P0029 trouble code definition

Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 2)

What the P0029 code means

P0029 is the OBD-II generic code indicating the engine control module (ECM) has determined that the variable valve lift solenoid for the exhaust valves for bank 2 takes too long to engage or does not engage.

What causes the P0029 code?

  • The ECM activates the exhaust valve solenoid for bank 2 and the valve lift does not shift.

  • The exhaust variable valve lift solenoid is short circuited internally.

  • The variable valve lift solenoid has an open circuit internally.

  • The wiring or connections to the exhaust valve solenoid or the ECM is shorted or open.

What are the symptoms of the P0029 code?

  • The engine can lack power if the valve lift fails in the low position.
  • The engine may run rough or stall.
  • The engine will run very erratic at idle and on acceleration.
  • The check engine will be illuminated indicating a problem.

How does a mechanic diagnose the P0029 code?

  • Visually check the electrical connections and wire harness to the bank 2 exhaust valve solenoid.

  • Clear codes and verify if the code returns.

  • Utilize the test solenoid to operate the variable valve lift is operational mechanically.

  • Test the lift solenoid for internal short or open circuit to solenoid specifications.

  • Follow the manufacturer's specific pinpoint tests for further diagnosis.

Common mistakes when diagnosing the P0029 code?

Follow these simple guidelines to prevent mistakes:

  • Verify the failure by clearing the code and seeing it the problem is still present.

  • Do not attempt any diagnosis without special tools like a test solenoid.

  • Follow any pinpoint test, step by step, to isolate the failure on the system.

  • Do not replace any parts unless directed by the pinpoint or visual testing.

How serious is the P0029 code?

  • The engine can hesitate and have a lack of power during acceleration.

  • The engine may start real hard or run too lean.

  • The engine may stall when stopping or run rough.

What repairs can fix the P0029 code?

  • Clearing the fault codes and performing a road test to try and verify the failure

  • Replacing the variable valve lift solenoid for the exhaust camshaft bank 2

  • Repairing or replacing the wiring or connection to the exhaust lift solenoid

  • Repairing the ECM connector or replacing the ECM

Additional comments for consideration regarding the P0029 code

The variable valve lift solenoid can get clogged with sludge or thick oil, and not actuate the variable valve lift mechanism. The oil needs to be kept clean and of the proper viscosity.

Need help with a P0029 code?

YourMechanic offers certified mobile mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

This article originally appeared on YourMechanic.com as P0029 OBD-II Trouble Code: Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 2) and was authored by Jay Safford.


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