Fault Code Lookup › Powertrain codes › P0021
P0021 Powertrain · generic OBD-II
'A' Camshaft Position - Timing Over-Advanced or System Performance
P0021 is a standard code covering engine, transmission, fuel and emissions. It names the system that logged the fault, not the part that failed. Below: which cars owners reported it on, what happened, and recalls on those cars, from 12 complaints filed with NHTSA. Updated November 3, 2026.
Owners also write it as P002177 (the last two characters are the sub-code).
- 12owner reports
- 9car models
- 0mention a crash
- 0mention a fire
- 2013–2022model years
Which cars get code P0021?
Every model whose owners mentioned P0021 in a complaint, most reports first. Each year opens that car's full problem report. Popular models collect more reports because more of them are on the road.
Ford F-150
2 reportsChevrolet Blazer
1 reportFord Expedition
1 reportFord Expedition EL
1 reportGMC Acadia
1 reportGMC Canyon
1 reportGMC Savana
1 reportMercedes-Benz E-Class
1 reportWhere does P0021 show up?
By brand
- Chevrolet4
- Ford4
- GMC3
- Mercedes-Benz1
Component the owner filed it under
Is there a recall for P0021?
The others concern the component owners file this code under (Engine) on the same cars; they may or may not relate to the code. Recall repairs are free; check your VIN at nhtsa.gov/recalls.
Engine Ford Motor Company (Ford) is recalling certain 2015-2019 Ford F-150 and 2017-2019 Ford F-250 Super Duty, F-350 Super Duty, F-450 Super Duty, and F-550 Super Duty pick-up trucks equipped with an engine block heater and previously remedied under recall 18V894. During the previous repair, the block…
2019 Ford F-150. Full risk and remedy on each car's report.
Engine Ford Motor Company (Ford) is recalling certain 2015-2019 Ford F-150 and 2017-2019 Ford F-250 Super Duty, F-350 Super Duty, F-450 Super Duty, and F-550 Super Duty pick-up trucks equipped with an engine block heater. Water and contaminants may get into the block heater cable's splice connector causing…
2019 Ford F-150. Full risk and remedy on each car's report.
What happened when owners saw P0021?
10 of the 12 reports, spread across the models above, as the owners wrote them. NHTSA removes names and VINs; long reports are trimmed. CarHooq has not verified individual claims.
DRIVING LATE AT NIGHT WITH FAMILY DOWN A STATE HIGHWAY/CITY STREET WITH SOME STOPLIGHTS AND ROTARY, VEHICLE SUDDENLY SEEMS TO BE INTERMITTENTLY LOSING POWER OR TRANSMISSION SLIPPING WHEN DRIVING. WHEN GIVING GAS ENTERING ROTARY, INTERMITTENT SLIPPING/POWER LOSS (LIKE A SKIPPING POWER/SLIPPING TRANSMISSION) WORSENED - FELT GREATER LOSS OF POWER AND FOR SLIGHTLY LONGER PERIODS. NOTED ENGINE LIGHT CAME ON. WORSENING INTERMITTENT POWER FAILURE/SLIPPING/HESITATION/JERKING CONTINUED WHEN GIVING GAS TO ENGINE FOR ~1/4 MILE UNTIL PULLED INTO SHOPPING MALL PARKING LOT. FELT LUCKY TO BE ABLE TO REACH LOT, CALLED FOR FLATBED TOW TO DEALER. DEALER HAD VEHICLE FOR 1 WEEK, AND WHEN ASSESSMENT COMPLETE…
The vehicle has given codes P0018 and P0021 on multiple occasions. These codes are likely due to an issue with the cam phasers. This is a known issue due to a design flaw.
Received Error code P0021 "A" camshaft position timing is over-advanced in Bank 2 of the engine" Occured 3 times before taking it into dealer. Chevrolet dealership agreed and it was covered under powertrain warranty.
