Power Seat System Test

Following are tests that will help to diagnose the hard wired components and circuits of the power seat system. However, if the vehicle is also equipped with the optional memory system, these tests may not prove conclusive in the diagnosis of the driver side power seat. In order to obtain conclusive testing of the driver side power seat with the memory system option, the Programmable Communications Interface (PCI) data bus network and all of the electronic modules that provide inputs to, or receive outputs from the memory system components must be checked.

The most reliable, efficient, and accurate means to diagnose the driver side power seat with the memory system option requires the use of a DRB III scan tool and the proper Diagnostic Procedures manual. The DRB III scan tool can provide confirmation that the PCI data bus is functional, that all of the electronic modules are sending and receiving the proper messages on the PCI data bus, and that the memory system is receiving the proper hard wired inputs and relaying the proper hard wired outputs to perform its driver side power seat functions.

WARNING: SOME VEHICLES ARE EQUIPPED WITH SEATBACK MOUNTED AIRBAGS. BEFORE ATTEMPTING TO DIAGNOSE OR SERVICE ANY SEAT OR POWER SEAT SYSTEM COMPONENT YOU MUST FIRST DISCONNECT AND ISOLATE THE BATTERY NEGATIVE CABLE. THEN WAIT TWO MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO DO SO COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. If the driver power seat exhibits a interrupted or jerky motion, there is a possibility that the wires leading from the memory seat module to the memory seat motor are mis-wired. To check the concern, obtain a DRB III scan tool and energize each axis one at a time. If any axis stops in approximately 2 seconds (without hitting the end of travel), the feedback for that axis may have an open, short or be mis-wired. Check the wiring to that axis (module to motor). Fix any wiring problems and retry that axis.
2. If any power seat is not operational in any direction, check the power seat circuit breaker, located under the trailing edge of the appropriate power seat. Refer to the Power Distribution section of this service manual for the circuit breaker diagnosis and testing procedure.
3. If the power seat circuit breaker is OK, check for proper 12v and ground connections at the power seat switch and/or memory seat module. Fix any wiring problems and retry
4. Check the power seat system wire harness connections and pins to ensure proper circuit continuity and ground paths. For complete circuit diagrams, refer to Wiring Diagrams.
5. With the dome lamp on, apply the power seat switch in the direction of the failure. If the dome lamp dims, the seat may be jamming. Check under and behind the seat for binding or obstructions. If the dome lamp does not dim, proceed with testing of the individual components and circuits in the power seat system.