Diagnostic Detection Logic

Throttle Position Sensor Operation:

DIAGNOSTIC DETECTION LOGIC
Background Information
- The throttle position sensor outputs a voltage which corresponds to the throttle valve opening angle.
- The engine control module checks whether the voltage is within a specified range. In addition, it checks that the voltage output does not become too large while the engine is idling.

When a Fault May Be Recorded
- Ignition switch : ON for more than 60 seconds
- More than 60 seconds after the the engine is started.

What Abnormality Sets This Code
- When the closed throttle position switch is ON (throttle at the idle stop), the sensor output voltage is 2 V or more for 4 seconds.
OR
- The sensor output voltage is 0.2 V or less for 4 seconds.

Effect on the Vehicle Systems
Vehicle enters Limp-in mode
- No increase in fuel injection amount during acceleration due to the unreliable throttle position sensor signal.

Probable Causes
- Throttle position sensor failed or maladjusted.
- Open or shorted throttle position sensor circuit, or loose connector.
- Closed throttle position switch ON malfunction.
- Closed throttle position switch signal wire shorted.
- Engine control module failed.

TROUBLESHOOTING HINTS
- The signals of the throttle position sensor are more important for control of the automatic transmission than for control of the engine; shifting "impact shocks" are produced if there is a malfunction of the throttle position sensor.
- If the voltage of the throttle position sensor is outside the standard value, check once again after making the throttle position sensor adjustment. In addition, if there are any indications that the fixed Speed Adjusting Screw throttle stop has been moved, adjust the fixed Speed Adjusting Screw.