Parts for your 2013 Toyota Mark x-Throttle position sensors

2013 Toyota Mark X throttle-position-sensors

Technical sources confirm the 2013 Toyota Mark X (GRX130/133, 4GR‑FSE 2.5L and 2GR‑FSE 3.5L V6) does use throttle-position-sensors. Toyota’s Electronic Throttle Control System – intelligent (ETCS‑i) integrates dual throttle position sensors inside the throttle body, along with a throttle control motor. This is detailed in the Toyota Mark X GRX130 series Repair Manual (SFI/ETCS‑i section) and the Toyota Electrical Wiring Diagram, and is also visible in Techstream Data List items “Throttle Position Sensor No.1/No.2 (VTA1/VTA2)”. Relevant DTCs include P0121, P0122, P0123, P0222, P0223 and P2135, all of which reference the throttle-position-sensors and their correlation.

On the 2013 Mark X, the throttle-position-sensors tell the ECU exactly where the throttle plate is, allowing smooth, precise drive‑by‑wire control. The sensors are redundant (two tracks) for safety, constantly cross‑checked against each other and the accelerator pedal sensor. That means crisp throttle response, steady idle and proper transmission shift timing when everything’s healthy.

As part of regular servicing, it’s worth keeping an eye on throttle behaviour. If there’s a rough idle, flat spots, limp mode, or the MIL pops up with one of the TPS‑related codes, it’s time for a check under the bonnet. Because the Mark X’s throttle-position-sensors are built into the throttle body, the usual fix for an internal sensor fault is replacing the entire throttle body assembly rather than the sensor on its own.

Good workshop practice for this model includes cleaning the throttle bore and plate with the correct cleaner (engine off), inspecting the connector and loom for corrosion or chafing, and scanning live data. Techstream or an equivalent scan tool should show smooth, linear VTA1/VTA2 voltage changes with pedal movement and proper correlation. After any throttle body replacement or if the battery’s been off for ages, perform the “Throttle Valve Closed Position” and idle learning routine with a scan tool to settle the idle. Many owners notice better drivability after this reset.

• When to act: MIL on with P0121/P2135, erratic idle, surging, or sudden loss of power.
• Service tip: Always check accelerator pedal sensor data too, it works hand‑in‑hand with the throttle-position-sensors.
• Replacement: Use a quality throttle body assembly, initialise the throttle and verify VTA1/VTA2 correlation post‑fitment.

Does the 2013 Mark X actually have a throttle-position-sensor?

Yes. The 2013 Mark X uses dual throttle-position-sensors integrated into the throttle body as part of Toyota’s ETCS‑i. They provide real‑time throttle plate position feedback that the ECU cross‑checks for safety and smooth control.

What are common signs the throttle-position-sensors are playing up?

Watch for an engine light with codes like P0121 or P2135, unstable idle, hesitation off the line, poor fuel economy, or limp mode. A scan of VTA1/VTA2 should show smooth, matching signals, glitches or mismatches point to an issue.

Can the sensor be replaced separately from the throttle body?

On this model, the sensors are part of the throttle body assembly and aren’t serviced separately. If the internal sensor fails, the practical repair is a new or quality remanufactured throttle body, followed by throttle relearn with a scan tool.