27B5

What the Code Means

Code 27B5 points to a fault in intake VANOS control. The DME detected an error in the control circuit for the VANOS solenoid on the intake camshaft.

Normally the DME controls intake camshaft timing through this solenoid, varying oil flow to the VANOS unit. If the control circuit has an open, a short, or the solenoid itself fails mechanically, the DME can no longer set cam timing correctly. The cause can be a failed solenoid, damaged wiring, or a failed control module.

Symptoms

• Power loss at low rpm;
• rough idle;
• increased fuel consumption;
• Check Engine light on.

Diagnosis and Repair

1. Check the VANOS solenoid wiring and connectors — corroded contacts and damaged insulation are a common cause of a control circuit fault.
2. Measure the solenoid winding resistance: 7–12 ohms is the normal range. A value outside that range points to a failed solenoid.
3. Replace the VANOS solenoid with a new one — OEM part number 11367579070.
4. After the repair, reset the DME adaptations with ISTA so the module relearns cam timing.

A common diagnostic mistake is replacing the solenoid without checking the wiring and connectors: if the circuit is the problem, a new solenoid won't fix it.

Secondary Problems

• The timing chain can jump, which will cause valve-to-piston contact and an engine rebuild;
• catalytic converter failure from incomplete combustion.