Parts for your 2018 Nissan Serena-Throttle position sensors

2018 Nissan Serena throttle position sensors (TPS)

Technical documentation confirms the 2018 Nissan Serena (C27) does use throttle position sensors. Nissan’s C27 Serena Service Manual (Engine Control/EC section) describes an Electronic Throttle Control actuator with two built‑in throttle position sensors for redundancy. Nissan diagnostic tooling (CONSULT-III plus) exposes live data items for these sensors, and the factory parts catalogue lists the “Throttle Chamber/Throttle Body Assy” with the sensors integrated. Nissan technical training material on Electronic Throttle Control also outlines this dual-sensor arrangement used on MR-series engines, including the MR20DD found in the C27 Serena and S-HYBRID variants.

On the 2018 Serena, the throttle position sensors live inside the electronic throttle body and constantly report how far the throttle plate is open. That lets the engine computer fine‑tune fuelling, spark timing, and idle speed so the van drives smoothly and sips fuel rather than gulps it. This model actually has two TPS tracks that cross‑check each other. If their readings don’t line up, the ECM sets a fault code and can go into a reduced‑power (limp) mode to protect the drivetrain.

Because the sensors are integrated, they’re not a separate service item. When they wear or drift out of spec, the practical fix is to replace the throttle body assembly. During routine servicing, a good workshop will keep an eye on TPS health by checking live data, confirming clean and stable idle, and inspecting the throttle body and wiring. A light clean of the throttle bore and plate with an appropriate throttle-body cleaner helps prevent sticky operation, but the plate shouldn’t be forced or propped open—let the motor do the moving.

Common signs the TPS/throttle body needs attention on a C27 include:

• Erratic idle, stalling, or hunting at traffic lights
• Sluggish take‑off or sudden surges
• Engine light on with codes like P0120–P0124, P2135, or mismatch faults
• Poor fuel economy and hesitant throttle response

Replacement tips for this Serena: choose a quality OEM‑spec throttle body and a fresh gasket, and don’t forget the relearns. After fitting, perform accelerator pedal released position learning, throttle valve closed position learning, and idle air volume learning using a capable scan tool (CONSULT‑III plus or equivalent is ideal). Clear any stored and pending codes, verify stable idle and smooth throttle response, and road‑test under mixed conditions. As preventative care, many techs inspect and, if needed, clean the throttle body every 40,000–60,000 kilometres, check the loom for chafing near the throttle, and ensure battery voltage is healthy so the electronic throttle behaves properly—especially important on S‑HYBRID models where low 12‑volt support can amplify drivability niggles.

Does the 2018 Nissan Serena have a separate TPS, or is it built into the throttle body?

It’s built in. The C27 Serena’s throttle position sensors are part of the electronic throttle body assembly. If the sensor fails, the usual repair is to replace the complete throttle body rather than a standalone TPS.

Is a throttle relearn needed after throttle body/TPS replacement on a C27 Serena?

Yes. After replacement or a thorough clean, the ECM needs throttle and idle relearns. A scan tool makes this straightforward and helps avoid high idle, stalling, or delayed throttle response. Skipping relearns is a common cause of post‑repair drivability issues.

Which fault codes point to a TPS issue on a 2018 Serena?

Typical codes include P0120–P0124 (TPS circuit range/performance), P0220/P0223, and P2135 (correlation mismatch between the dual sensors). Intermittent versions of these often trace to wiring or connector problems at the throttle body, so a visual and wiggle test is worthwhile before replacing parts.