Parts for your 2004 Toyota Crown-Throttle position sensors

2004 Toyota Crown throttle-position-sensor — what it does and how to look after it

Technical sources for the S180-series 2004 Toyota Crown confirm it does use a throttle-position sensor (TPS). Toyota’s New Car Features (NCF) and Repair Manual for the GR-series engines describe Electronic Throttle Control (ETCS-i), where a dual-track TPS is built into the throttle body alongside the throttle actuator motor. The Electronic Parts Catalogue also lists the TPS as part of the throttle body assembly, and the factory diagnostic list for this model includes TPS-related DTCs such as P0120–P0124 and P2135. So yes — this Crown absolutely relies on a TPS.

On the 2004 Crown, the TPS tells the engine control module exactly how far the throttle plate is open. That info is crucial for fuelling, ignition timing, idle stability, cruise control, transmission shift logic, and traction/vehicle stability systems. With ETCS-i there’s no traditional throttle cable, the ECU compares accelerator pedal sensors with the TPS feedback and drives the throttle motor for smooth, safe response.

There’s no fixed service interval for the TPS, but it’s smart to check it during regular servicing. Because the TPS is integrated into the throttle body on most 2004 Crowns, maintenance is mostly about keeping that assembly healthy:

• Inspect the throttle body for carbon build-up, clean around the plate with a sensor-safe cleaner. Don’t drown the shaft area or force the plate by hand.
• Check the TPS/throttle body connector and wiring for corrosion, cracked insulation, or loose pins.
• Scan live data to confirm smooth throttle angle change and sensible correlation with accelerator input, investigate DTCs like P0120–P0124, P2135.

Common signs the TPS/throttle body is playing up include erratic idle, hesitation, surging, poor fuel economy, or limp-home behaviour. Before condemning the sensor, rule out vacuum leaks, a sticky throttle plate, or accelerator pedal sensor issues.

Replacement on these models typically means swapping the whole throttle body (new gasket recommended). Follow the factory torque specs, then carry out throttle/idle learning with a scan tool (Toyota Techstream or equivalent) and clear any DTCs. A battery reset alone won’t always relearn the target idle. When sourcing parts, choose quality OEM or reputable aftermarket to avoid drivability gremlins.

If the Crown’s clocking up big kilometres or showing the symptoms above, bundling a throttle body clean and electrical checks into the next service is a low-cost way to keep it running sweet as.

FAQs

Does the 2004 Toyota Crown have a separate TPS or is it built-in?
It’s built into the electronic throttle body on most 2004 Crowns. Toyota designed the TPS and throttle motor as a single assembly for reliability and accurate feedback. That means replacement usually involves the complete throttle body rather than a bolt-on sensor swap.

What are the typical TPS fault codes on a 2004 Crown?
Common codes include P0120–P0124 (TPS circuit range/performance and sensor switching) and P2135 (throttle/pedal position sensor voltage correlation). If these appear, check wiring and clean the throttle body, then verify live data before replacing parts.

Do I need to relearn the throttle after work on the TPS/throttle body?
Yes. After cleaning or replacing the throttle body, perform a throttle/idle learn with a suitable scan tool. This helps the ECU relearn the target idle and throttle position, preventing hunting or stalling.