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8.WASTEGATE SOLENOID
Reconnect the ECM harness connector.
Reconnect the disconnected Wastegate Solenoid harness connector.
Turn the Ignition on, engine not running.
Disconnect the Wastegate Solenoid harness connector.
Connect an incandescent test light across the supply and driver pins at
the Wastegate Solenoid harness connector.
NOTE: The ECM will perform a self check of the circuit after
approximately 30 seconds, which should light the incandescent
test light.
Does the light illuminate brightly after 30 seconds of being
connected?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diag-
nostic Procedure). (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
No>>
Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
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P0251-CP3 PUMP REGULATOR CONTROL
For a complete wiring diagramRefer to Section 8W.
Page 587 of 5267

When Monitored:
When the ignition is on.
Set Condition:
The ECM detects a discrepancy between the PWM supplied to the Electronic Fuel Control Actuator and the
PWM returned from the Electronic Fuel Control Actuator.
Possible Causes
FUEL PUMP
(K181) FUEL CONTROL ACTUATOR DRIVER OPEN
(K31) RETURN CIRCUIT OPEN FROM FCA TO ECM
(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO EXTERNAL VOLTAGE
(K31) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO EXTERNAL VOLTAGE
(K31) FCA RETURN CIRCUIT SHORTED TO (K181) FCA DRIVER CIRCUIT
(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO GROUND
(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT
(K31) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO ANOTHER CIRCUIT
INTERMITTENT CONDITION
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.FUEL PUMP
Ignition on, engine not running.
Disconnect the Fuel Control Actuator (FCA) harness connector.
Connect an incandescent test light across the Fuel Control Actuator
driver circuit and the Fuel Control Actuator return circuit at the fuel con-
trol actuator harness connector.
Observe the test light.
The ECM will perform a self test of the circuit which should momentarily
flash the test light brightly, one time, approximately 20 seconds after
being connected.
NOTE: Check connectors - Clean/repair as necessary.
NOTE: Compare test light brightness to that of a direct connection
to the battery.
Did the light flash brightly?
Ye s>>
Replace the Fuel Pump.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 2
Page 588 of 5267
2.(K181) FUEL CONTROL ACTUATOR DRIVER OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the FCA driver circuit between the electronic
fuel control actuator harness connector and the ECM harness connec-
tor.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 3
No>>
Repair the (K181) Fuel Control Actuator Driver circuit
OPEN.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
3.(K31) RETURN CIRCUIT OPEN
Measure the resistance of the (K31) return circuit between the FCA har-
ness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 4
No>>
Repair or replace the engine wiring harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
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4.(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO EXTERNAL VOLTAGE
Measure the voltage between the (K181) FCA driver circuit in the FCA
harness connector and battery negative.
Is the voltage greater than 1 volts?
Ye s>>
Repair the (K181) FCA driver circuit shorted to external volt-
age.
No>>
Go To 5
5.(K31) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO EXTERNAL VOLTAGE
Measure the voltage between the (K31) FCA return circuit in the FCA
harness connector and battery negative.
Is the voltage greater than 1 volts?
Ye s>>
Repair the (K31) FCA return circuit shorted to external volt-
age.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 6
6.(K31) FCA RETURN CIRCUIT SHORTED TO (K181) FCA DRIVER CIRCUIT
Measure the Resistance between the return circuit in the FCA harness
connector and Driver circuit.
Is the resistance less than 10 Ohms?
Ye s>>
Repair the (K31) FCA Return circuit shorted to (K181) FCA
Driver circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 7
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7.(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO GROUND
Measure the resistance between the (K181) FCA driver circuit in the
FCA harness connector and battery negative.
Is the resistance less than 10 Ohms?
Ye s>>
Repair the (K181) FCA driver circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
No>>
Go To 8
8.(K181) FUEL CONTROL ACTUATOR DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT
Measure the resistance between the (K181) FCA driver circuit in the
ECM harness connector and all other circuits in the ECM connectors.
Is the resistance less than 10 Ohms?
No>>
Go To 9
Ye s>>
Repair the (K181) FCA driver circuit shorted to another cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
9.(K31) FUEL CONTROL ACTUATOR RETURN CIRCUIT SHORTED TO ANOTHER CIRCUIT
Measure the resistance between the (K31) FCA Return circuit in the
ECM harness connector and all other circuits in the ECM connectors.
Is the resistance less than 10 Ohms?
No>>
Go To 10
Ye s>>
Repair the (K31) FCA Return circuit shorted to another cir-
cuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 591 of 5267
10.ECM
Reconnect the ECM harness connectors.
Ignition on, engine not running.
Disconnect the Electronic Fuel Control Actuator connector.
Connect an incandescent test light across the Fuel Control Actuator
driver pin and the Fuel Control Actuator return wire at the fuel control
actuator connector.
Observe the test light.
The ECM will perform a self test of the circuit which should momentarily
flash the test light brightly, one time, approximately 20 seconds after
being connected.
NOTE: Compare test light brightness to that of a direct connection
to the battery.
Did the light flash brightly?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diag-
nostic Procedure). (Refer to 9 - ENGINE - DIAGNOSIS
AND TESTING)
No>>
Replace the ECM.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
Page 592 of 5267
P0299-BOOST IN RANGE LOW
For a complete wiring diagramRefer to Section 8W.