Ignition Run/Start Circuit Short To Ground
Code B1558 indicates a diagnostic fault in the Body Systems (Lighting, Windows & Comfort) (Ignition Run/Start Circuit Short To Ground). Connect an OBD2 scanner to verify freeze frame data, then test circuit voltage and vacuum connections before replacing components.
Inspect the electrical harness and ground connection related to B1558. Clear the code with an OBD2 scanner; if it returns, perform a multimeter resistance check on the primary sensor.
Symptoms Associated with B1558
Drivers typically observe the following symptoms when the ECM flags B1558:
Common Root Causes & Statistical Probability Matrix
Statistical breakdown of what triggers this code based on automotive repair shop data.
Step-by-Step Diagnostic & Repair Procedure
Follow this logical order to isolate and repair B1558 before spending money on costly parts.
Step 1: Scan and Record Freeze Frame Data
Connect an OBD2 scanner, record engine RPM, coolant temp, and secondary DTCs associated with B1558.
Step 2: Visual Inspection
Inspect wiring harnesses, pins, and vacuum lines related to the Body Systems (Lighting, Windows & Comfort) for chafing, oil contamination, or burn marks.
Step 3: Multimeter / Component Verification
Measure 12V reference power, ground continuity, and signal voltage against factory service manual specifications for B1558.