Pinpoint Test AC: DTC B103C: Notes

Refer to Climate Controlled Seats for schematic and connector information.

Normal Operation 

Each climate controlled seat is controlled independently of the other by the DCSM mounted to the bottom of the passenger seat cushion. The climate controlled seats only operate with the engine running, however, if using a scan tool, diagnostic testing can be carried out with the ignition ON engine OFF. The system receives voltage from BJB fuse 67 (40A) supplying battery voltage on circuit SBB67 (BU/RD) into DCSM C3265A pins E and F. If voltage is disconnected from either circuit, both seats will remain operational because voltage supply is internally connected in the DCSM. However, if a fault occurs setting a DTC specific to either climate controlled seat, only the affected seat will be disabled.

Each seat cushion and backrest is equipped with a TED that includes a seat blower that is serviced as an assembly with the TED. Cabin air is drawn through the blower and distributed to each of the TED modules. The TEDs then heat or cool the air and direct it into the foam pad and manifold where it is distributed along the surface of the cushion and backrest of the seat. Once the system is activated, the DCSM uses a set of flexible algorithms to control the heating/cooling modes and the blower speed, dependant on the climate controlled seat switch settings.

• DTC B103C (Thermoelectric Driver Open Load) - If DCSM outputs to the driver seat backrest or cushion TED (circuit pins G, H, J or K at the DCSM connector) or any components within these circuit loops are open, disconnected or a TED resistance greater than 90, 000 ohms is sensed, the DCSM continues normal operation and sets this DTC.

This pinpoint test is intended to diagnose the following: 

• Wiring, terminals or connectors
• TED assembly
• DCSM