Page 810 of 5267
4.OPEN SIGNAL CIRCUIT
Disconnect the ECM connectors.
Disconnect the APPS connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the APPS 1 signal circuit between the APPS
sensor connector and the ECM connector.
Ye s>>
Go To 5
No>>
Repair or Replace the harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
5.OPEN SUPPLY CIRCUIT
Measure the resistance of the APPS 1 supply circuit between the APPS
sensor connector and the ECM connector.
Is the resistance less than 10 ohms?
Ye s>>
Go To 6
No>>
Repair or replace the open harness.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 821 of 5267

When Monitored:
While the key is on and during engine operation.
Set Condition:
The APPS circuit voltage at the ECM goes below 0.13 volt for more than 2 seconds.
Possible Causes
APPS
ECM
(K23) APPS NO. 1 SIGNAL CIRCUIT OPEN
(F855) APPS NO. 1 5-VOLT SUPPLY OPEN
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS
(F855) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F855) APPS NO. 1 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.(K23) APPS NO. 1 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the APPS harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the (K23) APPS No. 1 signal circuit between
the APPS sensor harness connector and the ECMharness connector.
Is the resistance less than 10 ohms?
Ye s>>
Go To 2
No>>
Repair the (K23) APPS No. 1 signal circuit open.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 826 of 5267

When Monitored:
While the key is on and during engine operation.
Set Condition:
The APPS signal circuit voltage at the ECM goes above 4.24 volts for more than 2 seconds.
Possible Causes
(K167) APPS NO. 1 RETURN CIRCUIT OPEN
(K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO (K852) APPS NO. 1 5-VOLT SUPPLY
(K23) APPS SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT
ECM
APPS
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.(K167) APPS NO. 1 RETURN CIRCUIT OPEN
Turn the ignition off.
Disconnect the APPS harness connector.
Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance on the (K167) APPS No. 1 return circuit
between the sensor harness connector and the ECM harness connec-
tor.
Is the resistance less than 10 ohms?
Ye s>>
Go To 2
No>>
Repair the (K167) APPS No. 1 return circuit open.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 830 of 5267

When Monitored:
While the key is on and during engine operation.
Set Condition:
The APPS circuit voltage at the ECM goes below 0.13 volt for more than 2 seconds.
Possible Causes
APPS
ECM
(K29) APPS NO. 2 SIGNAL CIRCUIT OPEN
(F856) APPS NO. 2 5-VOLT SUPPLY OPEN
(K29) APPS NO. 2 SIGNAL CIRCUIT SHORTED TO GROUND
(K29) APPS NO. 2 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS
(F856) APPS NO. 2 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
(F856) APPS NO. 2 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.(K29) APPS NO. 2 SIGNAL CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the APPS harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the (K29) APPS No. 2 signal circuit between
the APPS sensor harness connector and the ECMharness connector.
Is the resistance less than 10 ohms?
Ye s>>
Go To 2
No>>
Repair the (K29) APPS No. 2 signal circuit open.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 835 of 5267

When Monitored:
While the key is on and during engine operation.
Set Condition:
The APPS signal circuit voltage at the ECM goes above 4.24 volts for more than 2 seconds.
Possible Causes
(K400) APPS NO. 1 RETURN CIRCUIT OPEN
(K29) APPS NO. 2 SIGNAL CIRCUIT SHORTED TO (K854) APPS NO. 2 5-VOLT SUPPLY
(K29) APPS SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT
ECM
APPS
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.(K400) APPS NO. 2 RETURN CIRCUIT OPEN
Turn the ignition off.
Disconnect the APPS harness connector.
Disconnect the ECM harness connectors.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance on the (K400) APPS No. 2 return circuit
between the sensor harness connector and the ECM harness connec-
tor.
Is the resistance less than 10 ohms?
Ye s>>
Go To 2
No>>
Repair the (K400) APPS No. 2 return circuit open.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 839 of 5267

