B1720

Step 1: Perform visual inspection of driver's seat wiring harness, checking for pinched, chafed, or damaged wires where harness routes under seat rails and at all connection points. Look for wire insulation damage contacting metal seat frame.

Step 2: Disconnect the driver's seat forward switch connector and measure resistance between the switch signal wire terminal (at harness side) and known good vehicle ground using a digital multimeter. Reading should be infinite ohms (open circuit); any continuity indicates wiring harness short to ground.

Step 3: If harness tests good, measure resistance across the seat forward switch terminals with switch disconnected. Compare readings to manufacturer specifications while actuating switch. Check for abnormal low resistance or continuity to switch housing ground indicating internal switch fault.

Step 4: Inspect all connector terminals for corrosion, moisture intrusion, bent pins, or pushed-back terminals. Clean connectors with electrical contact cleaner and apply dielectric grease. Check connector locking mechanisms for proper engagement.

Step 5: If all wiring and switch test good, monitor switch circuit voltage at module connector with seat control module disconnected using multimeter. Signal wire should show battery voltage or 5V reference with no ground path. Low voltage indicates module-side short.

Step 6: Clear codes, reconnect all components, and perform functional test of seat forward movement. Re-scan for codes to verify repair. Cycle seat through full range of motion multiple times to confirm intermittent faults are resolved.