P34AA

What it means

P34AA means the engine control unit has seen a signal that is too low (a short to ground or very low voltage) in the temperature sensor circuit for the 'A' camshaft position actuator on bank 2. The reading is outside the range the sensor should give, so the control unit cannot trust the actuator temperature data. Which camshaft counts as 'A', and how the sensor is built into the actuator, depends on the engine.

Symptoms

• Engine warning light on with P34AA stored
• Rough idle or uneven running, particularly when cold
• Reduced power or flat response as variable valve timing defaults to a safe setting
• Slightly higher fuel consumption
• Possible additional valve timing or camshaft correlation codes stored

Possible causes

• Damaged, chafed or water-contaminated wiring between the actuator or sensor and the control unit, shorted to groundlikely
• Corroded, loose or oil-soaked connector at the bank 2 camshaft actuatorlikely
• Faulty camshaft position actuator or its integrated temperature sensor (where fitted)possible
• Oil leak into the connector or harness causing a low-resistance pathpossible
• Poor ground or reference supply fault affecting the sensor circuitpossible
• Fault in the engine control unit's sensor inputrare

How to diagnose

1. Read all stored codes and freeze frame data, noting engine temperature and running conditions when the fault set, and check for other valve timing codes
2. Clear the code and see whether it returns straight away (a hard fault) or only intermittently (suggesting wiring or connector movement)
3. Visually inspect the bank 2 camshaft actuator connector and harness for chafing, heat damage, oil contamination, corrosion and bent or pushed-back pins
4. Check the harness routing near the cylinder head for rubbing against brackets or hot components
5. Using the manufacturer's wiring diagram, test the sensor circuit for a short to ground and check the reference and ground supplies
6. With the connector unplugged, check the actuator or sensor resistance against the manufacturer's specification for your engine
7. View live actuator temperature data and compare it with coolant or oil temperature, watching for implausible values while wiggling the harness
8. Check the engine oil level and condition, as the actuator depends on correct oil supply and pressure

How to fix

• Repair or replace damaged wiring and any shorted section of the harness
• Clean, dry and refit the connector, or replace the connector or terminals if corroded or damaged
• Replace the bank 2 camshaft position actuator or sensor if its readings are out of specification
• Fix any oil leak feeding into the connector or harness, and replace contaminated wiring
• Repair the faulty ground or supply connection found during testing
• Only if all else is sound, check for a control unit software update or fault, following manufacturer procedures

Can I keep driving?

Nearby codes

• P34A9GenericA Camshaft Position Actuator Temperature Sensor Range/Performance Bank 2
• P34ABGenericA Camshaft Position Actuator Temperature Sensor Circuit High Bank 2