P052B

What it means

P052B means the engine control unit has found that the intake (or 'A') camshaft on Bank 1 is sitting too far retarded compared with the target timing during a cold start, when the engine is running a fast-idle warm-up strategy. The ECU compares the camshaft position sensor signal against the crankshaft signal and sees the cam phasing lagging behind the commanded position beyond its allowed tolerance.

Symptoms

• Engine management warning light on
• Rough or unstable idle after a cold start
• Hesitation or reduced power while the engine is cold
• Poor fuel economy
• Rattling or ticking noise from the top of the engine on start-up
• Engine may run in a limp or reduced performance mode in some cases

Possible causes

• Low, dirty or incorrect-grade engine oil causing the variable valve timing actuator to respond slowlylikely
• Sticking or contaminated camshaft phasing (VVT) control solenoid or its oil screenlikely
• Faulty wiring or connector to the VVT solenoid or the camshaft position sensor (high resistance, corrosion, chafing)possible
• Worn or sticking camshaft phaser/actuatorpossible
• Stretched timing chain or worn tensioner/guides, or timing belt jumped a toothpossible
• Faulty camshaft or crankshaft position sensor giving a false readingrare
• Outdated or faulty engine control unit software, where a known issue exists for that enginerare

How to diagnose

1. Read all stored and pending codes and the freeze frame data, noting engine temperature, load and rpm when the code set
2. Check the engine oil level, condition and grade against the manufacturer specification, and look for sludge or contamination
3. Inspect the wiring and connectors at the VVT solenoid and camshaft and crankshaft sensors for damage, oil ingress and corrosion
4. Using a scan tool, compare commanded and actual camshaft angle at idle from cold and when warm, and watch whether the phaser responds to commands
5. Test the VVT solenoid resistance and operation, and check its supply, ground and control signal against the manufacturer's data
6. Remove and inspect the solenoid and its filter screen for debris or sludge, where the engine design allows
7. Check the cam and crank sensor signal patterns for correct correlation, and check for a known timing chain stretch check procedure for that engine
8. Check for relevant technical service bulletins or software updates for the specific model and engine

How to fix

• Change the oil and filter to the correct grade and specification, and correct the oil level
• Clean or replace the VVT control solenoid and its screen if blocked or faulty
• Repair or replace damaged wiring and connectors in the solenoid or sensor circuits
• Replace a faulty camshaft or crankshaft position sensor once testing confirms it
• Replace the camshaft phaser and, where worn, the timing chain, tensioner and guides, or correct the timing if it has jumped
• Apply a manufacturer ECU software update only where a known calibration fault is documented for the vehicle

Can I keep driving?

Nearby codes

• P052AGenericCold Start A Camshaft Position Timing Over-Advanced Bank 1
• P052CGenericCold Start A Camshaft Position Timing Over-Advanced Bank 2