Lost Communication With OBD Diagnostic Module
The U0261 code means the vehicle's onboard diagnostic system has detected: Lost Communication With OBD Diagnostic Module. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- hard
- Estimated cost
- $150 - $600 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Scanner cannot communicate with vehicle
- No data from OBD-II port
- Check engine light on but no codes retrievable
- Emission test failure due to no communication
Probable Causes (Ranked by Likelihood)
- Failed OBD gateway module Very High
- Damaged OBD-II port connector High
- CAN bus wiring fault at OBD port Moderate
- Aftermarket device interfering with OBD Low
Step-by-Step Diagnostic Procedure
-
Remove any aftermarket OBD devices
-
Inspect OBD-II port pins for damage
-
Test CAN bus signals at OBD port
-
Check OBD gateway module power and ground
Frequently Asked Questions
Can I drive with U0261?
Yes, but you cannot read diagnostic codes or pass emissions testing.
What causes U0261?
Often an aftermarket OBD device causing interference. Damaged port pins are also common.
How do I fix U0261?
Remove any plug-in OBD devices first. If that does not help, inspect the port pins and wiring.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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