P0029: Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2
May cause reduced engine performance, rough idle, decreased fuel economy, and increased emissions
Overview
P0029 is a generic OBD-II code indicating that the exhaust valve control solenoid circuit on engine bank 2 is operating outside of the expected range or performance parameters, often linked to VVT system issues
Common Symptoms
- Check Engine Light (MIL) illumination
- Rough or unstable idle
- Reduced engine power or hesitation
- Increased fuel consumption
Most Common Causes
Solenoid failure or internal binding can cause circuit performance errors
Dirty oil or incorrect viscosity can impede hydraulic control of VVT system
Circuit interruptions can mimic solenoid faults
Mechanical failure in the actuator system can reflect as solenoid circuit out-of-range
Rare but possible misinterpretation of solenoid performance due to control module issues
Diagnostic Steps
-
Verify DTC P0029 using a professional OBD-II scanner and note any related codesExpected: P0029 stored in ECM with or without related VVT codesInterpretation: Confirms initial detection and checks for additional context
-
Check engine oil level and condition; change oil if low or contaminatedExpected: Oil within manufacturer spec and cleanInterpretation: Ensures proper hydraulic control for VVT operation
-
Visually inspect wiring and connectors to exhaust VVT solenoid on bank 2Expected: No open, shorted, or corroded connectionsInterpretation: Rules out electrical faults in control circuit
-
Test solenoid electrical resistance and activation with multimeter/scan toolExpected: Solenoid resistance within OEM spec and proper actuation when commandedInterpretation: Validates solenoid functionality
-
If solenoid tests good, assess camshaft actuator operation and timing componentsExpected: Actuator moves freely and timing components intactInterpretation: Checks mechanical integrity of VVT system
-
Evaluate ECM/PCM for software updates or internal faultsExpected: No firmware or control module errorsInterpretation: Eliminates control unit issues
Repair Solutions
Often resolves issues caused by oil contamination or low pressure
Typical repair when solenoid tests out of spec
Depends on wiring harness accessibility and damage extent
Requires deeper engine work; costs vary widely
Rare; ensure diagnostics confirm module issue
Common Misdiagnoses
Avoid these common diagnostic mistakes:
- Replacing the solenoid without checking engine oil condition or wiring integrity
User Comments (0)
Share your experience or ask a question about this code.
Please login to post a comment.
Be the first to share your experience with P0029!