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C129E BMW Fault Code

Check C129E OBD Fault Code Reason
Description:

Output Shaft Speed sensor circuit intermittent failure The output shaft speed sensor signal to the PCM is irregular or interrupted.
Harness connector not properly seated Harness intermittently shorted, or open Harness connector damaged OSS sensor damaged, or not installed properly Verify harness and connector integrity Verify OSS sensor proper installation.

C129E Code Symptoms :

See C129E in engine

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. C129E code had an elaborate diagnostics procedure, including showing engine trouble codes on the air conditionning display. However, the system was troublesome, misunderstood by customers, and a rash of unpredictable failures led to the technology being quickly retired.

Diagnosis And Repairing C129E

C129E OBD 2 code on vehicles with electronically controlled automatic transmissions, the 3-4 shift solenoid is responsible for actuating the hydraulic circuits to activate clutches or bands that change gears inside the automatic transmission.

How to fix C129E code ?

See C129E repair manual
  • EVAP system hose leaking
  • Camshaft advance mechanism binding (VCT unit)
  • Ignition misfiring
  • Dirty Oil

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code C129E, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code C129E on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.

BMW Cars that meet C129E error