2007 Liberty KJ Factory Service Manual 8 - ELECTRICAL

*STORED LOST COMMUNICATION DTCS

For a complete wiring diagram Refer to Section 8W.

When Monitored:

With the ignition on
Battery voltage between 10 and 16 volts
IOD fuse installed

Set Condition:
Bus messages not received from for approximately 500ms.

Possible Causes

CAN C BUS CIRCUITS OPEN OR SHORTED

DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES

POWER OR GROUND FROM THE REPORTING MODULE

MODULE THAT SET THIS DTC

PREVIOUS SERVICE PERFORMED WITHIN THE LAST 100 KEY CYCLES (FUSE/RELAYS REMOVED, WIRING SERVICE, BATTERY DISCONNECT)

LOW BATTERY/JUMP START CONDITION

IOD FUSE WAS REMOVED DURING SHIPPING

CHECK FOR RELATED TSBS

Diagnostic Test

1. VERIFY DTC IS STORED

NOTE: Stored faults may indicate a customer perceived intermittent condition.

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10 and 16 volts before proceeding.

Turn the ignition on.
With the scan tool, read stored DTCs.

Is this DTC stored?

Yes

Go To 2

No

Diagnose the active DTC. Refer to the table of contents for a list of the symptoms.

2. CHECK THE ENVIRONMENTAL DATA

With the scan tool, read the loss of communication environmental data.

Does the loss of communication environmental odometer data match up to any of the previous service procedures listed in the possible causes or are their any stored CAN C hardware electrical, battery, ignition voltage, VIN missing/mismatch DTCs present which match environmental data?

Yes

These DTCs may have been the result of other service procedures performed. Clear DTCs.

Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE)

No

Go To 3

3. VERIFY INTERMITTENT LOST COMMUNICATION DTC-WIRING CONCERNS

With the scan tool, select Network View and select Advanced.

Is there more than one ECU with stored DTCs “Logged Against” the module and one or more lost communication DTCs stored in the offending module?

Yes

Verify if the vehicle was recently in for this type of service. Otherwise, visually inspect the related wiring harness for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals. Repair as necessary.

No

Go To 4

4. VERIFY INTERMITTENT LOST COMMUNICATION DTC-OFFENDING MODULE

With the scan tool, select Network View and select Advanced.

Is there more than one ECU with stored DTCs “Logged Against” the module and NO lost communication DTCs stored in the offending module?

Yes

Check for a TSB related to this offending module.

No

Go To 5

5. VERIFY INTERMITTENT LOST COMMUNICATION DTC-REPORTING MODULE

With the scan tool, select Network View and select Advanced.

Is there ONLY ONE ECU with stored DTCs “Logged Against” the module?

Yes

Check for a TSB related to the module that set this DTC.

No

Verify if the vehicle was recently in for this type of service. Otherwise, visually inspect the related wiring harness for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals. Repair as necessary.