What Does B1352 Mean?
This code indicates the Body Control Module (BCM) has detected a fault in the ignition key-in detection circuit. This circuit monitors whether the key is inserted in the ignition cylinder and signals the BCM to activate warning chimes, interior lights, and other key-related functions. The BCM has identified an open circuit, short circuit, or loss of signal from the key-in switch.
Common Causes
45%
Faulty or worn ignition key cylinder switch or key-in sensor
30%
Damaged, corroded, or disconnected wiring harness between ignition cylinder and BCM
15%
Failed or malfunctioning Body Control Module (BCM)
10%
Blown fuse or open circuit in key-in switch power supply
Diagnostic Steps
1
Step 1: Perform visual inspection of ignition cylinder and surrounding wiring harness for obvious damage, disconnected connectors, or corrosion at the key-in switch connector. Check all related fuses in the BCM and ignition switch circuits with a test light or multimeter.
2
Step 2: With key removed from ignition, use a multimeter to test continuity and voltage at the key-in switch connector. Verify reference voltage (typically 5V or 12V) is present on the power supply wire per manufacturer specifications.
3
Step 3: Insert key into ignition cylinder and monitor the key-in switch signal wire with a multimeter. The signal should change state (high to low or low to high depending on system design) when key is inserted. If no change occurs, suspect faulty key-in switch.
4
Step 4: Disconnect the BCM connector and check for continuity between the key-in switch and BCM terminal. Resistance should be less than 5 ohms. Also check for shorts to ground or power on the signal wire.
5
Step 5: If all wiring and switch tests pass, perform BCM functionality test using bidirectional controls if available. Monitor BCM inputs in live data to verify proper signal reception. Replace BCM if it fails to recognize valid key-in switch signals.
6
Step 6: After repair, clear codes and verify proper operation of key-in warning chime, interior lights activation, and other key-related functions. Road test and confirm code does not return.
Estimated Repair Cost
$75 - $600
Parts + labor, varies by vehicle and location
This code indicates the Body Control Module (BCM) has detected a fault in the ignition key-in detection circuit. This circuit monitors whether the key is inserted in the ignition cylinder and signals the BCM to activate warning chimes, interior lights, and other key-related functions. The BCM has id...
The most common cause of B1352 (Ignition Key-In Circuit Failure) is: Faulty or worn ignition key cylinder switch or key-in sensor
Typical repair costs for B1352 range from $75 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This code does not affect vehicle drivability or safety. The vehicle can be driven normally, but warning chimes may not function properly and you may not receive alerts when keys are left in the ignition, potentially leading to dead battery situations.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1352 to identify the root cause.
OBDHut Mobile App
Scan codes directly from your car with the OBDHut app.
Coming Soon
Quick Info
Category
Body
System
Body Control and Accessory System
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
