What Does B1353 Mean?
B1353 indicates the Body Control Module (BCM) has detected an open circuit in the ignition key-in switch circuit. This system monitors whether a key is physically inserted in the ignition cylinder and typically controls functions like the key-in-ignition warning chime, door lock/unlock behavior, and anti-theft features. An open circuit means the BCM is not receiving the expected signal when a key should be detected in the ignition.
Common Causes
45%
Faulty ignition key-in switch or cylinder sensor mechanism
30%
Broken, corroded, or disconnected wiring between ignition cylinder and BCM
15%
Failed or corroded connector at ignition cylinder or BCM
10%
BCM internal fault or corrupted programming
Diagnostic Steps
1
Step 1: Perform visual inspection of ignition cylinder area and locate the key-in switch connector. Check for obvious damage, disconnected connectors, chafed wiring, or corrosion at terminals
2
Step 2: With key removed from ignition, use a digital multimeter to test continuity of the key-in switch circuit from the ignition cylinder connector back to the BCM connector. Refer to wiring diagram for specific pin assignments. Expect less than 1 ohm resistance on intact wiring
3
Step 3: At the ignition cylinder switch connector (disconnected), manually test the key-in switch operation by inserting the key and measuring resistance change across the switch terminals. Should show open circuit (infinite resistance) with no key, and closed circuit (near 0 ohms) with key inserted
4
Step 4: Check voltage supply and ground at the key-in switch circuit using multimeter. Verify BCM is providing proper reference voltage (typically 5V or 12V depending on manufacturer) and clean ground path
5
Step 5: If all wiring and switch tests pass, inspect BCM connectors for corrosion, bent pins, or moisture intrusion. Check BCM grounds and power supplies
6
Step 6: Clear codes and perform functional test by inserting and removing key while monitoring live data for key-in signal status. Verify repair by confirming key-in chime operates and no code returns
Estimated Repair Cost
$75 - $450
Parts + labor, varies by vehicle and location
B1353 indicates the Body Control Module (BCM) has detected an open circuit in the ignition key-in switch circuit. This system monitors whether a key is physically inserted in the ignition cylinder and typically controls functions like the key-in-ignition warning chime, door lock/unlock behavior, and...
The most common cause of B1353 (Ignition Key-In Circuit Open) is: Faulty ignition key-in switch or cylinder sensor mechanism
Typical repair costs for B1353 range from $75 to $450, 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 systems and is safe to continue driving. The primary concern is loss of convenience features like key-in-ignition warning chimes, which may lead to leaving keys in the vehicle or draining the battery if accessories remain powered.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1353 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 Systems
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
