M132 (3B21)
Smart · 1.0 Turbo
2007–2014
"Mitsubishi 3B21 heart. Turbo version is peppy but fragile. SAM unit is the real villain. Budget carefully."
Mileage Risk Timeline
When problems typically appear — enter your mileage to see your risk zone
Known Issues 4
SAM unit failure (electrical)
▸Random electrical faults, no-start, warning light cascade
Signal Acquisition Module controls everything. Water ingress common cause. Refurbished units available.
Μονάδα SAM ελέγχει τα πάντα. Εισροή νερού κοινή αιτία. Ανακατασκευασμένες μονάδες διαθέσιμες. 500-1500 EUR.
Clutch actuator wear (automated manual)
▸Jerky gear changes, grinding, no-drive
Automated manual transmission. Clutch actuator motor wears. Learn-in procedure needed after replacement.
Αυτοματοποιημένο χειροκίνητο σασμάν. Μοτέρ ενεργοποιητή συμπλέκτη. Χρειάζεται εκπαίδευση μετά αντικατάσταση.
Turbo actuator failure
▸Limp mode, boost loss, turbo whistle changes
Electronic turbo actuator wears. Replacement without turbo removal possible on W451. Common failure.
Ηλεκτρονικός ενεργοποιητής turbo. Αντικατάσταση χωρίς αφαίρεση turbo δυνατή. Κοινή βλάβη.
Oil leak (valve cover / sump)
▸Oil spots under car, burning smell
Valve cover gasket and sump gasket prone to leaks. Rear engine = oil drips on exhaust = smell.
Φλάντζα καπακιού βαλβίδων και κάρτερ τρέχουν. Πίσω κινητήρας = λάδι στην εξάτμιση = μυρωδιά.
Models with M132 (3B21) 6
Other Smart Engines
Tuning Potential
Brabus 102hp
Frequently Asked Questions
Is the Smart M132 (3B21) reliable?
The Smart M132 (3B21) scores 52/100 with a verdict of CAUTION. It has 4 documented issues with total repair costs between €1,500 and €4,000.
What are the common problems with the M132 (3B21)?
The most common issues are:
- SAM unit failure (electrical) — critical, repair cost €500–€1,500, 50,000 km–120,000 km
- Clutch actuator wear (automated manual) — high, repair cost €400–€1,000, 50,000 km–100,000 km
- Turbo actuator failure — high, repair cost €400–€900, 60,000 km–120,000 km
- Oil leak (valve cover / sump) — moderate, repair cost €200–€600, 40,000 km–100,000 km
What cars use the Smart M132 (3B21)?
How much does it cost to repair the M132 (3B21)?
Total potential repair costs for all 4 known issues range from €1,500 to €4,000. The most expensive issue is typically .
What years was the M132 (3B21) produced?
The Smart M132 (3B21) was produced from 2007 to 2014. It is a 999cc I3 petrol turbo engine.
Verdict and scores are editorial opinions based on aggregated data. Learn about our methodology. Not a substitute for professional inspection.