DTC C1378: Capacitor Communication Malfunction [10/2020 - 10/2023]: Description
The brake control power supply with bracket assembly provides auxiliary power for brake control when the auxiliary battery (12 V) voltage drops.
The FAIL and ENA lines are placed between the skid control ECU assembly and the brake control power supply with bracket assembly.
Signals indicating that the brake control power supply with bracket assembly is in auxiliary mode are sent to the skid control ECU assembly through the FAIL line.
Charge permit prohibition signals are sent to the brake control power supply with bracket assembly through the ENA line.
| DTC No. | Detection Item | INF Code | DTC Detection Condition | Trouble Area | MIL | Note |
|---|---|---|---|---|---|---|
| C1378 | Capacitor Communication Malfunction | 112 | Any of the following is detected
|
|
Does not come on | - |
DTC DETECTION CONDITIONS: C1378 INF CODE: 112
| Vehicle Condition | |||||
|---|---|---|---|---|---|
| Pattern 1 | Pattern 2 | Pattern 3 | Pattern 4 | ||
| Diagnosis Condition | IG1 terminal voltage is 9.5 V or more | - | - | ◦ | ◦ |
| Malfunction Status | Open or short in FAIL line | ◦ | - | - | - |
| Malfunction inside the power back up unit | - | ◦ | - | - | |
| A malfunction signal is received from the brake control power supply with bracket assembly | - | - | ◦ | - | |
| Communication from the brake control power supply with bracket assembly is invalid (normal signals, capacitor mode signals or malfunction signals cannot be received) | - | - | - | ◦ | |
| Detection Time | - | - | 12 seconds or more | 12 seconds or more | |
| Number of Trips | 1 trip | 1 trip | 1 trip | 1 trip | |