Diagnostic Procedure
WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.
DTC B1258:4B [DASH-ELECTRICAL SUPPLY UNIT] DIAGNOSTIC PROCEDURE
| Step | Inspection | Results | Action |
|---|---|---|---|
| 1 | VERIFY IF REAR VENT ACTUATOR TEMPERATURE WAS TEMPORARILY HIGH
|
Yes | Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW (US) .) If the CAN communication is normal, replace malfunctioning location and perform the repair completion verification. (See REAR VENT ACTUATOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) |
| No | Go to repair completion verification 2. | ||
| Repair completion verification 1 | VERIFY THAT VEHICLE IS REPAIRED
|
Yes | Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW (US) .) If the CAN communication is normal, perform the diagnosis from Step 1.
|
| No | Go to the next step. | ||
| Repair completion verification 2 | VERIFY IF OTHER DTCs DISPLAYED
|
Yes | Repair the malfunctioning location according to the applicable DTC troubleshooting. |
| No | DTC troubleshooting completed. |