Page 1420 of 5267

When Monitored:
With the ignition key on.
Set Condition:
The PCM senses the voltage from the Battery Temperature Sensor above 4.9 volts for 3 seconds.
Possible Causes
BATTERY TEMP SENSOR VOLTAGE ABOVE 4.8 VOLTS
BATTERY TEMPERATURE SENSOR
(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
(K25) BATTERY TEMP SIGNAL CIRCUIT OPEN
(K900) SENSOR GROUND CIRCUIT OPEN
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.BATTERY TEMP SENSOR VOLTAGE ABOVE 4.8 VOLTS
Ignition on, engine not running.
Record all DTCs and the related Freeze Frame data.
With the scan tool, monitor the Battery Temperature Sensor voltage.
Is the voltage above 4.8 volts?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.BATTERY TEMPERATURE SENSOR
Turn the ignition off.
Disconnect the Battery Temp Sensor harness connector.
Ignition on, engine not running.
With the scan tool in sensors, read the Batt Temp Sensor voltage value.
Connect a jumper wire between the (K25) Batt Temp Signal circuit and
the (K900) Sensor ground circuit at the Battery Temp Sensor connector.
NOTE: Remove the jumper wire before continuing.
Did the Battery Temp Sensor voltage change from greater than
4.5 volts to less than 1.0 volt?
Ye s>>
Replace the Battery Temperature Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
Page 1421 of 5267
3.(K25) BATT TEMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
Turn the ignition off.
Disconnect the PCM harness connectors.
Ignition on, engine not running.
Measure the voltage on the (K25) Battery Temp Signal circuit at the
Sensor harness connector.
Is the voltage above 5.2 volts?
Ye s>>
Repair the short to voltage in the (K25) Batt Temp Signal
circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
4.(K25) BATT TEMP SIGNAL CIRCUIT OPEN
Turn the ignition off.
Measure the resistance of the (K25) Battery Temp Signal circuit from
the Battery Temp Sensor harness connector to the PCM harness con-
nector.
Is the resistance below 5.0 ohms?
Ye s>>
Go To 5
No>>
Repair the open in the (K25) Batt Temp Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
Page 1423 of 5267
P1493-AMBIENT/BATTERY TEMPERATURE SENSOR VOLTAGE TOO LOW
For a complete wiring diagramRefer to Section 8W.
Page 1424 of 5267

When Monitored:
With the ignition on.
Set Condition:
The PCM senses the voltage from the Battery Temperature Sensor below 0.5 ofa volt for 3 seconds.
Possible Causes
BATTERY TEMP SENSOR VOLTAGE BELOW 0.5 OF A VOLT
BATTERY TEMPERATURE SENSOR
(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO GROUND
(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
1.BATTERY TEMP SENSOR VOLTAGE BELOW 0.5 OF A VOLT
Ignition on, engine not running.
Record all DTCs and the related Freeze Frame data.
With scan tool, monitor the Ambient/Battery Temperature Sensor voltage.
Is the voltage below 0.5 of a volt?
Ye s>>
Go To 2
No>>
Refer to the INTERMITTENT CONDITIONSymptom (Diagnostic Procedure).
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
2.BATTERY TEMPERATURE SENSOR
Ignition on, engine not running.
With the scan tool in sensors, read the Battery Temp Sensor voltage.
Disconnect the Battery Temp Sensor harness connector.
Did the Battery Temperature Sensor voltage change from below 1.0 volt to above 4.5 volts?
Ye s>>
Replace the Battery Temperature Sensor.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3
3.(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the PCM harness connectors.
Measure the resistance between ground and the (K25) Battery Temp
Signal circuit at the Battery Temp Sensor harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K25) Batt Temp Signal
circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 4
Page 1425 of 5267
4.(K25) BATTERY TEMP SIGNAL CIRCUIT SHORTED TO THE (K900) SENSOR GROUND
Measure the resistance between the (K25) Battery Temp Signal circuit
and the (K900) Sensor ground circuit at the Battery Temp Sensor har-
ness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short between the (K900) Sensor ground circuit
and the (K25) Batt Temp Signal circuit.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 -
ENGINE - STANDARD PROCEDURE)
No>>
Go To 5
5.PCM
NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and
Ground circuits.
If there are no possible causes remaining, view repair.
Repair
Replace and program the Powertrain Control Module per Service Information.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1427 of 5267

