The 1994 S10 Blazer, like other GM vehicles from this era, presents a unique challenge when it comes to onboard diagnostics. While equipped with an OBD2-style connector, it doesn’t quite adhere to OBD2 standards. This article clarifies the complexities of the 1994 S10 Blazer’s OBD system.
This “in-between” system, sometimes referred to as OBD1.5, necessitates specific diagnostic tools. Unlike true OBD1 systems (identifiable by the Assembly Line Diagnostic Link (ALDL) connector under the dash), which allow code retrieval with a simple paperclip,
and unlike true OBD2 systems, which work with standard OBD2 scanners, the 1994 S10 Blazer requires specialized equipment. Common misconceptions link PCM location (on the coolant reservoir), distributor cap design (horizontal wires), or even the presence of an OBD2-style connector to OBD2 compliance. However, these are not reliable indicators.
A 1995 Jimmy, for instance, with the PCM under the hood, horizontal distributor cap wires, and an OBD2 connector, is confirmed OBD1 by its underhood sticker. This highlights the importance of accurate information.
Practical experience shows that tools like the Actron CP9150 (available online) or professional-grade scanners with appropriate software can effectively diagnose these 94-95 GM vehicles. If a standard OBD2 scanner doesn’t work, the vehicle is not truly OBD2 compliant. This 1995 Jimmy, with pre and post catalytic converter oxygen sensors and a crank sensor, lacks EVAP monitoring capabilities, further differentiating it from a full OBD2 system.
It’s important to note that some 94-95 S10 Blazers utilized TBI (Throttle Body Injection) with a more traditional “vertical TB” air cleaner setup, resembling a carburetor engine. These models likely retained the older OBD1 ALDL system.
Understanding these nuances is crucial for anyone working on a 1994 S10 Blazer. Correctly identifying the diagnostic system ensures accurate troubleshooting and repairs. Remember, the presence of an OBD2-style connector doesn’t guarantee OBD2 functionality in these transitional-year vehicles. Always verify compatibility before investing in diagnostic tools.
