Toyota Tundra Service Manual: Output Circuit Temperature High / Over Current (C14A4,C14A6,C14AA)

Toyota Tundra Service Manual / Brake / Brake Control / Dynamic Control Systems / Trailer Brake Control System / Output Circuit Temperature High / Over Current (C14A4,C14A6,C14AA)

DESCRIPTION

The trailer brake control ECU (brake control with bracket relay) is connected via the trailer socket and direct line.

The trailer brake control ECU (brake control with bracket relay) outputs a signal to the trailer socket.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

C14A4

Output Circuit Temperature High / Over Current

-

With the ignition switch on and the IG terminal voltage from 11 to 14 V, the trailer brake control ECU (brake control with bracket relay) output circuit current value continuously exceeds 27.8 to 40 A for 1 second or more

  • Harness or connector (Vehicle)
  • Harness or connector (Trailer)
  • Trailer brake control ECU (Brake control with bracket relay)

C14A6

Output Circuit Negative Voltage

61

62

  • INF Code: 61
    • With the ignition switch on and the IG terminal voltage from 11 to 14 V, an open circuit occurs in the trailer brake control ECU (brake control with bracket relay) output circuit for 1.9 seconds or more
  • INF Code: 62
    • With the ignition switch on, the IG terminal voltage from 11 to 14 V and the trailer brake control ECU (brake control with bracket relay) not performing control, a voltage of 3.2 to 3.8 V or more is input to the trailer brake control ECU (brake control with bracket relay) output circuit
  • Harness or connector (Vehicle)
  • Harness or connector (Trailer)
  • Trailer brake control ECU (Brake control with bracket relay)

C14AA

ECU Malfunction(FET High Temperature)

-

Any of the following is detected:

  • With the ignition switch on and the IG terminal voltage from 11 to 14 V, the trailer brake control ECU (brake control with bracket relay) output circuit temperature continuously exceeds 160°C for 1 second or more
  • With the ignition switch on and the IG terminal voltage from 11 to 14 V, the trailer brake control ECU (brake control with bracket relay) output circuit current value continuously exceeds 50 A for 1 second or more
  • With the ignition switch on and the IG terminal voltage from 11 to 14 V, the trailer brake control ECU (brake control with bracket relay) output circuit current value continuously exceeds 100 A for 1 second or more
  • Harness or connector (Vehicle)
  • Harness or connector (Trailer)
  • Trailer brake control ECU (Brake control with bracket relay)

WIRING DIAGRAM

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (BRAKE CONTROL WITH BRACKET RELAY - TRAILER SOCKET)

(a) Turn the ignition switch off.

(b) Disconnect the J172 trailer brake control ECU (brake control with bracket relay) connector.

(c) Inspect both the connector case and the terminal for deformation and corrosion.

OK:

No deformation or corrosion.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J172-1 (BRK) - R18-6 (BRK)

Always

Below 1 Ω

J172-1 (BRK) - R18-6 (BRK) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (VEHICLE)

OK

2.

CHECK TERMINAL VOLTAGE (BRK TERMINAL)

(a) Connect the J172 trailer brake control ECU (brake control with bracket relay) connector.

*a

Front view of wire harness connector

(to Trailer Brake Control ECU (Brake Control with Bracket Relay))

(b) Inspect both the connector case and the terminal for deformation and corrosion.

OK:

No deformation or corrosion.

(c) Turn the ignition switch to ON.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

R18-6 (BRK) - Body ground

  • Ignition switch ON
  • No trailer brake control

Below 3.5 V

NG

GO TO STEP 6

OK

3.

CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Turn the ignition switch off.

(b) Disconnect the J172 trailer brake control ECU (brake control with bracket relay) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

J172-20 (GND) - Body ground

Always

Below 1 Ω

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (VEHICLE)

OK

4.

CHECK HARNESS AND CONNECTOR (GND TERMINAL)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

R18-3 (GND) - Body ground

Always

Below 1 Ω

*a

Front view of wire harness connector

(to Trailer Brake Control ECU (Brake Control with Bracket Relay))

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (VEHICLE)

OK

5.

CHECK TERMINAL VOLTAGE (IG TERMINAL)

(a) Check the wire harness and connector of the connected trailer.

Check items
  • Connector link state
  • Connector looseness or disconnection
  • Deformation and corrosion of connector case and terminal
  • Standard voltage and resistance of wire harness and connector (refer to manual of each trailer for standard values)

OK:

No problem with check items.

OK

REPLACE BRAKE CONTROL WITH BRACKET RELAY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (TRAILER)

6.

CHECK TERMINAL VOLTAGE (BRK TERMINAL)

(a) Turn the ignition switch off.

(b) Disconnect the J172 trailer brake control ECU (brake control with bracket relay) connector.

*a

Front view of wire harness connector

(to Trailer Brake Control ECU (Brake Control with Bracket Relay))

(c) Turn the ignition switch to ON.

(d) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

R18-6 (BRK) - Body ground

Ignition switch ON

Below 3.5 V

HINT:

Before replacing the trailer brake control ECU (brake control with bracket relay), check that there are no malfunctions (GND short) in the trailer side circuit.

OK

REPLACE BRAKE CONTROL WITH BRACKET RELAY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (VEHICLE)

    Gain Rocker Switch (+) Circuit (C14A1,C14A2)

    ECU Malfunction (C14A7)

    See More:

    Toyota Tundra Service Manual > Front Lower Suspension Arm: Inspection
    INSPECTION PROCEDURE 1. INSPECT FRONT NO. 1 SUSPENSION ARM LOWER SUB-ASSEMBLY LH (a) As shown in the illustration, move the ball joint stud back and forth 5 times before installing the nut. (b) Using a torque wrench, turn the nut continuously at a rate of 3 to 5 seconds per turn and take the torque ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2021 Copyright www.ttundra.com
    0.0175