Parts for your 2020 Nissan Serena-Starter motor

2020 Nissan Serena starter motor: what’s fitted and what to service

Technical references including the Nissan C27 Serena Service Manual (STR—Starting System, EC—Engine Control) and Nissan e-POWER system descriptions make it clear that starter-motor fitment depends on the variant. The 2020 Serena e-POWER does not use a conventional 12‑volt starter motor, as the petrol engine is cranked by the generator motor under inverter control. The 2.0‑litre S‑HYBRID (MR20DD) models, however, do have a conventional starter motor in the starting circuit, alongside the belt‑driven “ECO Motor” alternator/starter used for idle‑stop assistance. Press and dealer technical briefs for C27 support the same distinction.

For the e-POWER Serena, a traditional starter motor isn’t relevant. It’s a series hybrid: the EM57 drive motor moves the vehicle, while the 1.2‑litre engine only runs as a generator. When the engine needs to start, the generator unit cranks it directly, so there’s no separate 12‑volt starter or alternator. A DC‑DC converter keeps the 12‑volt system charged, which also helps reduce noise and wear associated with conventional cranking.

For S‑HYBRID owners, the 2020 Serena does have a conventional starter motor. Here’s what that part does and how to look after it during servicing.

The starter motor’s job is to spin the MR20DD engine fast enough for it to catch. When the key or start button is pressed, the solenoid pushes the pinion into the flywheel ring gear and the motor cranks the engine. On S‑HYBRID models, the belt‑driven ECO Motor handles most quick idle‑stop restarts, but the conventional starter is still used for primary or cold starts and as a fallback—so it matters.

Good servicing habits keep the starter happy. Battery health is key: low voltage is the number‑one starter killer. A workshop should check the 12‑volt battery state of charge, load‑test it, and clean/tighten the battery and earth connections. If cranking is slow or there’s just a click, a voltage‑drop test across the main starter cable and engine earth (aiming for minimal drop) helps pinpoint wiring versus starter faults. Oil leaks onto the starter, missing heat shields and tired engine mounts can shorten its life—worth inspecting under the bonnet.

Replacement is straightforward for a pro: isolate the battery, access the unit from above/under‑car depending on spec, unplug the solenoid connector, remove the main cable and mounting bolts, swap in a quality new or remanufactured unit (with new solenoid), and torque fasteners to spec. No coding is normally required. Typical labour is around an hour or so, but varies with tooling and access. Choosing the correct tooth count and clocking is important, a workshop will match the part using VIN.

• Watch for symptoms: slow crank, single click, grinding on start, intermittent no‑crank.
• Maintain: healthy 12‑volt battery, clean terminals, solid engine/body earths.
• When replacing: verify part number, include the solenoid, inspect ring gear condition.

Technical sources referenced: Nissan C27 Serena Service Manual (STR—Starting System, EC—Engine Control), Nissan e‑POWER technical brief/training materials for C27/Note, and Nissan S‑HYBRID “ECO Motor” system descriptions used in C26/C27 Serena.

Popular questions about the 2020 Nissan Serena starter motor

Does the 2020 Serena e‑POWER have a starter motor?
No. The e‑POWER’s engine is started by the generator motor via the inverter, so there’s no conventional 12‑volt starter or alternator. The 12‑volt system is supported by a DC‑DC converter from the high‑voltage battery.

Where is the starter motor on a 2020 Serena 2.0 S‑HYBRID?
It’s mounted low on the engine/transmission side, engaging the flywheel ring gear. Access varies by trim and under‑covers, many techs reach it from underneath after isolating the battery and removing splash shields for room.

What are common signs the S‑HYBRID starter motor is failing?
Slow cranking, a single click with no spin, intermittent no‑crank, or grinding as the pinion disengages. Always rule out a weak 12‑volt battery and poor earths before condemning the starter itself.