P1294: High Side Open Bank 2 (Left)
The P1294 code indicates that the powertrain control module (PCM) has detected an open circuit in the high-side driver for the left bank (Bank 2) of the engine. This high-side driver controls power to various actuators such as fuel injectors, ignition coils, or solenoids. An open circuit means there is a break in the wiring or a failed component, preventing proper voltage supply. This can cause misfires, rough running, or no-start conditions.
1. Symptoms You Will Notice
- Engine misfire or rough idle
- Check Engine Light illuminated
- Reduced engine power or hesitation
- Possible no-start condition
2. Most Common Causes
- Faulty or damaged cylinder head temperature (CHT) sensor
- Open circuit in the CHT sensor wiring
- Short to voltage in the CHT sensor signal wire
- Corroded, damaged, or bent pins in the CHT sensor connector
- Poor ground connection in the sensor reference circuit
- Internal failure of the powertrain control module (PCM)
3. Step-by-Step Diagnosis
Step 1: Use a scan tool to confirm P1294 and check for related codes.
Step 2: Visually inspect wiring and connectors for Bank 2 components for damage or corrosion.
Step 3: Test the high-side driver circuit with a multimeter for continuity and voltage.
Step 4: If wiring is intact, test the actuator (e.g., injector) resistance and operation.
Step 5: If all else fails, suspect a faulty PCM and perform a bench test or replacement.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended. The open circuit can cause engine misfires, reduced power, or stalling, which may lead to unsafe driving conditions or further engine damage.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for diagnosis and simple wiring repairs. If the PCM needs replacement, costs can exceed $500.
5. Commonly Affected Makes
This is a manufacturer-specific code. The exact manufacturer is not confirmed in our current database.