Experiencing issues with your OBD2 scanner not turning on when plugged into your 2001 Chevy Blazer can be frustrating. This article provides a troubleshooting guide to help you diagnose why your 2001 Blazer OBD2 port is not powering up, preventing you from reading diagnostic trouble codes and assessing your vehicle’s health.
The first step is to confirm power and ground to the Diagnostic Link Connector (DLC), which is essential for any OBD2 scanner to function. Pin 16 of the DLC should provide battery voltage, while pins 4 and 5 are ground. Using a multimeter, check for voltage between pin 16 and pins 4 or 5. A reading of around 12V indicates proper power and ground are present at the OBD2 port. If you’re not getting voltage, investigate the power supply to pin 16. This often involves checking fuses related to the cigarette lighter or auxiliary power, as they sometimes share circuits.
If power and ground are confirmed at the DLC, the issue might lie in the communication pathways. Continuity testing between DLC pin 2 (J1850 VPW bus) and the Powertrain Control Module (PCM) pin 59 is crucial to ensure data can flow. A break in this wire can prevent scanner communication.
Scanner compatibility is another factor. While OBD2 is standardized, some older vehicles, like the 2001 Blazer, might not be fully compatible with all modern, low-end scanners. Trying a different, potentially more advanced OBD2 scanner can help rule out scanner-specific issues. Sometimes, basic code readers might not be sufficient for older truck models.
In cases where basic checks are normal, a faulty PCM could be the culprit, although this is less common. Before considering PCM replacement, exhaust all other possibilities, including thorough wiring inspections and trying different scan tools. Remember to methodically check each potential cause to effectively diagnose why your 2001 Blazer Obd2 Will Not Turn On and restore your diagnostic capabilities.