When Monitored:
Immediately after a cold start, with battery/ambient temperature between 40 Deg. F and 90 Deg. F and coolant
temperature within 10 Deg. F of battery/ambient.
Set Condition:
The state of the switch does not change when the solenoid is energized.
Possible Causes
GOOD TRIP EQUAL TO ZERO
LDP VACUUM SUPPLY
LEAK DETECTION PUMP
(K107) LDP SWITCH SENSE CIRCUIT OPEN
(K107) LDP SWITCH SENSE CIRCUIT SHORTED TO GROUND
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
Ignition on, engine not running.
With a scan tool, read DTCs and record the related Freeze Frame data if any DTC(s) are present.
Whether or not any DTC(s) are present you will want to check the following items which may assist in repairing the
customer’s complaint successfully.
Check the vehicles repair history.
If the vehicle has a repair history that pertains to the customer’s currentcomplaint, review the repair.
Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
Check for any service bulletin(s) related to the customer’s complaint or DTC(s).
If a service bulletin applies, follow the instructions per the service bulletin.
Choose the following scenario that best applies.
The service bulletin repaired the customer’s complaint.
Testing complete.
A DTC is present, no service bulletins apply, or the service bulletin didn’t repair the customer’s complaint.
Go To 2
2.GOOD TRIP EQUAL TO ZERO
Check for any related TSBs.
Ignition on, engine not running.
With the scan tool, read DTCs and record the related Freeze Frame data.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 3
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1431 of 5267

When Monitored:
Continuously when the ignition is on and battery voltage is greater than 10.4 volts.
Set Condition:
The state of the solenoid circuit does not match the PCM’s desired state.
Possible Causes
(K125) GENERATOR SOURCE CIRCUIT OPEN
(K107) LDP SWITCH SIGNAL CIRCUIT OPEN
(K107) LDP SWITCH SIGNAL CIRCUIT SHORTED TO GROUND
(K106) LEAK DETECTION PUMP SOLENOID CONTROL CIRCUIT OPEN
(K106) LDP SOLENOID CONTROL CIRCUIT SHORTED TO GROUND
LEAK DETECTION PUMP
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.VEHICLE HISTORY AND SERVICE BULLETIN INVESTIGATION
Ignition on, engine not running.
With a scan tool, read DTCs and record the related Freeze Frame data if any DTC(s) are present.
Whether or not any DTC(s) are present you will want to check the following items which may assist in repairing the
customer’s complaint successfully.
Check the vehicles repair history.
If the vehicle has a repair history that pertains to the customer’s currentcomplaint, review the repair.
Inspect the vehicle for any aftermarket accessories that may have been installed incorrectly.
Check for any service bulletin(s) related to the customer’s complaint or DTC(s).
If a service bulletin applies, follow the instructions per the service bulletin.
Choose the following scenario that best applies.
The service bulletin repaired the customer’s complaint.
Testing complete.
A DTC is present, no service bulletins apply, or the service bulletin didn’t repair the customer’s complaint.
Go To 2
2.GOOD TRIP EQUAL TO ZERO
Ignition on, engine not running.
With the scan tool, read DTCs.
Is the Good Trip Counter displayed and equal to zero?
Ye s>>
Go To 3
No>>
Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)
Page 1440 of 5267

When Monitored:
With the ignition key on and the engine speed greater than 0 RPM.
Set Condition:
When the PCM regulates the generator field and there are no detected field problems, but the voltage output
does not decrease.
Possible Causes
(K20) GENERATOR FIELD CONTROL CIRCUIT SHORTED TO GROUND
GENERATOR FIELD COIL SHORTED TO GROUND
BATTERY TEMPERATURE SENSOR
PCM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE -
DIAGNOSIS AND TESTING)
Diagnostic Test
1.CHARGING SYSTEM OPERATION
NOTE: Battery must be fully charged and be capable of passing a load test.
NOTE: Generator Belt tension and condition must be checked before continuing.
Ignition on, engine not running.
With the scan tool, read DTCs and the related Freeze Frame data then clear theDTCs.
With scan tool, actuate the Generator Field Driver.
With a 12-volt test light connected to ground, backprobe the (K20) Gen Field Control circuit in the back of Generator
Field harness connector.
Does the test light illuminate brightly and flash?
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.(K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the C2 PCM harness connector.
Disconnect the Generator Field Harness connector.
Carefully inspect the related connectors for corrosion or spread termi-
nals before continuing.
Measure the resistance between ground and the (K20) Generator Field
Driver circuit at the Generator Field harness connector.
Istheresistancebelow100ohms?
Ye s>>
Repair the short to ground in the (K20) Generator Field
Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to
9 - ENGINE - STANDARD PROCEDURE)
No>>
Go To 3