2104 is a relatively rare OBD-II trouble code. It indicates that your Audi A4’s PCM has disabled the gas pedal, leaving the engine stuck at idle. It’s a generic code, so it has the same definition no matter what type of vehicle has the code. P2104 Definition: Throttle Actuator Control System – Forced Idle There … Read more
P2101 is a general OBD2 trouble code. It has the same meaning for the Audi A4 as it would any other vehicle. It is typically caused by wiring issues at the throttle actuator, or a bad throttle actuator itself. P2101 Definition: Throttle Actuator “A” Control Motor – Circuit Range/Performance Throttle Actuator “A” Control Motor Circuit … Read more
P2106 is a somewhat uncommon OBD-II code. It is not manufacturer-specific, so it has the same meaning for your Audi A4 as it would any other vehicle. It is an indication that limp mode/failsafe mode has been activated. There is a myriad of problems that can cause P2106. The throttle actuator itself is rarely the … Read more
Modern vehicles use knock sensors to detect engine detonation. This allows the PCM (powertrain control module) to run very aggressive spark timing. If you are concerned that your Audi A4 has a bad knock sensor, we’ve listed them out below. A knock sensor works by listening to your engine and determining if your A4 is … Read more
No matter where you live if your Audi A4’s AC compressor is not turning on, it can turn a pleasant commute into a nightmare (particularly if you have kids that are riding with you). The AC compressor pulley is always being turned by either the serpentine belt or a dedicated belt (it’s going to depend … Read more
U0101 is a generic powertrain code, which means it has the same definition for the Audi A4 as it would any other vehicle. It means that your A4’s TCM (Transmission Control Module) can’t communicate with the rest of the vehicle, usually due to a bad wiring harness or an issue with the TCM itself. U0101 … Read more
P219B is a generic OBD2 trouble code. This code indicates that your Audi A4’s air/fuel ratio is out of balance (too rich or too lean) on the bank 2 side of the engine in question. Your A4 is equipped with oxygen sensors that measure the air-fuel ratio of your engine. It’s these sensors that are … Read more
P219A is a generic OBDII code. The code indicates that your Audi A4’s air/fuel ratio is out of balance (too rich or too lean). Your A4 is equipped with oxygen sensors that measure the air-fuel ratio of your engine. It’s these sensors that are reporting the problem with the air-fuel ratio. With P219A are … Read more
U0100 is a generic diagnostic trouble code, meaning it has the same definition for any vehicle made in the 1996 model year or newer (including the Audi A4). This code tells you that communication has been lost between the ECM/PCM (main computer) and a particular control module has been completely lost. When a vehicle has … Read more
P2099 is a generic OBD II code. It has the same meaning for the Audi A4 as it would any other vehicle. It specifically indicates that your A4 detected that air-fuel mixture reading as the exhaust gas exits the catalytic converter on the bank 2 side of the engine is too rich. (too much fuel … Read more