Experiencing a “No Communication” error when you plug your OBD2 scanner into your 2010 Chevy Suburban can be incredibly frustrating. This issue prevents you from reading diagnostic trouble codes (DTCs), checking your vehicle’s health, and potentially diagnosing problems yourself. If you’re facing this problem, you’re not alone. Many 2010 Suburban owners encounter this frustrating scenario. Let’s explore some troubleshooting steps you can take to pinpoint the cause and hopefully get your OBD2 port communicating again.
Initial Checks: Fuse and OBD2 Port
The most straightforward place to start is with the basics. A common culprit for a non-functional OBD2 port is a blown fuse. As the original poster mentioned, checking the fuses is a smart first step.
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Fuse Check: Locate the fuse box in your Chevy Suburban. Typically, in a Suburban of this year, you’ll find fuse boxes under the hood and sometimes on the driver’s side interior panel or in the rear cargo area. Consult your owner’s manual to identify the fuse specifically related to the Data Link Connector (DLC) or OBD2 port. Visually inspect the fuse to see if the filament is broken. Even better, use a multimeter to test for continuity across the fuse terminals to be absolutely sure it’s good. Replace any blown fuses with a fuse of the same amperage.
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OBD2 Port Inspection: Take a close look at the OBD2 port itself, usually located under the dashboard on the driver’s side. Check for any signs of physical damage, bent pins, or corrosion. Since the original poster mentioned their vehicle is from Florida and corrosion is unlikely, this might be less of a concern, but it’s always good to visually inspect. Make sure nothing is obstructing the port that could prevent your scanner from making a good connection.
Advanced Diagnostics: BCM and Ignition Switch
If the fuse is good and the OBD2 port looks okay, the problem might be a bit deeper. The original forum post dives into testing the Body Control Module (BCM) and ignition switch, which are crucial components for OBD2 communication. Let’s analyze these steps further.
The forum excerpt discusses voltage readings on specific pins of the BCM connector (C2, pins 62 and 56). These pins are related to the ignition switch signal and the 5V reference voltage, both essential for the BCM to function correctly and enable OBD2 communication.
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BCM Voltage Tests (Advanced – Use a Multimeter): Caution: Working with electrical systems requires caution. If you’re not comfortable with electrical testing, it’s best to consult a qualified technician. The original poster performed voltage checks on BCM connector C2, pins 62 and 56. These readings are valuable for diagnosing potential issues with the ignition switch circuit and BCM power supply.
- Pin 62 (Reference Voltage): According to the forum, pin 62 should have +5V with the key OFF, indicating a constant reference voltage supply to the ignition switch. The original poster recorded readings close to 5V in different key positions, which seems normal for this pin.
- Pin 56 (Ignition Switch Signal): Pin 56 is the signal return from the ignition switch to the BCM. The expected behavior is:
- Key OFF: 0V
- Key RUN: ~+5V
- Key START: ~1.5-2.5V
The original poster’s readings on pin 56 were slightly different from the “ideal” values mentioned in the forum but still showed voltage changes in different key positions. This indicates the ignition switch is sending signals to the BCM, but the voltage levels might be slightly off, or there could be other issues.
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Ignition Switch Resistance Test (Advanced – Battery Disconnect Required): The forum also describes a resistance test for the ignition switch. This test helps verify the continuity and resistance of the ignition switch circuits.
- Safety First: Disconnect the battery before performing this test to prevent electrical damage.
- Disconnect BCM Connector C2.
- Set your multimeter to measure resistance (Ohms).
- Connect multimeter leads to connector C2 pins 56 and 61 (or 62 as tested by the original poster due to pin availability).
- Test in different ignition switch positions:
- Key OFF: Open circuit (infinite resistance)
- Key ON: Continuity (low resistance)
- Key START: A few Kilo-Ohms resistance (as indicated in the forum excerpt)
The original poster performed a similar test using pin 62 instead of 61 (due to pin availability) and reported that the test “checked out.” This suggests the ignition switch itself might be functioning, but the issue could still lie in the wiring or the BCM itself.
Further Troubleshooting and Potential Causes
If the fuse, OBD2 port, ignition switch, and BCM voltage readings seem within expected ranges, but you still have no OBD2 communication, consider these additional possibilities:
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Wiring Issues: There could be a break, short, or corrosion in the wiring between the OBD2 port, BCM, ECM (Engine Control Module), and other relevant modules. Inspect the wiring harness for any visible damage. A wiring diagram for your 2010 Suburban would be extremely helpful in tracing the circuits involved in OBD2 communication.
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OBD2 Port Internal Problems: While you visually inspected the port, there could be internal damage you can’t see. Sometimes, the pins inside the port can lose their springiness or become internally disconnected. In rare cases, the OBD2 port itself might need replacement.
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BCM or ECM Failure: Although less common, a faulty BCM or ECM can also cause a “No Communication” issue. The original poster mentioned Charlie Gates replacing “ECMs” in a similar Cobalt case, suggesting module failure is a possibility, albeit often a last resort diagnosis.
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CAN Bus Issues: OBD2 communication relies on the Controller Area Network (CAN) bus system. Problems with the CAN bus, such as a faulty module on the network disrupting communication, can also lead to a “No Communication” error. Diagnosing CAN bus issues often requires specialized tools and knowledge.
Conclusion and Next Steps
Troubleshooting a “No Communication with OBD2” issue on your 2010 Chevy Suburban requires a systematic approach. Start with the simple checks like fuses and the OBD2 port itself. If those are ruled out, more advanced diagnostics like BCM voltage testing and ignition switch resistance checks can help narrow down the problem.
If you’ve gone through these steps and are still facing the issue, it’s highly recommended to seek professional help from a qualified automotive technician. They have specialized diagnostic tools, wiring diagrams, and expertise to further pinpoint the root cause, which could range from wiring problems to module failures. Don’t hesitate to get professional assistance to resolve this frustrating OBD2 communication problem and get your Suburban back to its optimal working condition.
