What Does B1492 Mean?
This code indicates the Body Control Module (BCM) has detected an open circuit in the ignition cylinder sensor wiring or the sensor itself. The ignition cylinder sensor monitors the position of the key in the ignition lock cylinder and communicates this information to the BCM for security and accessory functions. An open circuit means there is a break in the electrical path preventing proper signal transmission.
Common Causes
40%
Broken or damaged wiring between ignition cylinder sensor and BCM, often due to wear from steering column movement
30%
Failed ignition cylinder sensor internal circuit or mechanism
20%
Corroded or loose connector at ignition cylinder sensor or BCM
10%
Failed Body Control Module unable to read sensor signal
Diagnostic Steps
1
Step 1: Perform visual inspection of ignition cylinder sensor connector and wiring harness at steering column for obvious damage, corrosion, or disconnection. Check for chafing where wiring passes through steering column components.
2
Step 2: Using a digital multimeter, backprobe the ignition cylinder sensor connector and verify power and ground circuits per manufacturer specifications (typically 5V reference and ground). Check for continuity to BCM on signal wire with key removed.
3
Step 3: Disconnect ignition cylinder sensor and measure resistance across sensor terminals while rotating key through all positions (OFF, ACC, RUN, START). Compare readings to manufacturer specifications to verify sensor operation.
4
Step 4: If wiring and sensor test good, inspect BCM connector for corrosion, bent pins, or pushed-back terminals. Measure voltage/continuity at BCM side of circuit to isolate fault location.
5
Step 5: After repairs, clear codes, cycle ignition key through all positions multiple times, and verify code does not return. Test all key-related functions including accessory mode, anti-theft system, and starter engagement.
Estimated Repair Cost
$150 - $600
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected an open circuit in the ignition cylinder sensor wiring or the sensor itself. The ignition cylinder sensor monitors the position of the key in the ignition lock cylinder and communicates this information to the BCM for security and access...
The most common cause of B1492 (Ignition Cylinder Sensor Open Circuit) is: Broken or damaged wiring between ignition cylinder sensor and BCM, often due to wear from steering column movement
Typical repair costs for B1492 range from $150 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may experience no-start conditions, failure to turn off accessories, or anti-theft system malfunction. Generally safe to drive if vehicle starts and runs normally, but repair promptly to avoid being stranded or experiencing intermittent starting issues.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1492 to identify the root cause.
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Quick Info
Category
Body
System
Anti-theft and Ignition Control System
Difficulty
Type
Manufacturer
Recommended Tools
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