P1123 FORD, LINCOLN, MERCURY: INTERMITTENT HIGH VOLTAGE IN THROTTLE POSITION SENSOR CIRCUIT
POST UPDATED IN June, 2023
P1123 Code failures by brands
Description of DTC code P1123
For the engine to run smoothly, the air/fuel mixture must be kept within optimum levels. The amount of air in the engine is controlled by the air intake system. The throttle body is installed in this system, which assists in controlling the air entering the engine.
The throttle body has a plate, which when closed prevents air from entering the engine. By the time the accelerator pedal is depressed, the plate opens allowing air to enter the engine, the amount of which depends on the position of the plate, which is controlled by the pedal. The harder the pedal is pressed, the more the throttle body opens, which translates into more power and speed.
The Throttle Position Sensor (TPS) is intended to inform the ECM (Engine Control Module) of the position of the throttle. With the information provided by this sensor, it is also possible to determine the amount of engine airflow and how much fuel needs to be injected for an ideal air/fuel mixture. If the Throttle Position Sensor circuit exhibits voltages that prove to be above the allowable voltages, the P1123 OBDII fault code will be set.
Symptoms of fault code P1123
- Check Engine
- Problems during acceleration.
- Black smoke ejection during engine start.
- Lower fuel efficiency.
Causes of OBD2 P1123
The reasons for the P1123 OBD2 diagnostic code being set are:
- The TPS circuit may have deficiencies in its wiring or connectors.
- The Throttle Position Sensor electrical connections could be faulty.
- The Throttle Position Sensor may be in poor condition.
Possible solutions of the DTC code P1123
The steps to follow to correct the DTC P1123 OBDII code are:
- Consult the Technical Service Bulletins.
- Inspect the condition of the throttle position sensor harness and connectors. Repair any conditions caused by corrosion or wear.
- Measure the Throttle Position Sensor voltages and compare those results to the manufacturer's specifications. If inconsistent voltages are found, make appropriate repairs.
- Check the TPS for damage. Follow the steps given by the manufacturer to diagnose this sensor and if you determine that it is defective, you should replace it.
