C 1500 Truck 2WD V8-6.5L DSL Turbo VIN F (1998)
5. If Inflatable Restraint Sensing and Diagnostic Module not accessible with a scan tool, check for an open in TAN (800) wire between component
and DLC terminal 9.
6. If Transfer Case Control Module is not able to flash DTC's, check for an open in ORN (1568) wire between component and DLC terminal 13.
7. If EVO/Passlock Module is not accessible with a scan tool, check for an open in PPL (1807) wire between component and Splice S280.
8. Check for proper installation of aftermarket electronic equipment that may affect the integrity of other systems.
^
CHECK for a broken or partially broken wire inside of the insulation which could cause system malfunction but prove GOOD in a
Continuity/Voltage check with a system disconnected. These Circuits may be intermittent or resistive when loaded, and if possible, should be
checked by monitoring for a Voltage drop with the system operational or under load.
^
CHECK for proper installation of aftermarket electronic equipment which may affect the integrity of other system.
9. Do not clear DTCs unless directed by a diagnostic procedure. Clearing DTCs clears valuable Freeze Frame and Failure Records data.
10. Inspect all related wiring and connections including the connections at the VCM, PCM and the ATC Module.
11. If the serial data line is shorted to ground or voltage, all systems connected to the serial data line will not communicate properly. Systems capable
of storing loss of communications DTCs (DTCs with the letter U as a prefix) will have these codes stored in memory. If a DTC U1026 is stored in
the VCM, PCM memory, check for the same DTC stored in the EBCM. The EBCM also monitors the Node Alive / SOH message from the ATC
Module. If the EBCM also has a DTC U 1026 stored, check the ATC for an intermittent malfunction. If the ATC Module does not have a DTC
U1026 stored, check for an open in the serial data line between the VCM, PCM and the ATC. Check the VCM, PCM for intermittent operation
due to a loss of power or ground. After repairing a DTC U1026, clear DTCs from all systems capable of storing this DTC. The scan tool's
Diagnostic Circuit Check can be used to: Monitor the Class 2 serial data circuit for Node Alive / SOH messages, store loss of communications
DTCs, and clear loss of communications DTCs. The scan tool Diagnostic Circuit Check status of Active indicates that the module previously
communicated with the scan tool, but currently not communicating. If a module is not listed at all, that indicates the module never successfully
established communications with the scan tool. Refer to Electrical Diagnosis for any unlisted modules.