When Monitored:
While the engine is running.
Set Condition:
A circuit failure detected at cylinders 1,2, or 3 or any combination of cylinders 1,2, or 3.
Possible Causes
OTHER DTC’S
HIGH SIDE DRIVER CIRCUIT OPEN
LOW SIDE DRIVER CIRCUIT OPEN
HIGH SIDE DRIVER SHORTED TO LOW SIDE DRIVER
HIGH SIDE DRIVERS SHORTED LOW
LOW SIDE DRIVER CIRCUIT SHORTED OTHER LOW SIDE DRIVER CIRCUIT
LOW SIDE DRIVERS SHORTED LOW
HIGH SIDE DRIVER SHORTED TO VOLTAGE
LOW SIDE DRIVER SHORTED TO VOLTAGE
LOW SIDE DRIVER CIRCUIT SHORTED IN INJECTOR HARNESS
INJECTOR
INJECTOR HARNESS
INTERMITTENT CONDITION
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
With the scan tool, read DTCs.
Do you have any combination of DTC’s P0201, P0202, or P0203?
Ye s>>
Repair other DTC’s first.
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 SIDE DRIVER CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Injector 1-3 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the injector high side driver circuit between
the Bank 1 high side driver circuit in the ECM harness connector and
the high side driver circuit in the injector harness connectors for cylin-
ders 1-3.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 3
No>>
Repair the open high side driver circuit from ECM harness
connector to the Injector harness connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
Page 844 of 5267
11 .INJECTOR CIRCUITS SHORTED INSIDE ENGINE
Disconnect the injector through head harness connector.
Measure the resistance of each injector from the through head connec-
tor.
NOTE: Be sure to zero the ohm meter prior to checking the injec-
tor circuit.
Is the resistance greater than 0 ohms and less than 1 ohm?
Ye s>>
Go To 12
No>>
Go To 14
12.INJECTOR
Disconnect the pigtail nuts from injectors 1-3.
NOTE: Check connectors - Clean/repair as neces-
sary.
Measure the resistance between the solenoid posts of
each injector.
NOTE: Be sure to zero the ohm meter prior to
checking the injector circuit.
Is the resistance less than 1 ohm and greater
than 0 ohms?
Ye s>>
Go To 13
No>>
Replace the fuel injector or injectors.
Perform POWERTRAIN VERIFICATION
TEST VER - 1 (DIESEL). (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL
MODULES/ENGINE CONTROL MODULE -
DIAGNOSIS AND TESTING)
Page 847 of 5267

When Monitored:
While the engine is running.
Set Condition:
A misfire detected at cylinders 4,5, or 6 or any combination of cylinders 4,5, or 6.
Possible Causes
OTHER DTC’S
HIGH SIDE DRIVER CIRCUIT OPEN
LOW SIDE DRIVER CIRCUIT OPEN
HIGH SIDE DRIVER SHORTED TO LOW SIDE DRIVER
HIGH SIDE DRIVERS SHORTED LOW
LOW SIDE DRIVER CIRCUIT SHORTED OTHER LOW SIDE DRIVER CIRCUIT
LOW SIDE DRIVERS SHORTED LOW
HIGH SIDE DRIVER SHORTED TO VOLTAGE
LOW SIDE DRIVER SHORTED TO VOLTAGE
LOW SIDE DRIVER CIRCUIT SHORTED IN INJECTOR HARNESS
INJECTOR
INJECTOR HARNESS
ECM
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.OTHER DTC’S
With the scan tool, read DTCs.
Do you have any combination of DTC’s P0204, P0205, or P0206?
Ye s>>
Repair other DTC’s first.
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 SIDE DRIVER CIRCUIT OPEN
Turn the ignition off.
Disconnect the ECM harness connectors.
Disconnect the Injector 4-6 harness connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the injector high side driver circuit between
the Bank 2 high side driver circuit in the ECM harness connector and
the high side driver circuit in the injector harness connectors for cylin-
ders 4-6.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 3
No>>
Repair the open high side driver circuit from ECM harness
connector to the Injector harness connector.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-