PR4 ECU Technical Reference
Technical overview of the PR4 ECU, detailing the differences between the OBD0 and OBD1 variants used in Acura Integra applications.
The PR4 ECU was utilized in Acura Integra applications and exists in two distinct generations corresponding to OBD0 and OBD1 standards.
Variant Overview
The PR4 platform underwent significant hardware revisions to accommodate the transition from OBD0 to OBD1 engine management systems.
| Variant | OBD Generation | Primary Application |
|---|---|---|
| PR4 (OBD0) | OBD0 | 1990â1991 Acura Integra (B18A1) |
| PR4 (OBD1) | OBD1 | 1992â1993 Acura Integra (B18A1) |
Technical Specifications
Important
While the PR4 designation is shared, OBD0 and OBD1 variants are not directly interchangeable due to differences in connector pinouts, internal processor architecture, and sensor signal processing.
OBD0 PR4
The OBD0 version of the PR4 is characterized by its dual-plug connector layout and reliance on the older Honda OBD0 architecture. It is commonly found in the DA chassis Integra.
OBD1 PR4
The OBD1 version utilizes the standard three-plug connector layout introduced in 1992. It features updated internal components to support the more advanced OBD1 diagnostic and emissions requirements.
Related Documentation
For detailed pinout configurations and component-level diagnostics, refer to the specific variant pages: