Parts for your 2003 Ford Focus-Throttle position sensors

2003 Ford Focus throttle position sensor (TPS)

Yes, the 2003 Ford Focus uses a throttle position sensor. Ford’s Workshop Manual for Focus 2000–2004 (Fuel Charging and Controls, Section 303) specifies a TPS mounted on the throttle body across the 1.6/1.8/2.0 Zetec and 2.3 Duratec engines. Haynes’ Ford Focus Petrol & Diesel 1998–2005 manual and Autodata service info also list TPS testing and fault codes (P0120–P0124) for this model year. It’s a conventional, cable-operated throttle with a separate, non-adjustable TPS feeding the PCM.

The TPS tells the engine computer exactly how far the throttle blade is opened. With that signal, the Focus can sharpen fuelling and ignition timing, smooth idle quality, and manage auto trans shift timing. A healthy TPS helps the car respond crisply when they tip into the throttle, avoids flat spots, and keeps economy on song during everyday driving around town or out on the motorway.

It’s not a routine “replace by kilometres” item, but it does wear. Inside is a resistive track and wiper, after years of short trips, dust, moisture and vibration, the track can develop dead spots. Common clues include a check engine light with P0121/P0122/P0123, hesitation off idle, hunting or high idle, surging at steady speed, and harsh or late shifts in autos.

When servicing a 2003 Focus, a quick TPS health check is well worth it:

• Scan for related DTCs (P0120–P0124, P0220–P0229) and view live data for smooth throttle-angle change from about 0.5 V closed to ~4.5 V wide open.
• Inspect the connector for green corrosion, broken locks, or chafed wiring near the throttle body.
• Clean the throttle body bore and plate, don’t spray solvent into the TPS itself.

If replacement’s needed, it’s straightforward: disconnect the battery, unplug the sensor, swap it over with the new unit using the correct Torx screws, and re-connect. There’s no adjustment, if it has a slotted mount, align it exactly as the original. Finish with an idle relearn so the PCM settles down: start the car from cold, let it idle for a couple of minutes with all accessories off, then run the A/C and headlights for another minute, and take a short mixed drive with gentle acceleration and decel to closed throttle. That simple routine helps avoid a shaky idle or stalling after the job.

Done right, a fresh TPS restores clean throttle response and keeps the Focus feeling tidy and predictable on Aussie and Kiwi roads.

Popular questions

Does a 2003 Ford Focus have a throttle position sensor?
Yes. All 2003 Focus engines run a cable-operated throttle body with a separate, non-adjustable TPS. This is documented in Ford Workshop Manual fuel/engine management sections and widely covered in Haynes and Autodata procedures for that model year.

What are the signs of a failing TPS on a 2003 Focus?
Drivers may notice a check engine light (codes P0120–P0124), hesitation or flat spots on take-off, erratic or high idle, surging at a steady cruise, and harsh or late shifts in auto models. Live data will often show a jumpy or inconsistent throttle-angle signal.

Can the TPS be cleaned or should it be replaced?
The sensor itself isn’t serviceable. Cleaning the connector and fixing wiring issues can help, but if the internal track is worn or the signal is noisy, replacing the TPS is the fix. Cleaning the throttle body is separate and can be done as part of the job.