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)
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)
When Monitored:
Continuous - key on or key off.
Set Condition:
Loss of voltage detected at the ECM for a calibrated amount of time.
Possible Causes
POOR CONNECTIONS AT THE BATTERIES
LOW BATTERY VOLTAGE
OPEN FUSED B+ TO ECM
OPEN GROUND CIRCUIT
BATTERY + SHORTED TO OTHER CIRCUITS
RETURN CIRCUIT SHORTED
BATTERY + SHORTED TO GROUND
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.POOR CONNECTIONS AT THE BATTERIES
Visually inspect the wiring at the battery for damaged wires, or corrosion.
Are the connections tight and free of corrosion?
Ye s>>
Go To 2
No>>
Repair the poor connections at the batteries.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.L O W B AT T E RY V O LTA G E
Measure the voltage between the positive and negative posts of the batteries.
Is the battery voltages both above 12 volts?
Ye s>>
Go To 3
No>>
Recharge or replace the battery (s).
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
U1421-IMPLAUSIBLE IGNITION KEY OFF TIME RECEIVED
For a complete wiring diagramRefer to Section 8W.
When Monitored:
Ignition on.
Set Condition:
The fuel volume message the ECM is receiving is implausible. The circuit iscontinuously monitored. One Trip
fault.
Possible Causes
CAN B OPEN OR SHORTED
CLUSTER MODULE
FCM (TOTALLY INTEGRATED POWER MODULE)
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Theory of Operation
The Totally Integrated Power Module (TIPM) isn’t receiving a fuel volume signal over CAN B from the Cluster Mod-
ule. The TIPM has to send the PCM a fuel volume signal over CAN C. The signal the TIPM sends over CAN C is
implausible.
Diagnostic Test
1.ACTIVE DTC
Ignition on, engine not running.
With a scan tool read DTCs.
Is the DTC active at this time?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.CAN B BUS HARDWARE DTCS ALSO ACTIVE
With a scan tool check for DTCs in the TIPM.
Are any CAN B Hardware related DTCs active at this time?
Ye s>>
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING) for the
appropriate diagnostic procedures.
Perform BODY VERIFICATION TEST – VER 1.
No>>
Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
P0355-IGNITION COIL #5 PRIMARY
CIRCUIT................................. 1948
P0420-1/1 CATALYTIC CONVERTER
EFFICIENCY............................. 1952
P0432-2/1 CATALYTIC CONVERTER
EFFICIENCY............................. 1955
P0441-EVAP PURGE FLOW MONITOR . . . . . 1958
P0442-EVAP LEAK MONITOR MEDIUM
(0.040) LEAK DETECTED.................. 1962
P0443-EVAP PURGE SOLENOID CIRCUIT . . 1968
P0455-EVAP LEAK MONITOR LARGE LEAK
DETECTED............................... 1972
P0460-FUEL LEVEL SENDING UNIT NO
CHANGE OVER MILES.................... 1978
P0462-FUEL LEVEL SENDING UNIT VOLTS
TOO LOW................................ 1979
P0463-FUEL LEVEL SENSOR 1 CIRCUIT
HIGH.................................... 1982
P0500-NO VEHICLE SPEED SIGNAL ....... 1986
P0505-IDLE AIR CONTROL MOTOR
CIRCUITS................................ 1989
P0513-INVALID SKREEM KEY ............. 1994
P0522-OIL PRESSURE CIRCUIT LOW ...... 1996
P0523-OIL PRESSURE CIRCUIT HIGH ..... 2000
P0601-PCM INTERNAL CONTROLLER
FAILURE................................. 2003
P0622-GENERATOR FIELD NOT
SWITCHING PROPERLY.................. 2004
P0645-A/C CLUTCH RELAY CIRCUIT . . ..... 2008
P0801-REVERSE GEAR LOCKOUT CIRCUIT
OPEN OR SHORTED...................... 2012
P1195-O2 SENSOR 1/1 SLOW DURING
