The C1391 diagnostic trouble code (DTC) is a common issue for 2011-2013 Toyota Highlander Hybrid models. This code, often accompanied by illuminated brake, ABS, and TRAC warning lights and a “Check VSC” message, indicates a potential problem with the brake actuator. This article outlines the causes, symptoms, and solutions related to the C1391 code in Toyota Highlander Hybrid vehicles.
Understanding the C1391 Code in Highlander Hybrids
The C1391 DTC specifically points to an internal brake fluid leak within the brake actuator assembly. This leak can disrupt the normal functioning of the braking system, leading to safety concerns. Other related DTCs, such as C1252, C1253, and C1256, might also be stored in the vehicle’s memory, further indicating a problem within the brake system.
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Diagnosing the Problem
If your Highlander Hybrid displays warning lights or the “Check VSC” message, a diagnostic scan using a professional tool like Techstream is crucial. This scan will reveal any stored DTCs, confirming whether the C1391 code or related codes are present. If these codes are identified, the issue likely lies within the brake actuator.
Repairing the C1391 Issue
The primary solution for a C1391 code caused by an internal brake fluid leak is to replace the entire brake actuator and booster pump assembly. This process requires specialized tools and knowledge, and is best performed by a qualified Toyota technician. After the replacement, any stored DTCs should be cleared using Techstream, followed by a thorough test drive to confirm the issue is resolved.
Toyota Warranty Coverage for C1391
Toyota has recognized this issue and offers warranty coverage for the brake actuator replacement under specific conditions. This repair falls under the Toyota Basic Warranty, which typically covers 36 months or 36,000 miles, whichever comes first. However, it’s essential to verify eligibility with a Toyota dealership, as coverage may vary based on the vehicle’s history and specific circumstances. Furthermore, this issue may be covered under an extended warranty program, specifically CUSTOMER SUPPORT PROGRAM 21TE03. Refer to T-SB-0097-21 for further details.
Conclusion
The C1391 DTC in a Toyota Highlander Hybrid signals a potentially serious brake system problem. Prompt diagnosis and repair are crucial to ensure vehicle safety. Consulting a Toyota dealership for diagnosis and repair is highly recommended. They can confirm the issue, perform the necessary repairs, and advise on warranty coverage for the brake actuator replacement.
