Parts for your 2001 Mitsubishi Lancer-Throttle position sensors

2001 Mitsubishi Lancer throttle-position sensor: what it does, where it lives, and how to look after it

Based on the Mitsubishi Lancer factory workshop manuals (CE/CS series), Mitsubishi ASA parts catalogues, and trade references such as Autodata and Haynes, the 2001 Mitsubishi Lancer is fitted with a throttle-position sensor (TPS). It’s mounted on the throttle body of the cable-operated throttle, across common engines like the 4G15, 4G93 and 4G94. The ECU uses the TPS signal for fuelling, ignition timing, idle control and kickdown logic (auto). OBD‑II fault codes related to this sensor typically include P0120–P0123 and P0221.

The TPS on a 2001 Lancer is a variable resistor that tracks how far the throttle plate is opened. At closed throttle it sends a low voltage to the ECU, rising smoothly towards wide-open throttle. That smooth, predictable change helps the ECU manage crisp throttle response, steady idle, and clean gear changes. If the signal goes noisy or out of range, drivers may notice flat spots, hunting idle, stalling at intersections, harsh shifts in autos, higher fuel use, or a check engine light.

As part of routine servicing, it’s smart to give the throttle body and TPS a bit of attention. A careful clean of the throttle bore and plate with proper throttle cleaner often restores stable idle. The TPS itself shouldn’t be drowned in solvent, instead, check the connector for corrosion, a loose fit, or broken wiring near the plug. If the Lancer’s TPS is the slotted, adjustable type, refitting or replacement may require setting the closed-throttle voltage with a scan tool or multimeter so the ECU sees the right base value. Some variants are non-adjustable and simply bolt on—handy if you’re swapping like-for-like.

Replacement is typically straightforward: disconnect the battery, unplug the sensor, remove the two screws, swap the unit, and align the tang with the throttle shaft. Avoid overtightening the screws, as the throttle body is alloy. Once fitted, clear any codes and perform an idle or throttle relearn if specified by the service data. After that, a quick road test should confirm smooth tip-in and consistent shift behaviour.

• Watch for symptoms: surging idle, hesitation, sudden drop in power, or erratic auto shifts.
• Scan for codes P0120–P0123, check live data for a smooth 0–100% sweep with no dropouts.
• Inspect wiring and earths before condemning the sensor—many “sensor faults” are actually connector issues.

A well-sorted TPS keeps the 2001 Lancer feeling responsive and thrifty, whether it’s commuting around town or cruising Kiwi and Aussie highways.

Popular questions

Where is the TPS on a 2001 Mitsubishi Lancer and how hard is it to replace?
It’s bolted to the side of the throttle body, opposite the cable pulley. Replacement is usually a driveway job: disconnect the battery, unplug the connector, remove two screws, swap the sensor, and refit. On adjustable units, set closed-throttle voltage with a scan tool or multimeter before road testing.

What are the common symptoms of a failing TPS on this model?
Typical signs include a hunting or high idle, hesitation on take-off, “dead spots” when accelerating, harsh or confused shifting in autos, and a check engine light with codes like P0122 or P0123. Fuel economy can also drop because the ECU can’t trust throttle angle.

Do you need a throttle or idle relearn after replacing the TPS?
Many Lancer variants will settle on their own after a short drive cycle, but following the workshop procedure is best practice. This can include clearing codes, key-on/throttle-closed steps, and a brief idle stabilisation. A scan tool helps confirm the ECU now reads the correct closed and wide-open throttle values.