Ignition Start Circuit Malfunction
The B1363 code indicates a fault in the ignition start circuit, which is monitored by the PCM or BCM. This code sets when the module detects an open circuit, short to ground, short to voltage, or abnormal resistance in the circuit that carries the start signal from the ignition switch to the starting system. As a result, the engine may not crank or start because the control module does not receive or cannot validate the start command.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty ignition switch or worn contacts in the START position
- Open or short circuit in the ignition start circuit wiring
- Corroded, loose, or damaged connectors or terminals in the start signal circuit
- Defective starter relay or solenoid
- Excessive resistance in the circuit wires or connection points
- Internal failure of the PCM or BCM
3. Symptoms You Will Notice
- Engine does not crank when the key is turned to START
- Engine cranks but does not start
4. Step-by-Step Diagnosis
Check for blown fuses related to the ignition start circuit
Inspect the ignition switch for proper operation and continuity in the START position
Test the start signal circuit for open, short, or high resistance using a multimeter
Examine connectors and wiring for corrosion, damage, or loose connections
Test the starter relay and solenoid for proper function
If all else is normal, check for PCM or BCM faults
5. Frequently Asked Questions
Is it safe to drive?▼
No, this is a high-severity issue. The vehicle may not start or may stall unexpectedly, posing a safety risk. It should be diagnosed and repaired immediately.
How much does it cost to fix?▼
The repair cost typically ranges from $100 to $400, depending on the root cause. Replacing an ignition switch can cost $150-$300, while wiring repairs may be $100-$200. PCM/BCM replacement is more expensive, often $500-$1000.