B1364: Ignition Start Signal Circuit Open
The B1364 code indicates that the powertrain control module (PCM) or security module has detected an open circuit in the ignition start signal circuit. This circuit carries the electrical signal that tells the module the key is in the START position. An open circuit prevents the module from receiving this signal, which can affect the immobilizer system, starter relay operation, or vehicle security logic. In Ford vehicles, this code is typically associated with the Passive Anti-Theft System (PATS) or the security control module (SCM).
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or worn ignition switch
- Open or corroded wiring in the start signal circuit
- Loose or damaged ignition switch connector
- Failed security control module (SCM) or PATS module
- Blown fuse related to the start circuit
- Starter relay with open coil or bad contacts
- Faulty key transponder antenna (PATS-related)
3. Symptoms You Will Notice
- Engine cranks but does not start
- No crank condition
- Security light flashing or staying on
- Starter relay does not engage
4. Step-by-Step Diagnosis
Check for blown fuses in the start circuit
Inspect ignition switch connector for damage or corrosion
Test continuity of the start signal wire from ignition switch to PCM/security module
Verify starter relay operation and coil resistance
Check for PATS-related faults using a scan tool
Test key transponder antenna if PATS is suspected
5. Frequently Asked Questions
Is it safe to drive?▼
It is not recommended to drive with this code, as the vehicle may not start or may stall unexpectedly. The severity is medium, and the issue should be diagnosed promptly.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on the cause. A faulty ignition switch may cost $150-$250, while a PATS module replacement can exceed $500.