M4.x
8051-based ECUs (the reset vector is an 8051 LJMP table) used almost
exclusively in Volvo vehicles.
| Era | 1994–2002 |
| File sizes | 64 KB (M4.3) or 128 KB (M4.4) |
| Variants | M4.3 (Volvo 850/960/S70/V70), M4.4 (Volvo S60/S70/V70/S80) |
| Vehicles | Volvo petrol |
Detection
A size gate (exactly 64 KB or 128 KB), then a DAMOS family token (/M4.3/,
/M4.4/), with an ident-digit fallback: a run of 20+ digits in the last ~8 KB
whose first ten start with 0261 and next ten with a Bosch SW prefix (1037,
1267, 2227, 2537).
Checksums: no family profile.