Toyota Tundra Service Manual: ECU Power Source Circuit Malfunction (B2620)

DESCRIPTION

The ECU power source circuit supplies positive (+) voltage to the multiplex tilt and telescopic ECU.

DTC Code	Detection Condition	Trouble Area
B2620	The voltage of the ECU power source drops to 8 V or less and this condition continues for 10 seconds or more.	ECU-DCC NO. 2 fuse Harness or connector Multiplex tilt and telescopic ECU

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (MULTIPLEX TILT AND TELESCOPIC ECU - BATTERY)

(a) Disconnect the J174 multiplex tilt and telescopic ECU connector.

*a	Front view of wire harness connector (to Multiplex Tilt and Telescopic ECU)

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
J174-9 (ECUB) - Body ground	Always	11 to 14 V

REPAIR OR REPLACE HARNESS OR CONNECTOR

2.	CHECK HARNESS AND CONNECTOR (MULTIPLEX TILT AND TELESCOPIC ECU - BODY GROUND)

(a) Disconnect the J174 multiplex tilt and telescopic ECU connector.

*a	Front view of wire harness connector (to Multiplex Tilt and Telescopic ECU)

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
J174-8 (GND2) - Body ground	Always	Below 1 Ω

REPLACE MULTIPLEX TILT AND TELESCOPIC ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

Toyota Tundra Service Manual > Automatic Transmission System: Shift Solenoid "D" Performance (Shift Solenoid Valve S4) (P0766,P0776)
DESCRIPTION The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th, 5th or 6th gear). Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid val ...

Toyota Tundra Owners Manual