Serial Communication Circuit Test

When tilt/telescopic ECU receives an input from memory or return switches, serial data is sent back and forth between tilt/telescopic ECU and driver's seat ECU. Check White and Black wires between tilt/telescopic ECU and driver's seat ECU for short or open. See WIRING DIAGRAMS . See MULTIPLEX COMMUNICATION SYSTEMS - GS300 & GS400 article. If circuits are okay, return to TROUBLE SHOOTING .