The 1995 Chevy Blazer, like other GM vehicles from this era, presents a confusing situation regarding its OBD system. While it features an OBD2-style connector, it doesn’t necessarily mean it’s fully OBD2 compliant. Let’s explore this further.
The 94-95 GM OBD Transition: OBD1.5?
In 1994 and 1995, General Motors initiated a transition towards the OBD2 system. However, this period saw a hybrid system often referred to as OBD1.5. This means that although a 95 Blazer has a 16-pin OBD2 connector located under the dashboard, standard OBD2 scanners often won’t work.
This connector, visually identical to the OBD2 port, requires a specialized scanner designed for 1994-95 GM vehicles. This is because the communication protocols and diagnostic trouble codes (DTCs) used are different from the standardized OBD2 system implemented in later models.
Identifying Features: Don’t Rely on Myths
Several misconceptions exist regarding identifying the OBD system in these vehicles:
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PCM Location: Some believe the Powertrain Control Module (PCM) location indicates the OBD system. While some 95 Blazers have the PCM on the coolant reservoir, this isn’t a definitive indicator of OBD2 compliance.
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Distributor Cap: Another myth connects horizontal distributor cap wires to OBD2. Again, this is not a reliable indicator.
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Underhood Sticker: Even if a sticker under the hood states “OBD1 Certified,” the presence of the 16-pin connector still indicates the transitional OBD system.
The most accurate way to determine compatibility is to try a known working OBD2 scanner. Failure to connect confirms the need for a specialized 94-95 GM compatible tool.
Scanner Options for a 95 Blazer
Owners of 95 Blazers will need a scanner specifically designed for this transitional OBD system. Options include:
- Specialized Scanners: Tools like the Actron CP9150 (or similar models) are designed to communicate with the 94-95 GM systems.
- Professional Scanners: High-end professional automotive scanners (e.g., Snap-on) with the correct software can also diagnose these vehicles.
OBD1 vs. OBD1.5: Key Differences
While the 95 Blazer utilizes a 16-pin connector, it’s crucial to understand the differences from true OBD2:
- Communication Protocols: OBD1.5 employs different communication protocols than OBD2.
- Diagnostic Trouble Codes: The DTCs generated by the 1995 Blazer system are not standardized OBD2 codes.
Conclusion: Yes, But…
A 1995 Chevy Blazer does have an OBD2-style port. However, it’s essential to understand that this port doesn’t function with standard OBD2 scanners. Due to the transitional OBD system employed in these vehicles, a specialized scanner compatible with 1994-95 GM vehicles is required for diagnostics. Don’t let the appearance of the connector fool you; always confirm compatibility before purchasing a diagnostic tool.
