Parts for your 2012 Mitsubishi Lancer-Throttle position sensors

2012 Mitsubishi Lancer Throttle Position Sensor (TPS)

Yes, the 2012 Mitsubishi Lancer uses a throttle position sensing system. Technical references including the Mitsubishi Lancer service manual (Electronic Throttle Control/ETACS section for 4B11/4B12/4B11T engines), common OBD-II diagnostics for this model (DTCs P0120–P0123, P2135 relating to throttle position circuits), and workshop guides such as Haynes/Autodata confirm an electronically controlled throttle body with dual built‑in throttle position sensors and a separate accelerator pedal position (APP) sensor. Mitsubishi’s parts catalogues also list the throttle body as an assembly with the TPS integrated, meaning it’s not typically serviced as a standalone sensor.

On the 2012 Lancer, the throttle position sensor’s job is to tell the engine control unit exactly how far the throttle plate is open. Because the car runs drive‑by‑wire, the throttle body houses a motor and a pair of TPS tracks for redundancy. The ECU uses those signals to manage fuelling, ignition timing, idle control and, on CVT/auto models, shift strategy. It also ties into cruise control, stability control and air‑conditioning load compensation, helping the Lancer feel smooth and responsive in day‑to‑day driving across Aussie and Kiwi roads.

Signs the TPS system needs attention can include erratic idle, flat spots off the line, sudden loss of power (limp mode) and the check‑engine light. Common fault codes for this generation include P0121 (range/performance) and P2135 (throttle/pedal correlation). A quick scan‑tool check will show if the throttle angle signal is smooth and consistent from closed to wide‑open.

For servicing, the TPS on these Lancers is integrated with the throttle body, so replacement usually means fitting a complete throttle body assembly. It’s worth confirming with a parts lookup by VIN, as separate TPS units aren’t standard on this model. Whenever the throttle body is removed, replace the gasket, torque the fasteners to spec, and carry out an idle/throttle relearn. Many workshops use a scan tool to run the adaptation, if DIY, follow the factory procedure (key‑on cycles and stable battery voltage) to help the ECU relearn the throttle stops without dramas.

Good maintenance goes a long way. Clean the throttle bore and plate with throttle‑safe cleaner during routine servicing—just avoid soaking the shaft area to protect the internal sensor. Keep the battery and grounds healthy, as voltage dips can trigger throttle plausibility faults. If the car racks up the kilometres around town, scheduling a throttle clean and adaptation every couple of services keeps take‑off and idle nice and tidy.

• If replacing: use quality OEM‑spec throttle body assemblies
• Perform throttle/idle relearn after battery disconnect or throttle work
• Verify with a scan tool: smooth TPS percentage and matching APP signals

Popular questions about 2012 Mitsubishi Lancer throttle position sensors

How can someone tell if the TPS is failing on a 2012 Lancer?
They’ll typically notice uneven idle, hesitation on light throttle or sudden limp mode. A scan tool will often show stored codes like P0121 or P2135, and live data may reveal jumpy or mismatched throttle angle readings. If cleaning the throttle body and running a relearn doesn’t settle it, further diagnosis of the throttle body assembly and wiring is recommended.

Can the TPS be replaced separately from the throttle body?
On most 2012 Lancer variants, the TPS is built into the electronic throttle body and isn’t supplied as a separate service part. The usual fix is replacing the complete throttle body assembly. Check the exact engine code and VIN with a parts catalogue to be sure, but separate TPS replacement is uncommon on this model.

Is a throttle relearn needed after servicing?
Yes. Any time the battery is disconnected, the throttle body is cleaned or replaced, or the ECU is reset, a throttle/idle relearn helps the ECU re‑establish the throttle stops. Many workshops perform this with a scan tool, without one, follow the service manual’s key‑on procedure and allow the ECU to finalise adaptation before driving off.