C0340 BMW Fault Code

Description:

BMW HO2S Sensor Circuit Malfunction (HO2S-11) During testing the HO2S Heaters are checked for opens/shorts and excessive current draw.
The BMW test fails when current draw exceeds a calibrated limit and/or an open or short is detected. Short to VPWR in harness or HO2S. Water in harness connector. Open VPWR circuit. Open GND circuit. Low battery voltage. Corrosion or poor mating terminals and wiring Damaged HO2S heater. Damaged PCM.

C0340 Code Symptoms :

The original multi-displacement system turned off opposite pairs of cylinders, allowing the engine to have three different configurations and displacements. C0340 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 C0340

C0340 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 C0340 code ?

• Damaged camshaft position (CMP) sensor
• Faulty spark plug (s)
• Camshaft advance mechanism binding (VCT unit)
• Oil flow restriction in the oil passages or the variable camshaft timing (VCT) valve body

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code C0340, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code C0340 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.