CATALYST MONITOR..................... 2016
P1196-O2 SENSOR 2/1 SLOW DURING
CATALYST MONITOR..................... 2019
P126B-ASD CONTROL CIRCUIT 2 LOW .... 2022
P126C-ASD CONTROL CIRCUIT 2 HIGH .... 2026
P126D-ASD CONTROL CIRCUIT 2 OPEN . . . 2030
P126E-ASD CONTROL CIRCUIT
OVERCURRENT.......................... 2034
P1272-A/C CLUTCH CONTROL CIRCUIT 2
LOW..................................... 2038
P1273-A/C CLUTCH CONTROL CIRCUIT 2
HIGH.................................... 2041
P1274-A/C CLUTCH CONTROL CIRCUIT 2
OPEN.................................... 2045
P1275-A/C CLUTCH CONTROL CIRCUIT 2
OVERCURRENT.......................... 2049
P1277-STARTER CONTROL CIRCUIT 2 LOW
(TIPM)................................... 2052
P1278-STARTER CONTROL CIRCUIT 2
HIGH (TIPM).............................. 2055
P1279-STARTER CONTROL CIRCUIT 2
OPEN (TIPM)............................. 2058
P127A-STARTER CONTROL CIRCUIT 2
OVERCURRENT.......................... 2061
P127C-FUEL PUMP CONTROL CIRCUIT 2
LOW..................................... 2064P127D-FUEL PUMP CONTROL CIRCUIT 2
HIGH.................................... 2067
P127E-FUEL PUMP CONTROL CIRCUIT 2
OPEN (TIPM)............................. 2071
P0127F-FUEL PUMP CONTROL CIRCUIT 2
OVERCURRENT (TIPM)................... 2075
P1281-ENGINE IS COLD TOO LONG ....... 2078
P1282-FUEL PUMP/SYSTEM RELAY
CONTROL CIRCUIT....................... 2079
P1294-TARGET IDLE NOT REACHED ...... 2082
P1296-NO 5-VOLTS TO MAP SENSOR ..... 2085
P1297-NO CHANGE IN MAP FROM START
TO RUN.................................. 2089
P1388-AUTO SHUTDOWN RELAY CONTROL
CIRCUIT................................. 2094
P1389-NO ASD RELAY OUTPUT VOLTAGE
AT P C M.................................. 2097
P1391-INTERMITTENT LOSS OF CMP OR
CKP
..................................... 2100
P1398-MIS-FIRE ADAPTIVE NUMERATOR
AT L I M I T................................. 2104
P1486-EVAP LEAK MONITOR PINCHED
HOSE FOUND............................ 2106
P1492-AMBIENT/BATTERY TEMPERATURE
SENSOR VOLTAGE TOO HIGH............. 2110
P1493-AMBIENT/BATTERY TEMPERATURE
SENSOR VOLTAGE TOO LOW............. 2114
P1494-LEAK DETECTION PUMP SWITCH
OR MECHANICAL FAULT.................. 2117
P1495-LEAK DETECTION PUMP SOLENOID
CIRCUIT................................. 2121
P1499-HYDRAULIC FAN SOLENOID
CIRCUIT................................. 2126
P1594-CHARGING SYSTEM VOLTAGE TOO
HIGH.................................... 2130
P1598-A/C PRESSURE SENSOR VOLTAGE
TOO HIGH............................... 2133
P1599-A/C PRESSURE SENSOR VOLTAGE
TOO LOW................................ 2137
P1682-CHARGING SYSTEM VOLTAGE TOO
LOW..................................... 2141
P1687-NO CLUSTER BUS MESSAGE ...... 2146
P1695-BUS MESSAGE FROM BODY
CONTROL MODULE...................... 2148
P1696-PCM FAILURE EEPROM WRITE
DENIED.................................. 2151
*BRAKE SWITCH SENSE STATUS DOES
NOT CHANGE ON THE SCAN TOOL....... 2153
*CANNOT SHIFT INTO REVERSE .......... 2157
*CHECKING A/C SYSTEM OPERATION
WITH NO DTCS.......................... 2159
*CHECKING CHARGING SYSTEM
OPERATION WITH NO DTCS.............. 2163
*CHECKING RADIATOR FAN OPERATION . . 2167
*CHECKING THE PCM POWER AND
GROUNDS............................... 2169
B2277–CAN GATEWAY INTERNAL
(GATEWAY).............................. 2172
U0001–CAN C BUS CIRCUIT (GATEWAY) . . . 2172
When Monitored:
At a cold start, engine coolant below 98°F, Ambient/Battery Sensor readingwithin27°F,andEngineCoolant
Temperature above 170°F on the previous key off.
