Parts for your 2003 Mitsubishi Lancer-Throttle position sensors

2003 Mitsubishi Lancer Throttle Position Sensor (TPS)

Yes, the 2003 Mitsubishi Lancer is fitted with a throttle position sensor. Mitsubishi’s factory workshop manual for the CS-series Lancer (Group 13A Fuel/Engine Electrical) shows a TPS mounted on the throttle body for the 4G94 2.0L petrol engine. The Mitsubishi ASA/EPC parts catalogue lists a “Sensor, Throttle Position” for 2002–2003 Lancer variants (common part numbers include MD628074/MD628318 depending on engine/market). General repair references such as the Haynes Lancer manual (2002–2007) and Autodata also specify TPS testing values (roughly 0.5 V at closed throttle to ~4.5 V at wide open). So it’s absolutely a relevant, fitted component on this model.

The TPS tells the engine control unit how far the throttle plate is open. On a cable-operated 2003 Lancer throttle body, the sensor tracks the driver’s pedal input so the ECU can manage fuel delivery, ignition timing and automatic transmission kickdown behaviour. When it’s healthy, throttle response is crisp, idle is steady and fuel economy stays on-song. When it’s not, drivers may cop flat spots, erratic idle, harsh shifts or a glowing check engine light with codes like P0120–P0123 or P0221.

While the TPS isn’t a routine replacement item, it’s wise to include it in servicing checks for a 2003 Mitsubishi Lancer. A quick visual and electrical inspection under the bonnet goes a long way:

• Look for cracked wiring, loose connectors and corrosion at the TPS plug.
• Clean the throttle body and ensure the throttle plate moves freely.
• If drivability’s off, test TPS signal sweep with a scan tool or multimeter for smooth, linear voltage change.

If replacement’s needed, it’s a simple driveway job for a competent DIYer:

1. Disconnect the battery, remove the intake ducting and unplug the TPS.
2. Undo the mounting screws, swap the sensor, and refit carefully. Some variants are slotted for alignment—set closed-throttle voltage to spec if adjustable, otherwise let the ECU relearn idle.
3. Reattach the intake, reconnect the battery, clear codes and perform an idle learn (let it idle with all accessories off until warm, then a short drive cycle).

Quality OEM-equivalent sensors tend to last years. Using dielectric grease on the connector, keeping the throttle body clean and fixing any vacuum leaks will help the TPS live a long, trouble-free life on a 2003 Lancer.

Where is the TPS on a 2003 Lancer?

It’s bolted to the side of the throttle body, opposite the cable linkage. You’ll see a small, black plastic sensor with a three-pin connector. Access is via the air intake snorkel—remove that and the plug and mounting screws are right there.

What are common signs the TPS is failing on this model?

Flat spots on take-off, hunting or high idle, poor fuel economy, harsh or delayed auto kickdown and a check engine light are the usual clues. Scan for codes like P0120–P0123, then check the wiring and do a smooth voltage sweep test.

Does a new TPS need calibration or relearn?

Some replacement sensors are fixed and need no adjustment, others have slotted holes and should be set to the specified closed-throttle voltage using a multimeter or scan data. After fitting, perform an idle relearn so the ECU stabilises idle control.