Trailer Brake Control System

2025 Toyota 4Runner SR5, RWDSECTION Trailer Brake Control System
TRAILER BRAKE CONTROL SYSTEM DIAGNOSTIC TROUBLE CODE (DTC) IDENTIFICATION

DTC Code Description
C1020-16 IGR Circuit Circuit Voltage Below Threshold
C1020-17 IGR Circuit Circuit Voltage Above Threshold
C105F-62 IGR Voltage / Actuator Supply Voltage Signal Compare Failure
C1150-12 Trailer Brake Manual Slider Position Sensor Circuit Circuit Short to Battery
C1150-14 Trailer Brake Manual Slider Position Sensor Circuit Circuit Short to Ground or Open
C1150-28 Trailer Brake Manual Slider Position Sensor Circuit Signal Bias Level Out of Range / Zero Adjustment Failure
C1150-62 Trailer Brake Manual Slider Position Sensor Circuit Signal Compare Failure
C1154-9E Trailer Brake Gain (+) Switch Stuck On
C1155-9E Trailer Brake Gain (-) Switch Stuck On
C1156-04 MCU System Internal Failure
C1157-13 Trailer Detection Circuit Circuit Open
C1158-72 Power Relay Actuator Stuck Open
C1158-73 Power Relay Actuator Stuck Closed
C115A-11 Output Circuit Short to GND Circuit Short to Ground
C115A-15 Output Circuit Short to Battery Circuit Short to Battery or Open
C115A-49 Pre-Driver Internal Electronic Failure
C115E-00 Functional Safety Failure (Predetermined Maximum Output Exceeded)
C115E-19 Output Circuit Over Current Circuit Current Above Threshold
C115E-94 Functional Safety Failure (Unintended Braking) Unexpected Operation
U0076-88 Control Module Communication Bus "D" Off Bus Off
U0077-88 Control Module Communication Bus "E" Off Bus Off
U0078-88 Control Module Communication Bus "F" Off Bus Off
U0129-87 Lost Communication with Brake System Control Module "A" Missing Message
U0155-87 Lost Communication with Instrument Panel Cluster (IPC) Control Module Missing Message
U1170-87 Lost Communication with Brake System Control Module (ch2) Missing Message
U1171-87 Lost Communication with Brake System Control Module (ch3) Missing Message
RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.