CARFACTBOOK / DIAGNOSTIC REFERENCE

Start with the symptom. Follow the evidence.

Choose a symptom and your exact chassis when possible. Each next check follows the result you record—not a guessed failed part. CarFactBook keeps a traceable path and prepares a practical mechanic handoff.

Symptom first

What are you seeing?

Electrical

Won't start / hard starting

Check reviewed reports for Toyota Sienta NHP170G.

Electrical

Warning light or message

Check reviewed reports for Toyota Sienta NHP170G.

Cooling

Overheating / running hot

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A/C / climate

A/C not cold

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Suspension / steering

Vibration / shaking

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Brakes

Brake problem

Check reviewed reports for Toyota Sienta NHP170G.

Hybrid / EV system

Hybrid-system problem

Check reviewed reports for Toyota Sienta NHP170G.

Fuel / emissions

Poor fuel economy

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Choose an exact vehicle

Selected: Toyota Sienta NHP170G · 2015–2022

Diagnostics v3 · Structured symptom flow

Hybrid-system problem — structured test-result path

0 results recorded
Safety boundary. High-voltage hybrid/EV systems can be hazardous. Do not open or probe high-voltage components unless you are trained and equipped for the vehicle.
Next reachable check

Is there an exact hybrid-system warning or diagnostic code?

The exact message/code is stronger evidence than guessing which hybrid component failed.

Mechanic handoff summary

Further evidence required. 0 reachable results recorded.

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Preparing Diagnostics v3 handoff…

After a mechanic checks or repairs the car

Close the loop with the actual diagnosis, repair, part, cost and follow-up. The exact vehicle, symptom area and the test-result path above are prefilled, but you can edit them before submitting.

Choose an exact vehicle above to prepare a repair-outcome report.Reports remain pending until CarFactBook reviews them. A diagnostic path or external test result never becomes a confirmed diagnosis automatically.
Toyota Sienta NHP170G

Useful references for your exact car

These references relate to the selected symptom. They do not identify a faulty component or recommend replacing it. Confirm equipment, production period and source caveats for your individual car.

Verified facts

Engine coolant →

Toyota Super Long Life Coolant · 5.0 L reference capacity

NHP170G hybrid engine cooling circuit.

Toyota Motor Corporation · Verified 2026-10-02

Hybrid traction battery architecture →

Nickel-metal hydride · 20 units · 6.5 Ah

High-voltage traction battery; separate from the auxiliary 12V battery.

Toyota Motor Corporation · Verified 2026-10-02

Hybrid transaxle fluid →

Toyota Genuine ATF WS · 3.4 L reference capacity

Toyota says to consult a dealer when replacement is necessary; no replacement interval is inferred here.

Toyota Motor Corporation · Verified 2026-10-02

Inverter coolant →

Toyota Super Long Life Coolant · 1.8 L reference capacity

Separate hybrid inverter cooling circuit.

Toyota Motor Corporation · Verified 2026-10-02

Key battery →

CR2032 with Smart Entry & Start; CR2016 without it

Key type/equipment determines the battery.

Toyota Motor Corporation · Verified 2026-10-02

Maintenance

Documented service references; your service history determines what is due.

Hybrid transaxle fluid service

Condition based

Use Toyota Genuine ATF WS; the manual lists a 3.4 L reference capacity.

Toyota states to consult a dealer when replacement is necessary; CarFactBook does not invent an interval.

Toyota Japan Sienta Hybrid 2020 owner manual ↗ · Verified 2026-10-02

Engine and inverter coolant service

Condition based

Use Toyota Super Long Life Coolant; reference capacities are 5.0 L for the gasoline engine circuit and 1.8 L for the inverter circuit.

No replacement interval is inferred from the specification table.

Toyota Japan Sienta Hybrid 2020 owner manual ↗ · Verified 2026-10-02

Key battery replacement

Condition based

Use CR2032 with Smart Entry & Start; use CR2016 without Smart Entry & Start for the documented NHP170G key systems.

Key system/equipment controls the applicable battery. Replace when required; no fixed interval is inferred.

Toyota Japan Sienta Hybrid 2020 owner manual ↗ · Verified 2026-10-02

Full exact-car maintenance schedule →

Parts / fitment

Reference specifications, not a shopping list or proof that these parts need replacement. Fitment conditions still apply.

2LM traction motor architecture

2LM AC synchronous motor · 45 kW (61 PS) · 169 N·m

High-voltage traction-system reference; not a DIY replacement instruction.

Toyota Motor Corporation source ↗ · Verified 2026-10-02

Hybrid traction-battery architecture

Nickel-metal hydride · 20 units · 6.5 Ah

High-voltage traction battery; separate from the auxiliary 12V battery.

Toyota Motor Corporation source ↗ · Verified 2026-10-02

Hybrid transaxle fluid

Toyota Genuine ATF WS · 3.4 L reference capacity

Toyota says to consult a dealer when replacement is necessary; no replacement interval is inferred here.

Toyota Motor Corporation source ↗ · Verified 2026-10-02

Full exact-car parts references →

Reviewed repair evidence

Hybrid-system problem

0 related reports

Reports are matched by related system category for Toyota Sienta NHP170G. Compare the recorded symptom and outcome; a repair on another car does not diagnose yours.

No reviewed match yet. CarFactBook will not manufacture a likely cause just to fill this screen. Check the exact vehicle facts or contribute a real repair outcome through Problems.

Browse or contribute reviewed problem & repair evidence →