B1513

Step 1: Perform a visual inspection of the DIC switch on the steering column or dashboard, checking for physical damage, stuck buttons, or signs of liquid intrusion. Test switch operation manually while observing live data for switch state changes in the scan tool.

Step 2: Locate and disconnect the DIC switch connector. Using a digital multimeter, measure resistance across each switch terminal to ground while actuating each button position. Compare readings to factory specifications (typically open circuit when not pressed, near 0 ohms or specific resistor values when pressed).

Step 3: With connector still disconnected, inspect both male and female terminals for corrosion, bent pins, or spread terminals. Clean contacts with electrical contact cleaner and apply dielectric grease. Check connector lock mechanism for proper retention.

Step 4: Trace the wiring harness from the DIC switch to the BCM, inspecting for chafing points, pinched wires near steering column tilt mechanisms, or damage from previous repairs. Use multimeter to perform continuity tests on all circuit wires and check for shorts to ground or power.

Step 5: With ignition on, measure voltage at the switch connector supply wire (typically 5V or 12V reference). Verify ground circuit has less than 0.1V drop to battery negative. If supply voltage or ground is incorrect, diagnose BCM power distribution or ground circuits.

Step 6: If all circuits test normal, perform a switch substitution test with a known-good DIC switch or clear codes and monitor for recurrence. If fault persists with new switch and verified wiring, suspect BCM internal fault requiring module replacement or reprogramming.