P0029 — Exhaust Valve Control Solenoid Circuit Bank 2 Range/Performance #

Note: The description for code P0029 may vary depending on the vehicle manufacturer.

• P0029: Exhaust Valve Control Solenoid Circuit Range/Performance (BMW, Ford, Nissan, Toyota, GM, etc.)
• P0029: Variable Valve Timing (VVT) Solenoid Malfunction – Exhaust Bank 2 (Mercedes-Benz)
• P0029: Exhaust Camshaft Position Actuator Circuit Performance Bank 2 (Chevrolet, GMC)

Summary of code P0029 #

DTC P0029 is an OBD-II diagnostic trouble code that indicates an issue with the exhaust valve control solenoid circuit on Bank 2 of the engine. This circuit is responsible for managing the timing of the exhaust valves using a device called a Variable Valve Timing (VVT) solenoid. When the Powertrain Control Module (PCM) detects a performance problem or range issue – meaning the circuit is not operating within manufacturer-specified parameters – it triggers this code. This can result in suboptimal engine performance and increased emissions. Addressing this issue promptly is important to avoid further complications.

Common symptoms for code P0029 #

If your vehicle has triggered code P0029, you might notice various symptoms that can range from subtle to more pronounced. The engine may not run as smoothly as usual, and you might experience a decrease in performance or fuel efficiency. In some cases, the check engine light is the only obvious warning. Here are the most frequent signs:

• Check Engine Light illuminated on the dashboard
• Rough idle or unstable engine RPM
• Noticeable drop in engine power or hesitation during acceleration
• Reduced fuel economy
• Possible increased exhaust emissions
• In rare cases, engine stalling or hard starting

Probable causes for code P0029 (by frequency) #

The root cause of P0029 most often involves an electrical or mechanical fault within the exhaust valve control solenoid circuit. However, several other factors can contribute to this DTC. Here is a ranked list, starting with the most common causes:

1. Faulty exhaust VVT solenoid (bank 2) – the solenoid itself is defective or stuck
2. Wiring issues – damaged, chafed, or corroded wires/connectors in the solenoid circuit
3. Oil flow problems – dirty or low engine oil, which can block VVT operation
4. PCM/ECM malfunction – rare, but the engine computer may have an internal fault
5. Mechanical timing issues – worn camshaft actuators or timing chain/belt problems

Step-by-step diagnosis for code P0029 #

Diagnosing the P0029 code requires a systematic approach to pinpoint the exact cause. Here’s a step-by-step checklist for technicians and advanced DIYers:

• Verify the code with a professional-grade OBD-II scanner and note any related codes.
• Inspect engine oil level and quality; top up or change if needed.
• Visually check wiring and connectors at the exhaust VVT solenoid on bank 2 for damage or corrosion.
• Test the VVT solenoid (bank 2) for proper resistance and operation using a multimeter as per OEM specifications.
• Check for oil sludge or blockage in the solenoid’s oil passages.
• Command the solenoid on/off using a scan tool to verify function.
• If all else checks out, evaluate camshaft actuator operation and timing chain/belt condition.
• As a last resort, test the PCM/ECM for internal faults or reflash if a software update is available from the OEM.

Possible repairs for code P0029 #

The appropriate repair for P0029 depends on the root cause identified during diagnosis. Addressing the underlying issue will restore proper exhaust valve timing function and prevent further engine or emissions problems. Here are the most common fixes:

• Replace the faulty exhaust VVT solenoid on bank 2
• Repair or replace damaged wiring/connectors in the solenoid circuit
• Change engine oil and filter to ensure proper VVT operation (use the grade and specification recommended by the OEM)
• Clear oil passages to the solenoid if sludge or debris is found
• Correct mechanical timing issues (timing chain, cam phaser, or actuator replacement if worn)
• Update or reprogram PCM/ECM if a software issue is confirmed

Is it safe to drive with code P0029? #

Limited: While the vehicle may still be drivable with P0029 present, it is not advisable to ignore this code. The engine may experience reduced performance, increased emissions, and, in rare cases, further mechanical damage if the underlying issue is not addressed. If you notice symptoms like rough running, stalling, or significant power loss, limit driving and arrange for diagnosis and repair as soon as possible.

Vehicles most commonly affected by code P0029 #

While P0029 can occur across a wide range of modern vehicles equipped with variable valve timing, it is most frequently reported on models from manufacturers that use advanced VVT systems. These include:

• BMW 3-Series, 5-Series, X3, X5 (especially with N52, N54, N55 engines)
• Mercedes-Benz C-Class, E-Class, GLK, ML (with V6/V8 engines)
• Chevrolet Malibu, Equinox, Traverse, Silverado (with V6 engines)
• Ford F-150, Mustang, Edge (with DOHC engines)
• Nissan Altima, Maxima, Murano (VQ-series engines)
• Toyota Camry, Avalon, Highlander (V6 engines with VVT-i)

Common mistakes & best practices with code P0029 #

Misdiagnosis of P0029 is not uncommon, often due to skipping basic checks or replacing parts unnecessarily. To avoid wasted time and money, follow these best practices:

• Don’t replace the VVT solenoid before checking oil condition and level – oil issues are a frequent root cause.
• Always inspect wiring/connectors for visible faults before replacing expensive components.
• Use OEM or high-quality parts for replacements to ensure reliability.
• Test components before replacing – bench test the solenoid if possible.
• Clear codes and perform a road test after repairs to verify resolution.

Quick FAQ for code P0029 #

Still have questions? Here are quick answers to the most common concerns:

• Q: Can I reset code P0029 with a scanner and keep driving?
  A: You can clear the code, but if the underlying issue is not fixed, the code and symptoms will return. Always diagnose and repair the root cause.
• Q: Is a bad VVT solenoid expensive to replace?
  A: On most models, replacement parts are moderately priced, but labor costs vary. Wiring or timing issues may increase repair time and cost.