DTC C1377/43: Capacitor Malfunction: Procedure

1. Check the INF code from the Freeze Frame Data memorized when the DTC (C1377/43) was stored, refer to FREEZE FRAME DATA .

   Result

   Result	Proceed to
   INF codes 109 and/or 110 are output	A
   INF codes 101, 102, 105, 106 and/or 108 are output	B
   INF code 103 is output	C

B → See step   12 

C → See step   8 

A: Go to next step 

1. Remove the CAPACITER fuse from the engine room relay block.
   Fig 1: Identifying Capaciter Fuse

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   CAPACITER (15 A) fuse	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Engine Room Relay Block
   *2	CAPACITER Fuse

NG → REPLACE CAPACITER FUSE 

OK: Go to next step 

1. Install the CAPACITER fuse.
   Fig 2: Identifying Brake Control Power Supply Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the brake control power supply connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   O40-8 (+BC) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Brake Control Power Supply)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT) 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 3: Identifying Brake Control Power Supply Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O40-14 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Brake Control Power Supply)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

OK: Go to next step 

1. Reconnect the brake control power supply connector.
   Fig 4: Identifying Brake Control Power Supply Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   O40-1 (OUT1) - Body ground	Ignition switch ON	11 to 14 V
   O40-7 (OUT2) - Body ground	Ignition switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Brake Control Power Supply)

NG → See step   12 

OK: Go to next step 

Fig 5: Identifying Skid Control ECU Connectors

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Turn the ignition switch to ON.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A44-7 (CBI1) - Body ground	Ignition switch ON	8.8 to 14 V
   A47-2 (CBI2) - Body ground	Ignition switch ON	8.8 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Component with harness connected (Skid Control ECU)

NG → See step   13 

OK: Go to next step 

1. Turn the ignition switch off.
2. Clear the DTCs, refer to DTC CHECK / CLEAR .
3. Turn the ignition switch to ON.
4. Check if the same DTC is recorded, refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC (C1377/43) is not output	A
   DTC (C1377/43) is output	B

B → See step   13 

A → See step   11 

1. Check the auxiliary battery voltage.

   Standard Voltage

   11 to 14 V

NG → CHARGE OR REPLACE AUXILIARY BATTERY 

OK: Go to next step 

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
   Fig 6: Identifying Brake Control Power Supply Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the brake control power supply connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   O40-8 (+BC) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Brake Control Power Supply)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT) 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 7: Identifying Brake Control Power Supply Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O40-14 (GND) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to Brake Control Power Supply)

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT) 

OK → See step   12