135B11

What Code 135B11 Means

Code 135B11 belongs to the Valvetronic system and points to a problem with the Valvetronic servomotor. The fault is similar in nature to 135808. It can be caused by a mechanical problem in the Valvetronic drive or by a servomotor calibration error.

Valvetronic regulates intake valve lift, changing valve stroke instead of using a conventional throttle plate. The Valvetronic servomotor works through a worm gear and an eccentric shaft to change the position of the intermediate lever, which in turn sets valve lift. The DME monitors servomotor position and compares it with the calculated value; if the two don't match, the position falls outside the allowed range, or calibration can't be completed, code 135B11 is stored.

The affected system includes the Valvetronic servomotor, worm gear, eccentric shaft, intermediate levers, eccentric shaft position sensor, and the engine control unit (DME).

Symptoms

• Unstable engine operation.
• Error messages appearing on the instrument cluster.

Diagnosis and Repair

1. Run a Valvetronic system diagnostic with ISTA or INPA: read the fault codes, check actual servomotor and eccentric shaft position values, and run the actuator test.
2. Inspect the Valvetronic mechanism: check the worm gear, eccentric shaft, intermediate levers, and servomotor for mechanical damage, binding, and wear.
3. Replace the faulty components if needed.

Related Issues

The source data notes rear bumper damage that is unrelated to code 135B11:

• a hole below the left sensor; sensor function has not been tested yet;
• damage to the upper bumper edge directly under the trunk lid edge;
• light scuff marks on the trunk lid.