Parts for your 2013 Subaru Forester-Throttle position sensors

2013 Subaru Forester throttle position sensor (TPS): purpose, servicing and replacement

Based on technical documentation for the 2013MY Subaru Forester (SH) — including the Factory Service Manual engine diagnostics and OBD-II fault coverage — this model absolutely uses a throttle position sensor. In fact, it uses a dual-signal throttle plate position sensor integrated into the electronic throttle body, alongside an accelerator pedal position sensor at the pedal. The service manual lists related diagnostics such as P0121, P0122, P0123 (Throttle Position Sensor A circuit) and P2135 (Throttle/Pedal Position Sensor A/B correlation), confirming the TPS is fitted and monitored by the ECU.

On the 2013 Forester, the TPS tells the engine computer exactly where the throttle plate is, so fuelling, ignition timing, idle speed control and transmission shift strategy (auto/CVT) all stay on-song. It also underpins cruise control and traction/stability systems. Because it’s part of an electronic throttle body, there’s no old-school cable or standalone adjustable sensor, Subaru designed the module as a matched assembly for accuracy and redundancy.

There’s no scheduled replacement interval for the TPS on this model. As part of routine servicing, it’s smart to check the throttle body for carbon build-up, verify the harness and connector condition, and scan for stored or pending DTCs even if the dash is quiet. When cleaning, avoid forcing the throttle plate by hand and use throttle-body-safe cleaner sparingly, keeping solvents off the electronics. If a TPS fault code returns after basic checks, the fix is typically a complete throttle body replacement. After any replacement or a flat battery, perform ECU learning/idle relearn (via a scan tool such as Subaru Select Monitor or the manual warm-up/idle procedure) so idle and tip-in feel return to normal.

• Common TPS-related symptoms: surging idle, hesitation, poor fuel economy, cruise control dropping out, “limp” mode, MIL on with P0121–P0123 or P2135.
• Tech tips: confirm 5V reference and ground at the connector, inspect for corrosion or stretched pins, clean the throttle bore, clear codes, and carry out idle learn. If readings are erratic or the two TPS tracks disagree, replace the throttle body and torque fasteners to the service manual spec.

Owners who keep connectors clean, the throttle body tidy, and learning procedures up to date tend to enjoy smooth throttle response and fewer nuisance lights under the bonnet — an easy win for reliability across Aussie and Kiwi conditions.

Does a 2013 Subaru Forester actually have a throttle position sensor?

Yes. The 2013 Forester uses an electronic throttle body with a built-in dual TPS, plus a separate accelerator pedal position sensor. The ECU cross-checks both for accuracy, which is why codes like P2135 can pop up if signals don’t align.

Can the TPS be replaced on its own, or does the whole throttle body need changing?

On this model, the TPS is integrated into the throttle body and isn’t serviced separately. If the sensor is faulty after wiring checks, the typical repair is replacing the throttle body assembly, followed by an idle relearn.

What are the signs of a failing TPS, and is it safe to drive?

Rough idle, stalling, a dead spot on throttle, cruise control dropping out, or limp-home behaviour with warning lamps are common. Short trips may be possible, but continued driving isn’t recommended — loss of power or surging can be unsafe, and faults can worsen.