My family received a notice of Customer Satisfaction Program 21N08 – PCM Reprogram Due to Engine Shudder – 2017-2020 Ford F-150, 2018-2020 Expedition, & 2018-2020 Lincoln Navigator. We immediate began trying to locate an authorized repair facility. It took several months to get an appointment. During this time, our vehicle shuddered, stopped, and even turned off completely while driving. The problem continued to increase in intensity. When we were able to get the vehicle into a Ford dealership, they suggested that we contact Ford for the repairs that we needed. A private repair facility told us that now, because the shudder issue was not resolved right away, they discovered VCT phasers, VCT…
My family received a notice of Customer Satisfaction Program 21N08 – PCM Reprogram Due to Engine Shudder – 2017-2020 Ford F-150, 2018-2020 Expedition, & 2018-2020 Lincoln Navigator. We immediate began trying to locate an authorized repair facility. It took several months to get an appointment. During this time, our vehicle shuddered, stopped, and even turned off completely while driving. The problem continued to increase in intensity. When we were able to get the vehicle into a Ford dealership, they suggested that we contact Ford for the repairs that we needed. A private repair facility told us that now, because the shudder issue was not resolved right away, they discovered VCT phasers, VCT…
TL* THE CONTACT OWNS A 2014 GMC ACADIA. THE CONTACT STATED THAT THE CHECK ENGINE WARNING LIGHT WAS ILLUMINATED. THE CONTACT TOOK THE VEHICLE TO JIM CURLEY BUICK GMC OF KEYPORT (400 NJ-35, KEYPORT, NJ 07735) TO HAVE A DIAGNOSTIC TEST PERFORMED. THE TECHNICIAN RETRIEVED FAILURE CODES: P0018 AND P0021 SHOWING THAT THE TIMING CHAIN AND CAMSHAFT ACTUATOR WERE NO LONGER PERFORMING PROPERLY. THE CONTACT WAS INFORMED THAT THE TIMING CHAIN NEEDED TO BE REPLACED. THE CONTACT ALSO WANTED TO STATE THAT THE VEHICLE WAS TAKEN TO SAME DEALER SEVERAL TIMES FOR THE ENGINE LIGHT BEING ILLUMINATED HOWEVER, THE DEALER CLEARED THE ENGINE CODES UNDER THE VEHICLE WARRANTY. THE VEHICLE WAS NOT REPAIRED. THE…
I have been dealing with a sweet/Christmas-like smell in my car occasionally for the last several months. This is a health & safety concern for me involving ethylene glycol fumes in the cabin. These fumes could be linked to why I have experienced increased sinus headaches over the past several month. I took it into CarMax (where I purchased the vehicle) and they were able to diagnose the issue and state that my heater core needed to be replaced. However, since my vehicle was under 36,000 miles, it needed to go to the dealer. The dealer that has been working on the vehicle is Hendrick Hoover Chevrolet. I have taken the vehicle to the dealer twice already and they have not been able to…
I have been dealing with a sweet/Christmas-like smell in my car occasionally for the last several months. This is a health & safety concern for me involving ethylene glycol fumes in the cabin. These fumes could be linked to why I have experienced increased sinus headaches over the past several month. I took it into CarMax (where I purchased the vehicle) and they were able to diagnose the issue and state that my heater core needed to be replaced. However, since my vehicle was under 36,000 miles, it needed to go to the dealer. The dealer that has been working on the vehicle is Hendrick Hoover Chevrolet. I have taken the vehicle to the dealer twice already and they have not been able to…
Component/System: The intake camshaft positioner/adjuster on cylinder bank 2 of the M276 V6 engine has failed, along with associated timing components. The vehicle (2018 Mercedes-Benz E400, VIN [XXX]) remains unrepaired and is available for inspection upon request. Safety Risk: The engine produces a loud metallic rattle on cold starts, indicating loss of proper camshaft timing control. If unaddressed, camshaft timing deviation can progress to timing chain failure, which on interference engines can cause valve-to-piston contact and sudden, severe engine damage or loss of power while driving, posing a risk to vehicle control. Confirmed by Dealer: Yes. Mercedes-Benz of Catonsville (RO# [XXX])…
IN EARLY APRIL 2019, APPROXIMATELY THE FIRST WEEK OF APRIL, I WAS DRIVING THE TRAVERSE ON A HILL AND STOPPED AT A STOP LIGHT. WHEN THE LIGHT TURNED GREEN, I ATTEMPTED TO STEP ON THE GAS AND PULL FORWARD, BUT THE CAR ROLLED BACKWARDS. I LOOKED DOWN TO SEE IF I WAS IN REVERSE, BUT THE CAR WAS IN DRIVE. THIS SPECIFIC INCIDENT OCCURRED A TOTAL OF TWO TIMES. ON APRIL 23, 2019 AROUND 9:40 AM I WAS DRIVING AND MY CAR STALLED MULTIPLE TIMES DURING THIS TRIP. I WAS NOT SURE IF THE CAR WAS GOING TO MAKE IT TO MY FINAL DESTINATION. THE CHECK ENGINE LIGHT ILLUMINATED. ON APRIL 24, I RECEIVED A CALL FROM THE DEALERSHIP. THE DEALERSHIP INFORMED ME THAT THE CAR SHOWED 4 'CODES'. P0011 'A' CAMSHAFT POSITION…
P0021: questions drivers ask
What does code P0021 mean?
P0021 is a generic OBD-II powertrain code. Its standard definition is "'A' Camshaft Position - Timing Over-Advanced or System Performance". The code tells you which system set the fault, not which part failed; the owner reports on this page show what it meant in practice for 9 car models.
Which cars get code P0021 most often?
In NHTSA owner complaints, P0021 is mentioned most for the Chevrolet Traverse (3), Ford F-150 (2), Chevrolet Blazer (1), across 9 models and model years 2013 to 2022. Popular models collect more reports because more of them are on the road.
Is there a recall for code P0021?
No NHTSA recall text names P0021 directly. 2 recalls on the cars that report this code concern the same component owners name most (Engine); they may or may not relate to the code. Check your VIN at nhtsa.gov/recalls.
What should I do if my car shows P0021?
Write down when the code appeared and what the car did (warning lights, loss of power, noises, speed, weather). Check your VIN for open recalls at nhtsa.gov/recalls, ask a dealer or independent workshop to read the stored freeze-frame data before anyone clears the code, and keep the repair order. If the car loses power in traffic, stop driving it. CarHooq does not diagnose: these are owner reports and official recall notices, not repair advice.
How this page was made
CarHooq read the text of every owner complaint filed with NHTSA for 19 US and European brands (model years 2012 onwards) and picked out the diagnostic trouble codes owners wrote down. This page lists every mention of P0021 (including sub-code forms such as P002177). The definition is the generic SAE J2012 wording; a carmaker may use the code slightly differently. Nothing here is a diagnosis. Data: NHTSA Office of Defects Investigation (public domain), retrieved November 3, 2026. How CarHooq reports are made.
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