P0025 on 2020-2021 Ford Transit: Exhaust Cam Timing Causes and Fixes

What's Unique About the 2020-2021 Ford TRANSIT

Ford's 3.5L V6 engine family, used in the Transit and its platform mates like the F-150 and Explorer, has a well-documented sensitivity in its Variable Camshaft Timing (VCT) system. Ford has issued multiple service bulletins, like SSM 50067, specifically mentioning that small debris in the oil can cause the VCT solenoids to stick, triggering codes like P0025. This isn't a random failure, but rather a known weak point where oil quality, correct viscosity, and maintenance are critical to preventing issues. TSB 16-0038 also noted that for low-mileage 2016 Transits (and other 3.5L GTDI vehicles), a P0025 paired with P0019 specifically called for the replacement of the Bank 2 exhaust VCT solenoid, highlighting how common this specific part failure is.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Rough or unstable idle
• Engine is hard to start.
• Reduced engine power and acceleration.
• Engine may hesitate or stall, especially when coming to a stop.
• Decreased fuel economy.
• Engine knocking, ticking, or rattling noises.

Most Likely Causes

1. Low, Incorrect, or Dirty Engine Oil 🔴 High Probability The VCT system is hydraulic and highly sensitive to oil pressure and cleanliness. Ford TSB SSM 50067 directly mentions that 'small debris' can cause VCT solenoids to stick. Using oil of the wrong viscosity or going too long between oil changes can lead to sludge and debris that clog the solenoid's fine mesh screens.
   How to confirm: Check the oil level on the dipstick and inspect its color and consistency. If the level is low or the oil is dark, sludgy, or past its service interval, it needs to be changed. This is the mandatory first step before any parts are replaced.
   Typical fix: Perform an engine oil and filter change using the Ford-specified Motorcraft full-synthetic oil (check owner's manual for correct viscosity, typically 5W-30) and a Motorcraft filter. Clear the code and test drive to see if it returns.
   Est. part cost: $50-$100
2. Failing Bank 2 Exhaust VCT Solenoid 🔴 High Probability → Shop Engine Variable Valve Timing (VVT) Solenoid This is the most common part to fail for this code. The solenoid gets clogged with debris or fails electrically, preventing it from properly directing oil flow to the cam phaser. TSB SSM 50067 acknowledges this common failure and even provides a diagnostic procedure (Pinpoint Test HK12) to cycle the solenoid with a scan tool to try and dislodge debris before replacement.
   How to confirm: After an oil change, if the code persists, use a scan tool to command the solenoid on and off (Pinpoint Test HK12). A definitive test is to swap the Bank 2 exhaust solenoid with the Bank 2 intake solenoid. Clear codes and drive. If the code changes to P0021 (Intake 'A' Camshaft Position Timing - Over-Advanced Bank 2), the solenoid is confirmed as the faulty part. You can also test its resistance with a multimeter, which should be around 6.9-7.9 ohms. 🎬 Watch: How to test your VVT solenoid with a multimeter
   Typical fix: Replace the Bank 2 (driver's side) exhaust VCT solenoid. The valve cover must be removed to access it.
   Est. part cost: $50-$150
3. Failed Camshaft Phaser 🟡 Medium Probability → Shop Engine Camshaft The 3.5L engine family is known for cam phaser issues, which can cause a startup rattle and eventually lead to timing codes. TSB 23-2143 (which supersedes 22-2200) specifically addresses a cold start rattle on 3.5L EcoBoost engines due to worn VCT units (phasers). The phaser can get stuck mechanically, preventing it from adjusting timing correctly.
   How to confirm: This is a more advanced diagnosis. If a new solenoid doesn't fix the code, and you hear a distinct rattling noise from the front of the engine for 2-5 seconds on a cold start, a failing phaser is a strong possibility. 🎬 Watch: Hear the specific rattle caused by failing cam phasers Diagnosis requires checking timing chain components and is best left to a professional.
   Typical fix: Replace the camshaft phasers, timing chain, and tensioners. This is a labor-intensive job often costing thousands of dollars.
   Est. part cost: $400-$800

Rare But Worth Checking

• Worn Timing Chain or Guides: → Shop Engine Timing Chain While chain stretch can occur over 100,000 miles, it's less likely to be the root cause for only a P0025 code without other symptoms like significant rattling or correlation codes like P0019. It's often replaced as part of a larger timing job with the phasers.
• Faulty Camshaft Position Sensor: → Shop Engine Camshaft Position Sensor It's possible for the sensor to send incorrect data, but this is rare. A faulty sensor would often be accompanied by other sensor-specific circuit fault codes (e.g., P0365, P0369), not a mechanical correlation code like P0025.
• Clogged Oil Passages: In cases of severe engine sludge from neglected oil changes, the oil passages leading to the VCT system can become blocked, starving the components of oil pressure. This usually indicates a more widespread engine health problem.

