Symptom:
P1594-CHARGING SYSTEM VOLTAGE TOO HIGH
When Monitored and Set Condition:
P1594-CHARGING SYSTEM VOLTAGE TOO HIGH
When Monitored: The engine running. The engine speed greater than 380 RPM.
Set Condition: Battery voltage is 1 volt greater than desired system voltage.
POSSIBLE CAUSES
TARGET VOLTAGE DIFFERS FROM BATTERY VOLTAGE
INTERMITTENT CONDITION
GENERATOR FIELD DRIVER CIRCUIT SHORTED TO GROUND
GENERATOR FIELD
POWERTRAIN CONTROL MODULE
TEST ACTION APPLICABILITY
1Note: Battery must be fully charged.
Note: Generator Belt tension and condition must be checked before con-
tinuing.
Turn the ignition on.
With DRBIIIt, actuate the Generator Field Driver.
With a 12-volt test light connected to ground, backprobe the Generator Field Driver
circuit in the back of Generator Field harness connector.
Does the test light illuminate brightly and flash?All
Ye s®Go To 2
No®Go To 5
2 With DRBIIIt, stop all actuation.
Turn the ignition on.
With DRBIIIt, read the Target Charging voltage.
Is the Target Charging voltage above 13 volts?All
Ye s®Go To 3
No®Go To 4
3 Start the engine.
With the DRBIIIt, manually set the engine speed to 1600 RPM.
With DRBIIIt, read both the Battery voltage and the Target Charging voltage.
Compare the Target Charging Voltage to the Battery Voltage reading.
Monitor voltage for 5 minutes, if necessary. Look for a 1.0 volt difference or more.
Was there more than a 1.0 volt difference?All
Ye s®Replace the Powertrain Control Module in accordance with the
Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 4
18
CHARGING
TEST ACTION APPLICABILITY
4WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Test Complete.
5 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the Generator Field Driver circuit from the PCM harness
connector to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Generator Field Driver circuit shorted to ground.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 6
6 Turn the ignition off.
Disconnect the Generator Field harness connector.
Measure resistance of the Generator Field Driver terminal to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair or replace the shorted Generator as necessary.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 7
7 If there are no possible causes remaining, view repair. All
Repair
Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
19
CHARGING
P1594-CHARGING SYSTEM VOLTAGE TOO HIGH ÐContinued
Symptom:
P1682-CHARGING SYSTEM VOLTAGE TOO LOW
When Monitored and Set Condition:
P1682-CHARGING SYSTEM VOLTAGE TOO LOW
When Monitored: With the ignition on. Engine RPM greater than 1152 RPM. With no
other charging system codes set.
Set Condition: The battery sensed voltage is 1 volt below the charging goal for 13.47
seconds. The PCM senses the battery voltage turns off the field driver and senses the
battery voltage again. If the voltages are the same, the code is set.
POSSIBLE CAUSES
BATTERY TEMPERATURE
B+ CIRCUIT HIGH RESISTANCE
GENERATOR GROUND HIGH RESISTANCE
INTERMITTENT CONDITION
GENERATOR FIELD DRIVER CIRCUIT OPEN
ASD RELAY OUTPUT CIRCUIT OPEN
GENERATOR
TEST ACTION APPLICABILITY
1NOTE: Inspect the vehicle for aftermarket accessories that may exceed the
Generator System output.
Turn the ignition off.
NOTE: The battery must be fully charged.
NOTE: The Generator belt tension and condition must be checked before
continuing.
Start the engine.
Allow the idle to stabilize.
With the DRBIIIt, read the Target Charging Voltage.
Is the Target Charging Voltage above 15.1 volts?All
Ye s®Go To 2
No®Go To 3
20
CHARGING
TEST ACTION APPLICABILITY
2WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Turn the ignition on.
NOTE: Ensure all wires are clear of the engine's moving parts.
Measure the voltage between the Generator B+ Terminal and the Battery+ Post.
Start the engine.
Is the voltage above 0.4 volt?All
Ye s®Repair the B+ circuit for high resistance between the Generator
and Battery.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 3
3WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Start the engine.
Warm the engine to operating temperature.
NOTE: Ensure all wires are clear of the engine's moving parts.
Measure the voltage between the Generator case and Battery ground post.
Is the voltage above 0.1 volt?All
Ye s®Repair Generator Ground for high resistance, Generator Case to
Battery ground side.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Go To 4
4 Start the engine.
WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
Turn on all accessories, manually set engine speed to 1600 RPM.
With DRBIIIt, read Target Charging and Charging voltage.
Compare the two readings.
