Throttle Position Sensor

The Ford Mondeo hit our roads in 1993, and has consistently been a sales success. Now on its 4th incarnation, it remains a drivers favourite.
For more information, visit the Ford Mondeo forum on TalkFord.com, the definitive resource site covering all Fords from the present day to the 1970's.

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Overview Guide
Ford Model:	Mondeo
Petrol/Diesel:	???
Estimated Cost:	???
Difficulty?	???
How long does this take?	???

Background

A bad TPS can have many effects:

• Hesitation on acceleration
• Rough idle
• Jerkiness
• Rough running

Means of identifying a bad TPS

Fault Code Reader

Extract the fault codes using a FCR (fault code reader), like one of Ford's WDS apparatuses, or a similar device which is EEC compliant.

Check TPS connector for cleanliness

1. Remove the connector from the TPS by pushing the securing spring, and then pulling the plug down.
2. Check for any corrosion or deposits. They should be spot clean.
3. Clean the connector using some contact spray, if need be.
4. Reconnect the connector and lock the securing spring back into place.

GDS (Ghetto Diagnostic System)

It is a foolproof method. It requires only a metal pin, a multimeter with high imput impedance (any digital model will do) and some crocodile clamp leads.

Measure Volt

1. Connect the black (negative) lead to a CLEAN engine part (ground)
2. Set the multimeter to the range that allows measurement of 0-15V (usually that will be 20V. Only DC will work.
3. Use a set of pliers to force the pin THROUGH the middle lead.
4. Connect the TPS to the connector
5. Connect the red lead to the pin
6. Switch on the ignition, but DO NOT START THE ENGINE.
7. The multimeter should read at least 0.4V.
8. Move the throttle SLOWLY through its entire range while watching the multimeter:
9. When the throttle is full open, the meter should read 4.2V or more. (max 5V).
10. Go through this process several times, as slowly as possible. You should see 0.01V steps.

Measure Ohm

With the TPS taken of the throttle body:

1. Look inside the connector on the TPS and you will see the letters A-C
2. Connect the black lead to A
3. Connect the Red lead to B
4. Set the multimeter to Ohm and 200K range
5. The display should read 0.5 Ohm's, turn the actuator in the TPS and it should gradually climb to 3.5 Ohm's.

The readout should, at all times, follow the linear motion of the throttle. If, the throttle is slowly opened, the readout should NEVER drop. If the throttle is slowly closed, the readout should NEVER rise. Not even for a short blip. If it falls to 0 at any given time, that is a 100% sure fire way to tell the TPS is gone.