LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> GMC >> 2018 >> Acadia Denali, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 329 (Object Detection System And Pedestrian Protection System) >> Diagnostic Information and Procedures >> DTC B356A: Vehicle Direction Warning Switch Circuit >> Circuit/System Testing - Without UGN
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing - Without UGN

WARNING: This page is about a different car, the 2017 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S70A Steering Wheel Controls Switch - Left Lower.
  2. Ignition ON.
  3. Verify the scan tool Vehicle Direction Warning Switch Status parameter is Open.
    • If not Open 
    1. Ignition OFF, disconnect the harness connector at the B174W Frontview Camera - Windshield.
    2. Test for infinite resistance between the S70A Steering Wheel Controls Switch - Left Lower signal circuit terminal 1 and ground.
    • If less than infinite resistance, repair the short to ground on the circuit.
    • If infinite resistance, replace the B174W Frontview Camera - Windshield.
    • If Open 
  4. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
  5. Verify within 10 s the scan tool Vehicle Direction Warning Switch Status parameter is Closed.
    • If not Closed 
    1. Ignition OFF, disconnect harness connector at the B174W Frontview Camera - Windshield. Ignition ON.
    2. Test for less than 1 V between the S70A Steering Wheel Controls Switch - Left Lower signal circuit terminal 1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V.
    3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the B174W Frontview Camera - Windshield.
    • If Closed 
  6. Test or replace the S70A Steering Wheel Controls Switch - Left Lower.