Dashboard light problem, codes B2502, B2500 and B1493

B1493 - Occupant Classification System Communication Error
B2500 - Airbag Warning General Failure
B2502 - Airbag Telltale Lamp Failure


These codes are telling you that you have a wiring issue or module issue in the communication harness for the airbag system. This is a very sensitive system and I would highly recommend taking this to a dealership if you are not comfortable diagnosing wiring and airbag systems. The reason I say that is trying to diagnose and airbag issue you could inadvertently cause the airbags to deploy.

If you are comfortable then I attached the testing that we need to do. We need to focus on the B1493 code as they other 2 are only informational.

However, once we get past the initial inspection of the wiring we get into needing CAN communication tools to monitor and inspect the wiring properly. Then we need a scan tool shown in the testing. Unfortunately to properly diagnose this we need those tools because they don't give a way to test the airbags with meters or more common electrical tools. They did this so that it is hard for non dealers/shops to work on this system.

Run through this and let me know what questions you have.

This doesn't sound good and I certainly won't be able to diagnose this myself. Is the SRS module located under the front passenger seat? I can likely at least disconnect the battery, inspect, and clean the SRS module contacts.

What are some potential reasons/fixes for this? Poor wiring condition? Replacement of the SRS wiring or module required? Any idea of potential cost range?

This B1493 code doesn't sound promising. I had another electronic issue that a shop sorted out regarding poor ECM connection - code C1611. Wiring connectors just needed cleaning up thankfully. Nearly all wiring connectors in the engine bay were cleaned and inspected.

So this is a communication error which is usually a wiring issue/connection issue. You are correct that these are not easy and frankly many of them don't get diagnosed correctly by trained mechanics.

The module is actually under the center console. However, you need to be very careful with this and as you said you need to disconnect the battery before you even access it. This has rollover valves in it and are sensitive. I have seen guys get hit with airbags when they remove this and forget to disconnect the battery or reconnect the battery and forget that they have it unbolted and sitting crocked. Also, guys have used an air tool to remove the bolts and the vibration will set off the airbags if the battery is not disconnected.

Let me know how you make out.

All fixed! Car only needed a new battery.

Unbelievable. I have been burned by this so many times that lately I have been advising everyone with electrical issues to just start with getting the battery checked. Obviously the one that I don't mention this to, turns out to just be a battery.

So glad you got it resolved and thanks so much for coming back to update us as that will surely help others.

Thanks