Diagnosis Steps

1. Verify the code is present using an OBD-II scanner.
2. Check the engine oil level and condition. If low, dirty, or the wrong viscosity, perform an oil and filter change with Ford-specified products. This is the most critical first step.
3. If the code returns, inspect the wiring harness and connector for the Bank 2 (driver's side) exhaust VCT solenoid for any damage, corrosion, or oil contamination.
4. Using a capable scan tool, monitor the desired vs. actual camshaft timing for the Bank 2 exhaust cam (VCT_EXH_ACT_B2 vs VCT_EXH_CMD_B2). Command the solenoid to activate (Pinpoint Test HK12 from TSB SSM 50067) and see if the actual timing changes.
5. If the solenoid does not respond or the code returns, perform a solenoid swap. Exchange the Bank 2 exhaust solenoid with the Bank 2 intake solenoid. If the code changes to P0021, you have confirmed the solenoid is the faulty component.
6. If the solenoid is confirmed bad, replace it. It is located under the valve cover. Many owners choose to replace all four VCT solenoids at once as a preventative measure.
7. If a new solenoid does not resolve the issue, the problem is likely deeper in the timing system, such as a faulty cam phaser or a stretched timing chain. Listen for a cold-start rattle. This level of diagnosis and repair is more complex and may require a professional.

Parts You'll Likely Need

• Engine Variable Valve Timing (VCT) Solenoid (OEM #HL3Z-6M280-A) — This is the most common part to fail for code P0025. It gets stuck from oil debris or fails electrically, preventing proper timing adjustments. TSBs from Ford confirm this is a known issue.
  Trusted brands: Motorcraft, Dorman, NTK
  OEM price range: $35-$70
  Aftermarket price range: $25-$50
• Engine Oil and Filter — The VCT system is hydraulic. Clean oil of the correct viscosity is the first and most critical step in diagnosis and can sometimes fix the issue alone. Using high-quality full-synthetic oil and a Motorcraft filter is highly recommended.
  Trusted brands: Motorcraft
  OEM price range: $60-$100
  Aftermarket price range: $40-$70
• Valve Cover Gasket Set — The VCT solenoids are located under the valve covers. The gaskets are typically replaced whenever the valve covers are removed to ensure a proper seal.

Related Codes That Often Appear With This One

• P0015 — This is the equivalent code for 'B' Camshaft Position - Timing Over-Retarded on Bank 1 (passenger side). Seeing both P0015 and P0025 strongly suggests a systemic issue like old/low oil or low oil pressure affecting both banks.
• P0024 — This code is for 'B' Camshaft Position - Timing Over-Advanced on the same bank (Bank 2). Seeing them together could point to an erratic VCT solenoid or a severe oil flow problem causing unpredictable cam movement.
• P0019 — This is a crankshaft/camshaft correlation code for Bank 2, Sensor B (Exhaust). It often appears with P0025 and points towards a more serious base timing issue like a stretched timing chain or a failed cam phaser. TSB 16-0038 specifically calls out this pair on low-mileage engines as requiring a new VCT solenoid.

Technical Service Bulletins (TSBs) & Recalls

• SSM 50067 - Illuminated MIL with various VCT DTCs, possibly due to debris in VCT solenoid.
• SSM 54366 - Update to pinpoint test procedures for a range of VCT codes including P0025.
• TSB 16-0038 - For low-mileage 3.5L GTDI engines, directs replacement of Bank 2 exhaust VCT solenoid if P0019 and P0025 are present together.
• TSB 22-2200 / 23-2143 - Addresses cold-start rattle from worn VCT units (phasers) on 3.5L EcoBoost engines.

Platform-Specific Known Issues

• TSB SSM 50067: Ford acknowledges that P0025 (and other VCT codes) may be caused by small debris making the VCT solenoid stick. It advises running a scan tool diagnostic (Pinpoint Test HK12) to cycle the solenoid 10 times to attempt to clear debris before component replacement.
• TSB SSM 54366: Notes that the diagnostic pinpoint test (HK) for this family of codes has been updated in the official workshop manual, indicating this is a common area of concern for Ford that requires revised diagnostic procedures.
• TSB 16-0038: Specifically for low-mileage 2016 3.5L GTDI engines (including Transit), this bulletin states that if codes P0019 and P0025 are found together, the Bank 2 exhaust VCT solenoid should be replaced, pointing to a known early-life failure pattern.

