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2012 Ford Traverse P0021 and P0024 Fault: Variable Valve Timing Issues After Timing Chain Replacement

Model: 2012 Traverse Fault Code: P0021 Posted: 2017-11-29 08:56

I recently had the timing chain and gears replaced on my 2012 Ford Traverse. Since the replacement, I've been experiencing DTC codes P0021 and P0024, both related to variable valve timing (VVT) systems. The repair shop confirmed that all components—including camshaft phasers—were replaced with new parts. However, the fault codes persist. I'm now wondering if there's a proper ECU reset procedure available for these codes, or whether I'll need another engine removal to inspect the issue further. Any insights on troubleshooting this specific problem would be greatly appreciated.

Related fault codes
P0021P0024
Comments (4)
Anonymous 2017-11-29 09:38

Are there any additional diagnostic trouble codes (DTCs) present? DTC P0021: Intake Camshaft Position System Performance - Bank 2 DTC P0024: Exhaust Camshaft Position System Performance - Bank 2 Note on engine oil—check pressure, quality, and quantity. Did you verify the bank 2 VCT solenoid circuits? Ensure proper 12V power supply, continuity from solenoid to PCM, and resistance within specification (5–12 Ω). During idle conditions, observe camshaft position variance. Command the camshaft actuator from 0° to 20° and back to 0° using a scan tool, monitoring the camshaft position variance parameter. The variation should remain below 2° in both commanded states.

Anonymous 2017-11-29 10:29

Since the timing chain was replaced twice by a certified shop in my area, I suspect they may have used clean oil with correct viscosity and properly reconnected all components. However, this issue arose due to an overdue oil change. The oil appeared clean when inspected yesterday. After clearing the codes, the fault returned within 20 minutes of driving. Given that camshaft positioning relies on oil pressure from the phaser, load conditions may be influencing system performance.

Anonymous 2017-11-29 11:30

"Those cam positions react off of oil pressure sent from the phaser right? Due to load." Yes—though with some technical nuance: the camshaft position is adjusted using oil pressure, which is commanded by the PCM via a solenoid that supplies pressure to the actuator. It appears your system is not responding as commanded, and only Bank 2 is showing issues. Did the shop replace all four phaser actuators? A diagnostic scan tool can analyze crank-to-cam timing correlation and check for 'park' offset versus commanded offset values.

Anonymous 2017-11-29 12:22

Yes, the shop confirmed that all four camshaft phasers were replaced during the service.