEL SYSTEM.
Turn the ignition on.
With the DRB, erase ECM DTCs.
Start the engine several times, turning the ignition off for at least 30 seconds
between each run cycle.
Monitor the DRB for ECM DTCs.
Did this DTC set again?All
Ye s!Go To 2
No!Go To 8
2NOTE: Check the ECM for other ECM DTC's related to circuits that are
open, shorted to ground or low voltage problems.
Does the DRB also display these type of DTC's?All
Ye s!Go To 3
No!Go To 4
3 Turn the ignition off.
Disconnect the ECM harness connectors.
Turn the ignition on.
Connect a jumper wire between ground and the Engine Control Relay Signal circuit
in ECM C2 harness connector cavity 44.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C1 harness connector cavities 1, 3 and 5.
Does the test light illuminate brightly for each circuit?All
Ye s!Go To 4
No!Refer to symptom list and perform Checking the ECM Power and
Grounds.
Perform ROAD TEST VERIFICATION - VER-2.
174
DRIVEABILITY - DIESEL
P2151-FUEL PRESS SOLENOID SIGNAL PLAUSIBILITY HIGH Ð
Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Fuel Pressure Solenoid harness connector.
Disconnect the ECM harness connectors.
Remove the Engine Control Relay.
Connect a jumper wire between cavity 30 and cavity 87 of the Engine Control Relay
connector.
Turn the ignition on.
Measure the voltage of the Fuel Pressure Solenoid Control circuit.
Is the voltage below 1.0 volt?All
Ye s!Go To 5
No!Repair the Fuel Pressure Solenoid Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
5 Turn the ignition off.
Disconnect the Fuel Pressure Solenoid harness connector.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the Fuel Pressure Solenoid Control
circuit.
Measure the resistance between ground and the Fuel Pressure Solenoid 12-volt
Supply
Is the resistance above 1000 ohms for both measurements?All
Ye s!Go To 6
No!Repair the Fuel Pressure Solenoid circuit(s) for a short to ground.
Perform ROAD TEST VERIFICATION - VER-2.
6 Turn the ignition off.
Disconnect the Fuel Pressure Solenoid harness connector.
Disconnect the ECM harness connectors.
Measure the resistance of the Fuel Pressure Solenoid Control circuit.
Measure the resistance of the Fuel Pressure Solenoid 12-volt Supply circuit.
Is the resistance below 10.0 ohms for both measurements?All
Ye s!Go To 7
No!Repair the Fuel Pressure Solenoid circuit(s) for an open.
Perform ROAD TEST VERIFICATION - VER-2.
175
DRIVEABILITY - DIESEL
P2151-FUEL PRESS SOLENOID SIGNAL PLAUSIBILITY HIGH Ð
Continued