Mechanic-Grade Diagnostic Values

• VCT Solenoid Resistance — expected: 6.9 to 7.9 ohms at 68°F (20°C). Some sources state a wider acceptable range of 5-14 ohms.. Failure: A reading that is open (infinite resistance), shorted (near zero ohms), or significantly outside the specified range.
• VCT Solenoid Power Supply Voltage — expected: Battery voltage (approx. 12.6V with key on, engine off) at the power feed wire of the solenoid connector.. Failure: Low or no voltage indicates a wiring issue, a blown fuse, or a problem with the PCM power relay.
• Mode $06, Test ID $81, Component ID $12 (example) — expected: The measured value should be within the MIN and MAX limits specified by the PCM.. Failure: A measured value exceeding the maximum limit confirms an over-retarded condition, validating the P0025 code.
• Scan Tool PID: VCT_EXH_ERR_B2 (Bank 2 Exhaust Cam Error) — expected: Should be close to 0 degrees at idle and respond quickly when the VCT solenoid is commanded by the scan tool.. Failure: A persistently high positive or negative value, or a value that does not change when the solenoid is commanded, points to a stuck solenoid or phaser.

Hidden / Shadow Codes Worth Checking

• Mode $06 Test Results: While not a 'shadow code' in the traditional sense, Mode $06 data provides raw test results from the PCM's non-continuous monitors. For P0025, there will be a specific Test ID (TID) and Component ID (CID) for the Bank 2 exhaust camshaft phase angle. A failing result in Mode $06 can confirm the fault before the PCM has completed enough drive cycles to illuminate the MIL again. (see via Most mid-range and professional OBD-II scan tools can access Mode $06 data.)

Scan Tool Commands That Help

• Ford IDS (or equivalent like FORScan): VCT System and Solenoid Test (part of Pinpoint Test HK) — This bidirectional control allows the technician to command the VCT solenoid's duty cycle from 0-100% while monitoring the actual cam position and error PIDs (e.g., VCT_EXH_ERR_B2). It is the definitive test to determine if a solenoid is electrically responsive but mechanically stuck, or completely non-responsive, without removing it from the engine.

Wiring & Ground Locations

• Bank 2 Exhaust VCT Solenoid Connector — On the top of the driver's side valve cover, plugging into the rearmost solenoid.. This is the primary point for electrical testing. The power feed wire (often Violet/Orange) should have battery voltage with the key on. The control wire (often Brown/Green) is pulsed to ground by the PCM. A damaged connector or wiring here will directly cause a fault.
• PCM Connector C1551E (example) — One of the main connectors at the Powertrain Control Module (PCM), typically located in the engine bay.. This is where the control signal originates. Verifying the pulsed ground signal at this connector with an oscilloscope can confirm if the PCM driver is functioning correctly, ruling out a bad PCM.
• G104 (or similar designation) — A primary engine/PCM ground point, often a stud on the engine block, cylinder head, or transmission case.. The PCM controls the VCT solenoids by switching their ground circuit. A poor, corroded, or loose main engine ground can create a floating ground reference, causing erratic voltage and unpredictable behavior in all PCM-controlled actuators, including the VCT solenoids.

Real Owner Repair Stories

• Ford F150 Forum (2018 Ford F-150 3.5L EcoBoost) — Check engine light with P0025 and a slight rough idle.
  ❌ Tried (didn't work) Performed an oil and filter change.
  ✅ What actually fixed it The owner swapped the Bank 2 intake and exhaust VCT solenoids. The code changed to P0021 (Intake timing fault). This confirmed the original exhaust solenoid was faulty. Replacing the bad solenoid with a new part (OEM # BL3Z-6M280-B, which is an older version of the current part) resolved the P0025 code permanently.
• fordtransitusaforum.com (2020 Ford Transit 3.5L EcoBoost) — Check Engine Light with code P0025.
  ❌ Tried (didn't work) Oil and filter change.
  ✅ What actually fixed it The owner took the vehicle to a dealer who diagnosed and replaced the Bank 2 (driver's side) exhaust VCT solenoid. This fixed the issue. Another user in the same discussion noted that on their similar engine, a second solenoid failed shortly after the first, and recommended replacing all four solenoids at the same time as a preventative measure.

OEM Part Supersession History

• BL3Z-6M280-A / BL3Z-6M280-B → HL3Z-6M280-A — The updated HL3Z-6M280-A solenoid features design improvements, including finer mesh screens and potentially faster-acting internals, to better resist clogging from small oil debris and sludge, which is the primary failure mode noted in Ford's TSBs.
  Heads up: The parts are physically interchangeable, but it is highly recommended to use the latest HL3Z-6M280-A revision for improved durability.

Model Year Variations Within This Range

• 2020-2021: There are no significant documented changes to the 3.5L V6 VCT system, solenoids, or phasers between the 2020 and 2021 model years for the Ford Transit that would alter the diagnosis or common causes of code P0025.