The P0025 – “B” Camshaft Position Timing Over-Retarded (Bank 2) code indicates a problem with the camshaft position timing, specifically noting that the camshaft timing on Bank 2 is more retarded (or delayed) than what the engine control module (ECM) has commanded.
P0025 quick overview
| Meaning | P0025 – “B” Camshaft Position Timing Over-Retarded (Bank 2) |
| Is it serious? | Yes, this code can lead to decreased engine performance, increased fuel consumption, and potentially serious engine damage if left unaddressed. |
| Possible causes | – Faulty camshaft position actuator solenoid – Incorrect oil viscosity or oil level – Timing chain wear or failure – Clogged oil passages affecting VVT operation – Electrical issues with the VVT circuit |
| How to diagnose? | Inspect the VVT system and camshaft solenoids for proper operation. Check oil level and quality to ensure they meet the engine’s requirements. Evaluate timing chain condition and tension. Examine electrical connections and wiring for damage or poor contacts. Perform a thorough diagnostic with appropriate scan tools and, if necessary, manual inspection. |
P0025 Meaning
The P0025 code triggers when the ECM detects that the exhaust camshaft in Bank 2 is positioned more retarded than it should be according to the current engine operation conditions. This misalignment can be caused by various factors, including faulty camshaft position actuator solenoids, worn timing components, or issues related to the engine’s oil condition and pressure.
Diagnosing this code often requires a multifaceted approach, examining both the mechanical and electrical components of the engine’s variable valve timing (VVT) system to pinpoint the exact cause of the issue.
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How to fix P0025 – learn from mechanics
I looked into P0025 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Mercedes P0025
Vehicle information 2008 Mercedes-Benz E350 4Matic 3.5L
Issue + repair history
- Check engine light on with no driveability issues observed
- Retrieved codes: P0303 and P0306 (Cyl #3 and #6 misfires), P0025 and P0015 (Exhaust camshaft adjustment incorrect position or late for left exhaust and right exhaust)
- No related repair history mentioned
Other OBD2 Codes + Test Results
- P0303: Cyl #3 misfire
- P0306: Cyl #6 misfire
- P0025: Continuous cam adjustment left exhaust
- P0015: Continuous cam adjustment right exhaust
Mechanic suggestions
- Replace all four camshaft solenoids (magnets) due to high failure rate and commonality of the issue
- Retrieve the engine number by inputting the VIN into the EPC program or contacting the dealer to verify if the TSB applies
- Consider replacing the wiring adapter of the cam adjustment solenoids as part of Service campaign 2012070002
- Replace both left and right exhaust camshaft solenoids to address the observed codes
- Be cautious of aftermarket scan tools like Autel, which may include tests that don’t accurately reflect manufacturer diagnostics
Final fix
- Replaced all four camshaft solenoids (magnets)
- Drove the vehicle for 30 miles after the repair without any codes recurring, indicating successful repair
Case #2: Audi P0025
Vehicle information 2002 Audi A4 Quattro 3.0L
Issue + repair history
- Engine surges at around 1000 RPM when at operating temperature
- Surging starts as random misfire and escalates to a full-on surge
- Throttle body cleaned, idle adaptation reset, no improvement
- Crankcase breather diaphragm replaced, no improvement
- MAF sensor replaced due to separate issue (P0102)
- Fuel pressure within spec, engine has sufficient power
- Coolant pump replaced, cam timing verified correct
- Loud hissing sound heard from throttle body area during surge
- P0025 code present before issue started
Other OBD2 Codes + Test Results
- P0025: Bank 2 Camshaft B Advance Set point not reached
- P0431: Bank 2 Warm-up catalyst efficiency below threshold
Mechanic suggestions
- Check vacuum line going to the brake booster for leaks
- Test dipstick tube for excessive vacuum
- Inspect crankcase pressure regulating valve (PCV) and canister purge valve for leakage
- Check hoses, intake gasket, and crankcase for vacuum leaks
- Replace catalytic converters and check crankcase vent system
- Use a smoke machine to check for vacuum leaks and test exhaust back pressure
- Consider performing a hard reset by disconnecting the battery terminals and crossing them to discharge capacitors
Final fix
- Replaced bank two exhaust cam sensor, resolving engine surging issue and eliminating P0025 code
Case #3: Audi P0025
Vehicle information 2003 Audi A6 Quattro 3.0L
Issue + repair history
- Surges at idle with a hot engine, often accompanied by a hissing air noise
- Oil pressure below specs, reads 24 psi hot idle and 40 psi hot at 2 K rpm
- Oil pump screen cleaned and correct oil used, oil pressure now close to specs
- Crankcase vent valve replaced
- Codes: P03305, P01999, P0025
Other OBD2 Codes + Test Results
- P03305: Bank 2 aft pos. sensor exhaust camshaft G301/G28 incorrect Allocation
- P01999: Friction too high code AZ
- P0025: B camshaft position sensor bank 2 timing over retarded
Mechanic suggestions
- Check cam to cam timing, as the chain may have jumped
- Inspect cam shaft timing chains and tensioners, known for failure and causing oil pressure issues
- Verify correct oil filter size and functioning oil pressure valve inside the filter housing
- Check the vanos function and cam timing, and clean the lower oil pan and pickup tube for sludge buildup
- Remove valve cover and look for weak tensioner on one or both sides of the engine
- Check for coking and sludge in the valve cover, which may indicate cam seizing and galled cam journal
- Remove air diverter from the center of the intake and clean it, as it may be sticking or broken
- Verify desired position of the cam timing solenoid and check for infrequent oil change intervals, which can lead to sludge buildup
- Prioritize checking the primary sensor affecting the area in question, which may need to be replaced if weak
Final fix
- Cleaning the oil pump screen and using the correct oil improved oil pressure, resolving the surging issue at idle. Replacing the crankcase vent valve may have also contributed to the fix.
How to diagnose P0025
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
| Diagnostic Step | Explanation |
|---|---|
| Inspect VVT solenoids and wiring | Check for proper operation of the camshaft solenoids and integrity of their connections. |
| Check oil level and viscosity | Ensure the oil meets the specifications required for VVT system functionality. |
| Evaluate timing chain and components | Look for signs of wear or damage that could affect camshaft timing. |
| Examine electrical connections | Inspect wiring and connectors for damage or poor contacts that might affect signal transmission. |
| Perform active testing and diagnostics | Use diagnostic tools to actively test solenoid function and verify camshaft position timing. |
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✅ Which OBD2 scanner is best?
✅ Which type should you get (DIY, Pro, Hobby)
✅ What is the best scanner for the exact brand/feature (e.g best for BMW)
✅ How to get a Bi-Directional tool for as cheap as $40
✅ Discount coupons for scanners
PDF is 100% free and it is designed to help you pick a scanner in less than a few minutes! Not a boring 50-page guide.
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