Is there more than a 1.0 volt difference?All
Ye s®Go To 5
No®Go To 8
5 Turn the ignition off.
Disconnect the PCM harness connector.
Disconnect the Generator Field harness connector.
Measure the resistance of the Generator Field Driver circuit from the PCM harness
connector to Generator harness connector.
Is the resistance below 5.0 ohms?All
Ye s®Go To 6
No®Repair the Generator Field Driver circuit an open.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
21
CHARGING
P1682-CHARGING SYSTEM VOLTAGE TOO LOW ÐContinued
TEST ACTION APPLICABILITY
6 Disconnect the Generator Field harness connector.
Turn the ignition on.
With the DRBIIItactuate the Generator Field Driver.
Using a 12-volt test light connected to ground, probe the ASD Relay Output circuit.
Does the test light illuminate brightly?All
Ye s®Go To 7
No®Repair the ASD Relay Output circuit.
Perform POWERTRAIN VERIFICATION TEST VER - 3.
7 If there is no possible causes remaining, view repair. All
Ye s®Repair or replace the Generator as necessary..
Perform POWERTRAIN VERIFICATION TEST VER - 3.
8WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER - 3.
No®Test Complete.
22
CHARGING
P1682-CHARGING SYSTEM VOLTAGE TOO LOW ÐContinued
TEST ACTION APPLICABILITY
5 Turn the ignition on.
With the DRB III, display the VIN that is programmed in the PCM.
Was the correct VIN programmed into the PCM?All
Ye s®Go To 6
No®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform SKIS VERIFICATION TEST.
6 Turn the ignition off.
Replace and program the Sentry Key Immobilizer Module in accordance with the
Service Information.
Turn the ignition on.
With the DRB III, erase all SKIM and PCM DTCs.
Attempt to start and idle the engine.
With the DRB III, read the PCM DTCs.
Does the DRB III display this code?All
Ye s®Replace and program the Powertrain Control Module in accor-
dance with the Service Information.
Perform SKIS VERIFICATION TEST.
No®Test Complete.
7NOTE: This DTC could have been set if the SKIM harness connector was
disconnected, or if the SKIM was replaced recently.
NOTE: All keys that the customer uses for this vehicle must be tested to
verify they are operating properly.
Turn the ignition on.
Verify the correct VIN is programmed into the PCM and SKIM.
Turn the ignition off.
With the next customer key turn the ignition key on and crank the engine to start.
With the DRB III, read the PCM DTCs. Look for P1685
Is the Starts Since Set counter for DTC P1685 displayed and equal to 0?All
Ye s®Replace the Ignition Key.
Perform SKIS VERIFICATION TEST.
No®Test Complete.
NOTE: If this DTC cannot be reset, it could have been an actual theft
attempt.
25
COMMUNICATION
P1685-WRONG OR INVALID KEY MSG RECEIVED FROM SKIM Ð
Continued
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Replace the Sentry Key Immobilizer Module in accordance with the Service Infor-
mation.
Turn the ignition on.
Display and erase all PCM and SKIM DTCs.
Perform 5 ignition key cycles leaving the ignition key on for 90 seconds per cycle.
With the DRB, display PCM DTCs.
Does the DRB display the same DTC?All
Ye s®Replace and program the PCM in accordance with the Service
Information.
Perform SKIS VERIFICATION TEST.
No®Test Complete.
5WARNING: KEEP CLEAR OF THE ENGINE'S MOVING PARTS.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running and at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DTC When Monitored and Set Conditions. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform SKIS VERIFICATION TEST.
No®Test Complete.
27
COMMUNICATION
P1686-NO SKIM BUS MESSAGE RECEIVED ÐContinued
TEST ACTION APPLICABILITY
3WARNING: WHEN THE ENGINE IS OPERATING, DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE
PULLEYS, BELTS OR FAN. DO NOT WEAR LOOSE CLOTHING.
NOTE: The conditions that set the DTC are not present at this time. The
following list may help in identifying the intermittent condition.
With the engine running at normal operating temperature, monitor the DRB
parameters related to the DTC while wiggling the wiring harness. Look for param-
eter values to change and/or a DTC to set.
Review the DRB Freeze Frame information. If possible, try to duplicate the
conditions under which the DTC was set.
Refer to any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or
partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed
out, or corroded terminals.
Were any of the above conditions present?All
Ye s®Repair as necessary
Perform POWERTRAIN VERIFICATION TEST VER-1.
No®Test Complete.
29
COMMUNICATION
P1695-NO CCD/J1850 MESSAGE FROM BODY CONTROL MODULE Ð
Continued