OBD0 Engine Control Units (1988–1991)
OBD0 refers to the non-standardized engine control units used in Honda and Acura vehicles from 1988–1991, primarily featuring MPFI and electronic advance distributors.
"OBD0" is a colloquial term rather than an official industry standard. It refers to the Multi-Point Fuel Injection (MPFI) ECUs produced between 1988 and 1991, which utilize Electronic Advance Distributors.
Note
While vehicles produced prior to 1988, as well as specific Accord, Prelude, and V6 models of this era, technically utilize early electronic control systems, they are generally categorized as "pre-OBD" due to significant architectural differences.
MPFI ECUs (1988â1991)
The following ECUs are commonly associated with the 1988â1991 MPFI platform:
| ECU Code | Application | Engine |
|---|---|---|
| PG7 | 88â89 Integra | D16A1 |
| PM6 | 88â91 Civic/CRX Si | 1.6L SOHC |
| PM7 | 89â91 Civic Si (JDM) | DOHC ZC |
| PM7 | 89â91 CRX (EDM) | D16A8/A9 |
| PM8 | 88â91 CRX HF | D15 |
| PR3 | 89â91 JDM B16A | B16A |
| PR5 | 90â91 JDM Integra ZXi | 1.6L SOHC |
| PW0 | 89â91 JDM/Euro B16A | DOHC VTEC |
| PR4 | 90â91 Integra LS/GS | B18A |
| PS9 | 88â91 4-Door Civic EX (Auto) | 1.6L SOHC |
Prelude and Accord Series
The PH3 and PK2/PK3 ECUs share nearly identical PCB architecture.
- PK2: 88â91 Prelude Si (B20A, 140 HP)
- PH3: 86â89 Accord 2.0Si (B20A)
DPFI ECUs
Dual-Point Fuel Injection (DPFI) systems were produced concurrently with the MPFI units for base-model vehicles:
- PM5: 88â91 Civic/CRX DX (DPFI D15B)
- PM9: 88â91 Civic Base Model (DPFI D15B)