Electronic Control Modules: Diagnosis Dodge Pickup R2500

DIAGNOSIS AND TESTING - FRONT CONTROL MODULE

The front control module is a printed circuit board based module with a on-board microprocessor. The front control module interfaces with other electronic modules in the vehicle via the Programmable Communications Interface (PCI) data bus (J1850). In order to obtain conclusive testing, the Programmable Communications Interface (PCI) data bus network and all of the electronic modules that provide inputs to or receive outputs from the front control module must be checked. All PCI (J1850) communication faults must be resolved prior to further diagnosing any front control module related issues.

The front control module was designed to be diagnosed with an appropriate diagnostic scan tool, such as the DRBIII(R). The most reliable, efficient, and accurate means to diagnose the front control module requires the use of a DRBIII(R) scan tool and BODY DIAGNOSTIC PROCEDURES .

Before any testing of the front control module is attempted, the battery should be fully charged and all wire harness and ground connections inspected around the affected areas on the vehicle.

DIAGNOSIS AND TESTING - HEATED SEAT MODULE

If a heated seat fails to heat and one or both of the indicator lamps on a heated seat switch flash, refer to HEATED SEAT SYSTEM for flashing LED heated seat system diagnosis and testing procedures. If a heated seat heats, but one or both indicator lamps on the heated seat switch fail to operate, test the heated seat switch. Refer to HEATED SEAT SWITCH for heated seat switch diagnosis and testing procedures. If the heated seat switch checks OK, proceed as follows.

1. Check the heated seat element. Refer to «HEATED SEAT ELEMENT»(ref-189816-S02147862592005091200000) . ).
2. Check the heated seat sensor. Refer to «HEATED SEAT SENSOR»(ref-189816-S00593461282005091200000) .
3. Check the heated seat switch. Refer to «HEATED SEAT SWITCH»(ref-189816-S21969396352005091200000) . NOTE: Refer to «SYSTEM WIRING DIAGRAMS - R1500»(ref-154276) , «SYSTEM WIRING DIAGRAMS - R2500»(ref-154277) or «SYSTEM WIRING DIAGRAMS - R3500»(ref-154278) for the location of complete heated seat system wiring diagrams and connector pin-out information.
4. Using a voltmeter, backprobe the appropriate heated seat module connector (DO NOT disconnect). Check for voltage at the appropriate pin cavities. 12 volts should be present. If OK, go to next step. If not, repair the open or shorted voltage supply circuit as required.
5. Using an ohmmeter, backprobe the appropriate heated seat module connector (DO NOT disconnect). Check for proper continuity to ground on the ground pin cavities. Continuity should be present. If OK, replace the heated seat module with a known good unit and retest system. If not, repair the open or shorted ground circuit as required.