B1031 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.

B1031 Code Symptoms :

OBD B1031 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and B1031, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to malfunction without leading to an immediate increase in emissions at the tailpipe.

In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

Diagnosis And Repairing B1031

B1031 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 B1031 code ?

• Damaged camshaft position (CMP) sensor
• EVAP system hose leaking
• Fuel filler cap remains open or fails to close
• Ignition coils circuit poor electrical connection

Some systems require that the actuator has an adequate supply of brake fluid. Low brake fluid levels can mimic the symptoms of code B1031, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code B1031 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.