B2278 BMW Fault Code
Check B2278 OBD Fault Code ReasonOutput 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.
B2278 Code Symptoms :
The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. B2278 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 B2278
B2278 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 B2278 code ?
- EVAP system hose leaking
- Engine Control Module (ECM)
- Faulty TCM or TCM programming
- Loss of ground.
Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code B2278, so consult the manual to locate the brake fluid reservoir.
Bear in mind that a low fluid level can set code B2278 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.
