The Toyota Code C1391/69 is an accumulator leak malfunction code that is issued when either of the following is detected: an accumulator pressure sensor input that does not increase before braking or while the pump motor is operating, or an accumulator pressure sensor input reduction rate that exceeds the specification before braking and while the pump motor is not operating. This malfunction can be caused by a variety of issues such as brake fluid leaks and malfunctioning internal seals, low gas pressure in the accumulator, and more. To help those affected by the Toyota Code C1391/69, below is a table outlining the causes and possible solutions.
Causes and Solutions for Toyota Code C1391/69
| Cause | Solution |
|---|---|
| Brake fluid leaks | Replace the leaking brake fluid parts and replace the brake fluid. |
| Malfunctioning internal seal, low gas pressure in accumulator, etc. | Replace the brake booster with a new master cylinder (Brake actuator). |
| Insufficient power supply to the pump motor | Check the power supply system, and repair or replace the malfunctioning power supply parts. |
| Malfunction of the hydraulic control circuit | Check the hydraulic control circuit and repair or replace the malfunctioning parts. |
Brake Fluid Leaks
The most common cause of the Toyota Code C1391/69 is a brake fluid leak. Brake fluid leaks can be caused by a variety of factors, such as a worn out or malfunctioning seal or an insufficiently tight connection. In order to address this issue, the leaking brake fluid parts must be replaced, and the brake fluid must be refilled.
Malfunctioning Internal Seal, Low Gas Pressure in Accumulator, etc.
Another cause of the Toyota Code C1391/69 is a malfunctioning internal seal or low gas pressure in the accumulator. This can cause the accumulator pressure sensor input to not increase before braking or while the pump motor is operating. If this is the case, the brake booster must be replaced with a new master cylinder (Brake actuator).
Insufficient Power Supply to the Pump Motor
Insufficient power supply to the pump motor is another cause of the Toyota Code C1391/69. If this is the case, the power supply system must be checked and any malfunctioning power supply parts must be repaired or replaced.
Malfunction of the Hydraulic Control Circuit
A malfunction of the hydraulic control circuit can also be the cause of the Toyota Code C1391/69. If this is the case, the hydraulic control circuit must be checked, and any malfunctioning parts must be repaired or replaced.
Conclusion
The Toyota Code C1391/69 is an accumulator leak malfunction code that can be caused by a variety of issues such as brake fluid leaks, malfunctioning internal seals, low gas pressure in the accumulator, insufficient power supply to the pump motor, and a malfunction of the hydraulic control circuit. If you are experiencing this issue, the solutions listed in the table above should help you address the problem.
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