Set Condition:
The Oxygen Sensor signal voltage is below 0.156 of a volt for 28 seconds after starting engine.
Possible Causes
(K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO GROUND
(K41) O2 1/1 SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR BELOW 0.16 OF A VOLT
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Start the engine.
Allow the engine to idle for 4 to 5 minutes.
With the scan tool, read the O2 Sensor voltage.
Is the voltage below 0.16 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.O2 SENSOR OPERATION
WARNING: When the engine is operating, do not stand in a direct line with thefan. Do not put your hands
near the pulleys, belts, or fan. Do no wear loose clothing.
Disconnect the O2 Sensor harness connector.
Start the engine.
With the scan tool, monitor the O2 Sensor voltage.
IstheO2Sensorvoltageabove0.16ofavolt?
Ye s>>
Replace the O2 Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
At a cold start, engine coolant below 98°F, Ambient/Battery Sensor readingwithin27°F,andEngineCoolant
Temperature above 170°F on the previous key off.
Set Condition:
The Oxygen Sensor signal voltage is below 0.156 of a volt for 28 seconds after starting engine.
Possible Causes
(K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO GROUND
(K141) O2 SENSOR 1/2 SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
(K141) O2 SENSOR 2/1 SIGNAL SHORTED TO THE (Z1) HEATER GROUND CIRCUIT
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR BELOW 0.16 OF A VOLT
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Start the engine.
Allow the engine to idle for 4 to 5 minutes.
With the scan tool, read the O2 Sensor voltage.
Is the voltage below 0.16 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.O2 SENSOR OPERATION
WARNING: When the engine is operating, do not stand in a direct line with thefan. Do not put your hands
near the pulleys, belts, or fan. Do not wear loose clothing.
Disconnect the O2 Sensor harness connector.
Start the engine.
With the scan tool, monitor the O2 Sensor voltage.
IstheO2Sensorvoltageabove0.16ofavolt?
Ye s>>
Replace the O2 Sensor
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
When Monitored:
At a cold start, engine coolant below 98°F, Ambient/Battery Sensor readingwithin27°F,andEngineCoolant
Temperature above 170°F on the previous key off.
Set Condition:
The Oxygen Sensor signal voltage is below 0.156 of a volt for 28 seconds after starting engine.
Possible Causes
(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO GROUND
(K43) O2 2/1 SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND CIRCUIT
O2 SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING).
Diagnostic Test
1.O2 SENSOR BELOW 0.16 OF A VOLT
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Start the engine.
Allow the engine to idle for 4 to 5 minutes.
With the scan tool, read the O2 Sensor voltage.
Is the voltage below 0.16 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.O2 SENSOR OPERATION
WARNING: When the engine is operating, do not stand in a direct line with thefan. Do not put your hands
near the pulleys, belts, or fan. Do no wear loose clothing.
Disconnect the O2 Sensor harness connector.
Start the engine.
With the scan tool, monitor the O2 Sensor voltage.
IstheO2Sensorvoltageabove0.16ofavolt?
Ye s>>
Replace the O2 Sensor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3