Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VIKJ
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 - 08/2016]
Title: U660E (AUTOMATIC TRANSMISSION / TRANSAXLE): AUTOMATIC TRANSAXLE SYSTEM: ECU Power Source Circuit; 2016 MY Sienna [12/2015 - 08/2016]

ECU Power Source Circuit

DESCRIPTION

When the ignition switch is turned to ON, voltage from the ECM MREL terminal is applied to the EFI MAIN relay. This causes the contacts of the EFI MAIN relay to close, which supplies power to terminal +B of the TCM.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (TCM - BODY GROUND)

(a) Turn the ignition switch off.

(b) Disconnect the TCM connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

B2-8 (E1) - Body ground

Always

Below 1 Ω

Text in Illustration

*a

Front view of wire harness connector

(to TCM)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.

INSPECT ECU TERMINAL VOLTAGE (+B TERMINAL)

(a) Disconnect the TCM connectors.

(b) Turn the ignition switch to ON.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

B2-18 (+B) - Body ground

Ignition switch ON

11 to 14 V

Text in Illustration

*a

Front view of wire harness connector

(to TCM)

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

3.

CHECK HARNESS AND CONNECTOR (TCM - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

(a) Turn the ignition switch off.

(b) Disconnect the TCM connector.

(c) Remove the EFI MAIN relay from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

B2-18 (+B) - EFI MAIN relay holder 3

Always

Below 1 Ω

B2-18 (+B) - Body ground

Always

10 kΩ or higher

OK

GO TO ECM POWER SOURCE CIRCUIT (ENGINE CONTROL SYSTEM / SFI SYSTEM)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR