B1146 BMW Fault Code

Description:

Catalytic converters must be warm before they can work properly. On a cold start the PCM provides a rich mixture to keep the cold engine running.
All that extra fuel goes into the catalytic converter. But the exhaust isn't very hot, because, ah, the engine is pretty cold. GM has employed several strategies to fire up the catalytic converter quicker and reduce cold start emissions. One way is to use a secondary air pump that pumps outside air directly into the catalytic converter.

B1146 Code Symptoms :

If your B1146 check engine light is illuminated, it's best to take it in for diagnostic testing, which can feel like a hassle. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system. The on-board diagnostics system B1146 and engine control unit are in charge of monitoring a bunch of different , and if they get a reading that's a little out of whack, up pops the check engine light.

Diagnosis And Repairing B1146

B1146 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 B1146 code ?

• Air fuel ratio (A/F) Sensor 1 Bank 1 harness is open or shorted
• Damaged ECM
• Damaged camshaft position (CMP) sensor
• Oil flow restriction in the oil passages or the 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 B1146, so consult the manual to locate the brake fluid reservoir.

Bear in mind that a low fluid level can set code B1146 on some applications, so make sure that on fluid operated systems the fluid level is up to the mark before starting an electrical diagnosis.