DTC Logic
WARNING: This page is about a different car, the 2008 Infiniti M45 and 2008 Infiniti M35. However, it is still accessible from the selected car via links, so may be relevant.
DTC TROUBLE DETECTION TABLE
| DTC | Display contents of CONSULT-III | DTC Detection Condition | Action to take |
|---|---|---|---|
| U121F | INTERNAL COMM [U121F] | Malfunction is detected in AV control unit power supply and ground circuits. | Check AV control unit power supply and ground circuits. When detecting no malfunction in those components, replace AV control unit. |