Page 571 of 5267

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.
Possible Causes
OTHER DTC’S
(K37) SIGNAL CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT
MAP SENSOR
(K37) SIGNAL CIRCUIT OPEN
(F855) 5-VOLT SUPPLY CIRCUIT OPEN
MAP SENSOR (K37) SIGNAL CIRCUIT SHORT TO GROUND
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
Turn the ignition on.
With the scan tool, read the Engine DTC’s.
Is there a 5-volt Supply DTC set?
Ye s>>
Refer to symptom list for problems related to the 5-volt Supply DTC.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.HIGH VOLTAGE
Turn the ignition off.
Disconnect the Map sensor harness connector.
Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage between the (F855) 5-volt supply circuit and sen-
sor (K916) return circuit of the Map sensor harness connector.
Is the voltage between 4.5 and 5.5 volts?
Ye s>>
Go To 3
No>>
Go To 4
Page 572 of 5267

3.MAP SENSOR
While monitoring the scan tool, jumperthe (F855) 5-volt supply circuit to
the (K37) signal circuit in the Map sensor harness connector.
Did the P0238-MAP SENSOR VOLTAGE TOO HIGH, DTC set?
Ye s>>
Replace the MAP sensor.
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 4
4.(K37) SIGNAL CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT
Turn the ignition off.
Disconnect the ECM harness 60 pin connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance between the (K37) signal circuit and (K916)
sensor return circuit in the MAP sensor harness connector.
Is the resistance greater than 100 K Ohms?
No>>
Repair (K37) signal circuit shorted to (K916) sensor return
circuit or replace harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Ye s>>
Go To 5
5.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K916) SENSOR RETURN CIRCUIT
Measure the resistance between the (F855) 5-volt supply circuit and
(K916) sensor return circuit in the MAP sensor harness connector.
Is the resistance greater than 100 K Ohms?
No>>
Repair (F855) 5-volt supply circuit shorted to (K916)) sensor
return circuit or replace harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Ye s>>
Go To 6
Page 576 of 5267

When Monitored:
With the ignition on and battery voltage greater than 10.4 volts.
Set Condition:
The circuit voltage to the ECM is above a calibrated threshold for a certainperiod of time.
Possible Causes
OTHER DTC’S
(K37) SIGNAL CIRCUIT SHORTED TO BATTERY
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY
MAP SENSOR
(K37) SIGNAL CIRCUIT SHORT TO SUPPLY
(F855) 5-VOLT SUPPLY CIRCUIT SHORT TO BATTERY
INTERMITTENT
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
Turn the ignition on.
With the scan tool, read the Engine DTC’s.
Is there a 5-volt Supply DTC set?
Ye s>>
Refer to symptom list for problems related to the 5-volt Supply DTC.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
No>>
Go To 2
2.HIGH VOLTAGE
Turn the ignition off.
Disconnect the Map sensor harness connector.
Check connectors - Clean/repair as necessary.
Turn the ignition on.
Measure the voltage between the (F855) 5-volt supply circuit and
(K916) sensor return circuit of the Map sensor harness connector.
Is the voltage between 4.5 and 5.5 volts?
Ye s>>
Go To 3
No>>
Go To 4
Page 577 of 5267

3.MAP SENSOR
While monitoring scan tool, use a jumper wire to connect the (K916)
return circuit with the (K37) signal circuit at the sensor connector.
Did the P0237-MAP SENSOR VOLTAGE TOO LOW, DTC set?
Ye s>>
Go To 4
No>>
Replace the MAP sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
4.(K37) SIGNAL CIRCUIT SHORTED TO BATTERY
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the voltage between the (K37) signal circuit at the MAP sensor
harness connector and Battery Negative.
Is the voltage greater than 1 volt?
Ye s>>
Repair (K37) signal circuit shorted to Battery or replace har-
ness.
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 5
5.(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO BATTERY
Measure the voltage between the (F855) 5-volt supply circuit at the
MAP sensor harness connector and Battery negative.
Is the voltage greater than 1 volt?
Ye s>>
Repair (F855) 5-volt supply circuit shorted to Battery or
replace harness.
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
Page 581 of 5267

When Monitored:
When the ignition is on.
Set Condition:
The ECM detects an open or short circuit in the Wastegate solenoid circuit.
Possible Causes
DAMAGED WIRING HARNESS OR CONNECTORS
WASTEGATE SOLENOID
(F504) FUSED IGNITION SWITCH OUTPUT OPEN
(K139) WASTEGATE SOLENOID DRIVER CIRCUIT OPEN
(K139) WASTEGATE SOLENOID CIRCUIT SHORTED TO GROUND
(K139) WASTEGATE SOLENOID DRIVER SHORTED TO VOLTAGE
(K139) WASTEGATE SOLENOID DRIVER CIRCUIT SHORTED TO ANOTHER CIRCUIT
ECM
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.DAMAGED WIRING HARNESS OR CONNECTORS
Turn Ignition off.
Disconnect the ECM harness connectors.
Disconnect the Wastegate Solenoid harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Areanywiresorpinsdamaged?
Ye s>>
Repair or replace any damaged wire or connectors.
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 582 of 5267

2.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>>
Replace the Wastegate Solenoid.
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 3
3.(F504) FUSED IGNITION SWITCH OUTPUT OPEN
Connect an test light between the Wastegate Solenoid connector Fused
ignition switch output circuit and battery negative.
Compare the test light brightness to that of a direct connection to the
battery.
Does the light illuminate brightly?
Ye s>>
Go To 4
No>>
Repair the open (F504) Fused Ignition switch output circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 585 of 5267
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)
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