P0021 on Chevrolet: How to Diagnose & Fix
Intake Camshaft Position Timing - Over-Advanced (Bank 2)
1 Chevrolet model · 1 documented issue · $150-$900 repair
P0021 on Chevrolet by model: symptoms, diagnosis and fix
The second-generation 3.6L LFY runs four cam phasers fed by oil-control solenoids. On early C1XX Traverse builds the solenoids stick or screen-clog with casting/machining debris and varnish, and the ECM calibration was itself part of the problem. The result is a set of correlated cam timing codes — commonly P0011 with P0014, P0021 and P0024 appearing together — plus a rough idle, a rattle on start-up as the phasers fail to lock, and reduced power. GM addressed the calibration side with bulletin N192266190 (ECM reprogram). This is distinct from the LLT/LFX timing chain stretch problem: the chains here are not necessarily worn, the phaser control is.
Common Symptoms
- Check engine light
- Rough or unstable idle
- Rattle on cold start-up
- Reduced engine power
- Hesitation on acceleration
How to Fix
Start with a known-good oil and filter service using dexos1 5W-30 full synthetic — degraded or overfilled oil alone will set these codes on this engine. Then check with a dealer whether ECM calibration bulletin N192266190 is open for the VIN; the reprogram resolves a meaningful share of cases at no parts cost. If codes persist after the reflash, test the cam actuator solenoids for correct resistance and replace the affected solenoid(s) and screens; heavily varnished engines may need the phasers themselves. Only after solenoid and oiling causes are excluded should chain stretch be suspected — and verify it with an actual cam/crank correlation measurement, not an assumption.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Camshaft position actuator (VVT) solenoid valve — 3.6L LFY (one part number serves all four intake/exhaust positions; reOEM12636175Cross-refDorman 917-219, SKP SK917219, Gates VVS (see RockAuto/eBay Gates listing for Traverse 3.6L$35–$60
GM 12636175 is the long-running 3.6L HFV6 cam-phaser oil-control solenoid and remains the catalogued number for the 2018-2020 (and later) Traverse 3.6L LFY; GM catalog listings span 2004-2025. Sold individually — the LFY uses four (2 int…
- Engine oil filter — 3.6L LFY (for the dexos1 5W-30 full-synthetic oil and filter service that is step one of the fix)OEM12731742Cross-refACDelco PF63E (GM 12690385), ACDelco PF63 (GM 12707246 / 89017525), GM 12690385 (superseded to 12731742)$6–$15
The 2018-2019 Traverse 2.0T uses a different filter (19417843/25206377/12699847) — do not cross.
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Sources for this issue (2)
P0021 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0021 mean on a Chevrolet?
P0021 stands for "Intake Camshaft Position Timing - Over-Advanced (Bank 2)." P0021 means the engine computer detected that the intake camshaft on bank 2 is timed too far advanced and won't return to its commanded position. Most modern engines use variable valve timing (VVT), where an oil-pressure-driven actuator rotates the camshaft to optimize power and efficiency; the PCM compares the camshaft's actual position to its target. When the cam stays over-advanced beyond an acceptable limit, this code sets. Bank 2 refers to the side of the engine that does not contain cylinder number one. You may notice rough idle, reduced performance, or lower fuel economy. On Chevrolet it is documented across 1 model: Traverse.
What are the most common causes of P0021?
The most common causes of P0021 are: Dirty or low engine oil restricting the VVT system, Stuck or failed camshaft oil control valve (VVT solenoid) on bank 2, Clogged VVT solenoid screen or oil passage, Faulty camshaft position actuator / phaser, Wiring or connector fault at the VVT solenoid, Camshaft or crankshaft position sensor problems, Worn timing chain, guides, or stretched chain altering cam timing. The specific cause varies by vehicle.
How much does it cost to fix P0021 on a Chevrolet?
Published repair estimates on Chevrolet range from $150 to $900 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0021 on a different make?
View P0021 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.