Diagnostic Aids

WARNING: This page is about a different car, the 2002 Mercury Villager. However, it is still accessible from the selected car via links, so may be relevant.

Perform this test only when directed by QUICK TEST. This test is intended to diagnose the following:

Throttle Position (TP) sensor.
Binding and sticking throttle
Harness circuits; SIG RTN, TP SIG and VREF.
PCM.

For DTC P0120, TP PID should read approximately 80 percent with throttle valve fully open. With throttle valve fully closed, TP PID should read zero percent.

THROTTLE POSITION SENSOR OUTPUT

Throttle Position

⁽¹⁾ Voltage

Closed

1/4

1.3

Half Open

2.2

3/4

3.1

Fully Open

4.1

⁽¹⁾	Voltage values may vary plus or minus 15 percent.

Fig 1: Identifying TP Sensor Circuit & Harness Connector Terminals

Courtesy of FORD MOTOR CO.