P001C

What it means

P001C means the engine control unit has detected a high-voltage fault in the control circuit for the bank 1 camshaft profile actuator 'A'. This is the device that changes cam profile or valve lift on systems fitted with variable profile control. The control unit saw a circuit voltage higher than expected for the commanded state, which points to a short to voltage, an open circuit or a fault in the actuator or driver. The exact layout and actuator type depend on the engine.

Symptoms

• Engine warning light on
• Reduced power or the engine going into a limited-performance mode
• Rough idle or uneven running
• Poor fuel economy
• Hesitation or flat spots during acceleration
• Possible hard starting or stalling, depending on the engine

Possible causes

• Wiring fault in the actuator control circuit, such as a short to a power supply or a chafed or damaged wirelikely
• Corroded, loose or damaged connector at the actuator or control unitlikely
• Faulty camshaft profile actuator or solenoid, with an internal open or short circuitlikely
• Open circuit in the control or return wire, which can read as high voltagepossible
• Low or contaminated engine oil, or oil flow problems affecting the actuator's operationpossible
• Faulty driver circuit inside the engine control unitrare
• Outdated control unit software where the manufacturer has issued a revision for this faultrare

How to diagnose

1. Read all stored and pending codes and note the freeze frame data, such as engine speed, load, temperature and battery voltage. Look for related cam timing or position codes.
2. Check the engine oil level and condition, and check the service history for oil changes, since the actuator relies on clean oil.
3. Visually inspect the bank 1 actuator wiring and connector for chafing, heat damage, oil contamination, corrosion and poor terminal tension.
4. Check the battery and charging system voltage, as unstable supply can cause circuit faults.
5. Back-probe or disconnect and test the actuator supply and control wires with a multimeter against the wiring diagram for that engine, checking for short to voltage, open circuit and high resistance.
6. Measure the actuator coil resistance and compare it with the manufacturer specification for that engine.
7. Use a scan tool to command the actuator, if supported, and watch the response and any change in the circuit status or cam timing data.
8. Clear the code, road test and recheck. If the fault returns with wiring and actuator proven good, check for a relevant software update and have the control unit checked.

How to fix

• Repair or replace damaged wiring, and fix any short to voltage or open circuit found.
• Clean or replace the faulty connector or terminals, and ensure a secure fit.
• Replace the camshaft profile actuator if its resistance or operation is out of specification.
• Correct the engine oil level, and change the oil and filter to the specified grade if it is dirty or incorrect.
• Update the control unit software only if the manufacturer lists it as a fix for this fault.
• Repair or replace the control unit only after wiring and actuator have been proven good.

Can I keep driving?

Nearby codes

• P001BGenericA Camshaft Profile Actuator A Control Circuit Low Bank 1
• P001DGenericA Camshaft Profile Actuator A Control Circuit/Open Bank 2