VAG Error Code: 16505/5286/000289
EOBD II Error Code: P0121

Fault Location:
Throttle Position Sensor (G69) - Implausible Signal

Possible Cause:
Malfunction Indicator Lamp (MIL)(K83) active.
Poor engine performance.

Accelerator cable adjustment.
Throttle position sensor (G69).
Wiring/Connector(s)/Wiring Harness issue.
Failed Throttle Body.
Failed Engine Control Module (ECM).
Check for water ingress.

Possible Solutions:
Check/Replace all faulty Wiring/Connector(s).
Read Measuring Value Blocks (MVB).
Throttle Position Sensor 1 - Throttle Position Sensor 2 > 6.30%.
Actual Throttle Position Sensor 1 calculated value > Throttle Position Sensor 2 calculated value.
Throttle Position Sensor 1 calculated value > 9.00%.
Test wiring as per Factory Repair Manual

Special Notes:
For some vehicles, there may be a Technical Product Information (TPI) with instructions on replacing the terminals for the throttle body.
Some Engine Control Module (ECM)s may have a firmware update to address this issue during cold weather.
The component identifier Throttle Position Sensor (G69) may be Angle Sensor 1 for Throttle Actuator (G187) per the wiring diagrams for the vehicle in question.

When is the code detected?:
Malfunction is detected when an excessively low or high voltage from the sensor is sent to Engine Control Module (ECM).

Description:
The throttle position sensor responds to the accelerator pedal movement. This sensor is a kind of potentiometer which transforms the throttle position into output voltage, and emits the voltage signal to the Engine Control Module (ECM). In addition, the sensor detects the opening and closing speed of the throttle valve and feeds the voltage signal to the Engine Control Module (ECM).

Idle position of the throttle valve is determined by the Engine Control Module (ECM) receiving the signal from the throttle position sensor. This sensor controls engine operation such as fuel cut. On the other hand, the Wide open and closed throttle position switch, which is built into the throttle position sensor unit, is not used for engine control.