B1756

Step 1: Perform visual inspection of hazard switch, flasher relay, and all associated wiring harnesses for obvious damage, pinched wires, burned connectors, or areas where harness contacts metal. Pay special attention to areas near sharp edges and moving components.

Step 2: Disconnect the hazard flasher relay or switch connector. Using a digital multimeter, measure resistance between the BCM output circuit wire (hazard control wire) and known good ground. Reading should be greater than 10K ohms; low resistance confirms short to ground is downstream of BCM.

Step 3: If short exists with relay/switch disconnected, systematically disconnect connectors along the hazard circuit moving toward BCM, measuring resistance to ground at each point to isolate the location of the short in the wiring harness.

Step 4: If no short is found in wiring, reconnect harness and test hazard switch and relay individually. Apply voltage to relay coil and measure output terminal continuity; test switch with ohmmeter for proper contact function and no unintended ground paths.

Step 5: If all external components test good, suspect BCM output driver failure. With all components disconnected, measure resistance from BCM hazard output pin to ground at BCM connector; should be very high resistance (typically 1M ohm or higher).

Step 6: After repair, clear codes, reconnect all components, and activate hazard lights multiple times to verify proper operation and confirm code does not return.