When modifying your Honda, particularly when considering engine swaps or performance upgrades, understanding Engine Control Units (ECUs) is crucial. If you’re dealing with a D15B engine and an OBD2 system, the P28 ECU often comes into the conversation. Let’s clarify why and how the Obd2 P28 ECU plays a role in these scenarios.
Often, individuals with OBD2 (specifically OBD2A or OBD2B) vehicles might consider using a D15B engine. The stock ECU for a D15B engine is typically a P08, which is an OBD1 ECU designed for earlier Honda models. To properly run a D15B in an OBD2 car, you’ll generally need an OBD1 ECU. This is where the P28 ECU becomes relevant.
For a straightforward, stock D15B engine setup without future modifications or tuning needs, a P08 OBD1 ECU could suffice. However, the P28 OBD1 ECU is widely recommended, especially if you anticipate any performance upgrades or tuning in the future. The P28 is more versatile and offers better tuning capabilities compared to the stock P08.
To make an OBD1 ECU like the P28 work with your OBD2 vehicle, a conversion harness is essential. This harness acts as an adapter, bridging the wiring differences between the OBD2 system in your car and the OBD1 ECU.
Identifying whether your Honda is OBD2A or OBD2B is the first step in selecting the correct conversion harness. Visually, you can distinguish between OBD2A and OBD2B by examining the ECU connectors.
OBD2A ECUs are characterized by three ECU connectors positioned closely together.
In contrast, OBD2B ECUs have a noticeable space between the ECU connectors. To determine your ECU type, simply locate your ECU, unplug it, and compare the plug configuration to these diagrams. The configuration that matches your ECU plug will indicate whether you have an OBD2A or OBD2B system. This identification is critical for purchasing the correct OBD2 to OBD1 conversion harness.
For example, if you have a P2P ECU, which is an OBD2B ECU often found in models with Y8/Y8, VTEC engines, and you’re switching to a P28 (OBD1), you would need an OBD2B to OBD1 conversion harness.
Further research into resources like the Honda D engine Wikipedia page (http://en.wikipedia.org/wiki/Honda_D_engine) and websites like hondata.com can provide additional valuable information for your engine swap and ECU selection process.
In summary, when considering a D15B engine swap into an OBD2 Honda, opting for a P28 OBD1 ECU is a smart choice, especially for those planning future modifications. Remember to identify your OBD2 system type (A or B) to acquire the correct conversion harness for seamless integration.
