C1378 Toyota Code - Capacitor Communication Circuit Malfunction
Quick Answer
The Brake Control Power Supply Assembly (Capacitor) provides auxiliary power for brake control when an auxiliary battery (12 V) voltage drops. Common causes include Faulty Skid Control ECU, Skid Control ECU harness is open or shorted, Skid Control ECU circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- C1378 Toyota indicates Capacitor Communication Circuit Malfunction.
- Common causes
- Common causes include Faulty Skid Control ECU, Skid Control ECU harness is open or shorted, Skid Control ECU circuit poor electrical connection.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
Code C1378 Toyota Description
What are the Possible Causes of the DTC C1378 Toyota?
- Faulty Skid Control ECU
- Skid Control ECU harness is open or shorted
- Skid Control ECU circuit poor electrical connection
How to Fix the DTC C1378 Toyota?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the C1378 Toyota code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about C1378 Toyota Code
1. What does the OBDII code C1378 mean on a Toyota?
C1378 indicates a "Capacitor Communication Circuit Malfunction," which typically involves an issue with the capacitor circuit in the brake booster system.
2. What are the common symptoms of a C1378 code on a Toyota?
Symptoms may include illuminated warning lights such as the ABS or brake warning light, reduced braking performance, and possibly a failure of the regenerative braking system in hybrid models.
3. What causes the C1378 code to appear on a Toyota?
Common causes include a faulty capacitor, damaged wiring or connectors in the capacitor communication circuit, or a malfunctioning brake booster assembly.
4. Can a weak or dead 12V battery trigger the C1378 code?
Yes, a weak or dead 12V battery can affect the capacitor circuit's communication and potentially trigger the C1378 code.
5. How do I diagnose the C1378 code on my Toyota?
Start by inspecting the capacitor circuit wiring and connectors for damage or corrosion. Check the brake booster assembly and test the capacitor for faults using a multimeter.
6. Can I drive my Toyota with a C1378 code?
Driving with a C1378 code is not recommended, as it may result in compromised braking performance, which could be unsafe.
7. How is the C1378 code repaired on a Toyota?
Repairs may involve replacing the faulty capacitor, repairing or replacing damaged wiring or connectors, or replacing the brake booster assembly if necessary.
8. Is the C1378 code common in Toyota hybrid vehicles?
Yes, the C1378 code is more commonly associated with Toyota hybrid models due to their regenerative braking systems, which rely on the capacitor circuit.
9. How much does it cost to fix a C1378 code on a Toyota?
Repair costs vary depending on the root cause but could range from $200 to $1,200, depending on whether the capacitor or brake booster assembly needs replacement.
10. Can clearing the C1378 code solve the problem?
Clearing the code without addressing the root cause will not fix the issue. The code will likely reappear until the underlying problem is resolved.
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