Page 682 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
BATTERY TEMP SENSOR
(K25) SIGNAL CIRCUIT SHORTED TO GROUND
(K25) SIGNAL CIRCUIT SHORTED
INTERMITTENT CONDITION
ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.BATTERY TEMP SENSOR
Turn the ignition off.
Disconnect the Battery temp sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance of the Battery temp sensor.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 2
No>>
Replace the battery temp sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
Page 683 of 5267
2.(K25) SIGNAL CIRCUIT SHORTED TO GROUND
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the resistance between the engine ground and the tempera-
ture sensor (K25) signal circuit at the sensor connector.
Istheresistancemorethan100kohms?
Ye s>>
Go To 3
No>>
Repair the Battery temp sensor (K25)signal 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)
3.(K25) SIGNAL CIRCUIT SHORTED
Measure the resistance between the Battery temp sensor (K25) signal
circuit and all other circuits in the ECM harness connector of the engine
harness.
Istheresistancemorethan100kohms?
Ye s>>
Go To 4
No>>
Repair the (K25) signal circuit shorted to another circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 684 of 5267
4.INTERMITTENT CONDITION
Reconnect the disconnected Battery temp sensor harness connector.
While monitoring with scan tool, disconnect the temperature sensor harness connector.
Did P0517 set?
Ye s>>
Refer to the INTERMITTENT CONDITION Symptom (Diagnostic 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 685 of 5267
P0517-HIGH VOLTAGE AT THE BAT TEMP SENSOR
For a complete wiring diagramRefer to Section 8W.
Page 686 of 5267

When Monitored:
With 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
BATTERY TEMP SENSOR
(K25) SIGNAL CIRCUIT OPEN
(K900) RETURN CIRCUIT OPEN
(K25) SIGNAL CIRCUIT SHORTED
ECM
INTERMITTENT CONDITION
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.BATTERY TEMP SENSOR
Disconnect the Battery temp sensor harness connector.
Check connectors - Clean/repair as necessary.
Measure the resistance of the Battery temp sensor
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 2
No>>
Replace the Battery temp sensor.
Perform POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/ENGINE CONTROL MODULE - DIAGNOSIS AND TESTING)
2.OPEN CIRCUIT
Reconnect the disconnected Battery temp sensor harness connector.
Disconnect the ECM harness connectors.
Check connectors - Clean/repair as necessary.
Measure the resistance between the temperature sensor (K25) signal
and (K900) return circuits at the ECM harness connector.
Is the resistance between 300 and 90k ohms?
Ye s>>
Go To 5
No>>
Go To 3
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3.(K25) SIGNAL CIRCUIT OPEN
Disconnect the Battery temp sensor harness connector.
Measure the resistance of the sensor (K25) signal circuit between the
sensor harness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 4
No>>
Repair the open (K25) signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
4.(K900) RETURN CIRCUIT OPEN
Measure the resistance of the sensor (K900) return circuit between the
sensor harness connector and the ECM harness connector.
Is the resistance less than 10 Ohms?
Ye s>>
Go To 5
No>>
Repair the open (K900) return circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 688 of 5267
5.(K25) SIGNAL CIRCUIT SHORTED
Check for a short circuit from (K25) signal circuit to all other circuits at
the ECM harness connector.
Istheresistancemorethan100kohms?
Ye s>>
Go To 6
No>>
Repair the shorted (K25) signal circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 1
(DIESEL). (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
6.ECM
Reconnect the ECM harness connectors.
While monitoring with the scan tool, use a jumper wire and connect the
sensor (K25) signal circuit to the sensor (K900) return circuit at the sen-
sor harness connector.
Did P0516 set?
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/ELECTRONIC CON-
TROL MODULES/ENGINE CONTROL MODULE - DIAG-
NOSIS AND TESTING)
Page 695 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
A/C PRESSURE SENSOR
(C918) SIGNAL CIRCUIT SHORTED TO (K55) RETURN CIRCUIT
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO (K55) RETURN CIRCUIT
(C918) SIGNAL CIRCUIT OPEN FROM ECM HARNESS CONNECTOR TO A/C HARNESS CONNECTOR
(F855) 5-VOLT SUPPLY CIRCUIT OPEN FROM ECM HARNESS TO A/C HARNESS CONNECTORS
(C918) SIGNAL CIRCUIT SHORTED TO GROUND
(F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
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
Turn the ignition on.
With the scan tool, read DTCs.
Are other DTC’s present?
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.HARNESS OPEN
Disconnect the A/C pressure sending unit harness connector.
Check connectors - Clean/repair as necessary.
Measure the voltage between the (F855) 5-volt supply and (K916)
return circuits of the sensor harness connector.
Is the voltage between 4.5 and 5.5 volts?
Ye s>>
Go To 3
No>>
Go To 4