HiAce Van (2KD): Rough idle / vibration
Suspect the injectors first. On the 2.5L 2KD diesel, idle becomes unstable when the injectors can't spray properly, with white smoke and vibration alongside. Next come a clogged fuel filter and the supply pump (high-pressure fuel pump), tied. After that the SCV (the valve that meters fuel into the pump); sometimes replacing only the SCV fixes it.
What to suspect, in order
Repair cost estimates are shown only for parts with three or more cases that record a cost.
- How to tell (things you can check yourself)
- Idle vibration plus black or white smoke and loud combustion clatter. The scan tool's per-cylinder correction values show it.
- If you leave it
- Poor combustion makes more soot, and on DPF-equipped vehicles clogs the DPF too.
- Typical model years and mileage
- 2004–2006 model years、111,500–280,000 km (median 190,377 km)
- How to tell (things you can check yourself)
- Filter overdue for replacement; symptoms worse after refuelling or on cold mornings. The cheapest thing to check first.
- If you leave it
- A blockage prevents pressure build-up and loads the pump.
- How to tell (things you can check yourself)
- Revs hunt first thing in the morning or at traffic lights, starting gets harder, the check engine light may come on. Progresses to stalling.
- If you leave it
- Once it can't build fuel pressure the engine stops on the move. Repairs tend to be expensive, so act early.
- Typical model years and mileage
- 79,400–239,400 km (median 157,000 km)。Concentrated on high-mileage vehicles.
- How to tell (things you can check yourself)
- Idle hunts up and down rhythmically, or the engine catches for a moment when cold and stalls. An updated part exists for the 2KD, and there are cases fixed by replacing only the SCV rather than the whole pump.
- If you leave it
- Driving with erratic fuel pressure control brings repeated stalling and warning lights.
Other single cases: Common rail
Confirm with an inspection. Check when the fuel filter was changed, then have a workshop measure fuel pressure.
FAQ
- Will a fuel additive fix it?
- Light deposits may respond, but it does nothing for worn pumps or injectors. If the vibration persists, get it checked.
- How much does the repair cost?
- A fuel filter is cheap; a supply pump or injectors mean serious parts costs. Having it diagnosed first is cheaper in the end.
Cases (what it was, and how it was fixed)
Each collected case: model year, mileage, symptom combination, cause and parts replaced, cost and source. Facts only, no quoted text.
Any other symptoms? Tap the ones that apply to filter the cases and see which parts were common for that combination.
| Code / year | Mileage | Other symptoms | Cause / parts replaced | Cost | Source |
|---|---|---|---|---|---|
| KDH200 | 260,000 km | Hard starting / takes a long time | Injectors、Supply pump (high-pressure fuel pump)、Common rail、Fuel filter | — | Shop blog (JP) |
| KDH200 | — | Check engine light on、Stalling / stops while driving | Suction control valve (SCV)、Fuel filter | — | Shop blog (JP) |
| KDH205 2004 model year | 247,954 km | No acceleration / lack of power | Injectors、Intake manifold、EGR valve | — | Shop blog (JP) |
| KDH200 | 300,000 km | White smoke | Injectors、Suction control valve (SCV)、Fuel filter | — | Shop blog (JP) |
| KDH225 2005 model year | 123,000 km | White smoke、Burning smell | Injectors | — | MLIT (JP) |
| KDH200 2006 model year | 132,800 km | White smoke | Injectors | — | MLIT (JP) |
| KDH200 2005 model year | 157,000 km | White smoke、Stalling / stops while driving | Supply pump (high-pressure fuel pump) | — | MLIT (JP) |
| KDH205 2006 model year | 100,000 km | — | Injectors | — | MLIT (JP) |
| KDH205 2005 model year | 60,000 km | Cranks but won't start、Stalling / stops while driving | Supply pump (high-pressure fuel pump) | — | MLIT (JP) |
Costs are as recorded in each case and vary by vehicle condition, region and shop. "—" means not recorded.
For DIY repairers: find the part
Searches by the No.1 part name. Always confirm fitment by model code.
Sources
- MLIT Vehicle Defect Information Hotline (Japan)（5 cases）
- Repair shop blogs (Japan)（4 cases）
Created by processing the Vehicle Defect Information Hotline data (Ministry of Land, Infrastructure, Transport and Tourism, Japan) (https://renrakuda.mlit.go.jp/renrakuda/opn.html)
No text is quoted from these sources. Only the facts of each case (model, symptom, cause, cost) are aggregated.
Reviewed by Tama Inc. (workshop certified by the Kanto District Transport Bureau) Reviewed on 2026-09-11 Updated 2026-09-13
This page shows what to suspect first, based on aggregated nationwide repair cases and our own experience. Always confirm the cause with an inspection. Repair costs are medians and ranges from the cases; they vary by vehicle condition, region and workshop.
2KD rough idle is SCV and injectors. Fit a new fuel filter first and see — the cheapest step with the fewest misses.