Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM100000000VIB3
Model Year Start: 2016 Model: Sienna Prod Date Range: [12/2015 - 08/2016]
Title: 2GR-FE (ENGINE CONTROL): SFI SYSTEM: Cranking Holding Function Circuit; 2016 MY Sienna [12/2015 - 08/2016]

Cranking Holding Function Circuit

DESCRIPTION

The cranking holding control system keeps energizing the ST relay from when the power management control ECU detects the starter signal from the ignition switch assembly until the power management control ECU performs a judgement of "Engine started".

When the power management control ECU detects the STSW signal, the power management control ECU outputs the ST relay drive signal (STAR signal) to the ST relay through the park/neutral position switch, and then, the engine is cranked. When the power management control ECU receives a stable engine speed signal (NE signal), more specifically, when the NE signal reaches a predetermined value, the power management control ECU stops outputting the STAR signal.

Also, the power management control ECU monitors the ST relay operating conditions based on the STA terminal voltage status.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

1.

READ VALUE USING TECHSTREAM (STARTER SIGNAL)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine / Data List / Starter Signal.

(e) Check the result when the ignition switch is turned ON and the engine starts.

OK:

Condition

Starter Signal

Ignition switch ON

OFF

Engine start

ON

NG

GO TO STEP 5

OK

2.

CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ECM - ST RELAY)

(a) Remove the ST relay from the engine room relay block.

(b) Disconnect the park/neutral position switch connector.

(c) Disconnect the ECM connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

2 (ST relay holder) - A39-46 (STA)

Always

Below 1 Ω

2 (ST relay holder) - B3-9 (L)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A39-46 (STA) or B3-9 (L) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3.

INSPECT BATTERY

(a) Check that the battery is not depleted.

OK:

Battery is not depleted.

NG

REPLACE BATTERY

OK

4.

CHECK BATTERY TERMINAL

(a) Check that the battery terminals are not loose or corroded.

OK:

Battery terminals are not loose or corroded.

OK

REPAIR OR REPLACE STARTER CIRCUIT (STARTER ASSEMBLY - ST RELAY)

NG

REPAIR OR REPLACE BATTERY TERMINAL

5.

INSPECT PARK/NEUTRAL POSITION SWITCH (B - L)

(a) Inspect the park/neutral position switch (See page 2016 MY Sienna [12/2015 - 08/2016]; U660E (AUTOMATIC TRANSMISSION / TRANSAXLE): PARK / NEUTRAL POSITION SWITCH: INSPECTION for 2WD, 2016 MY Sienna [12/2015 - 08/2016]; U660F (AUTOMATIC TRANSMISSION / TRANSAXLE): PARK / NEUTRAL POSITION SWITCH: INSPECTION for AWD).

Result

Result

Proceed to

OK

A

NG

(for 2WD)

B

NG

(for AWD)

C

B

REPLACE PARK/NEUTRAL POSITION SWITCH (FOR 2WD)

C

REPLACE PARK/NEUTRAL POSITION SWITCH (FOR AWD)

A

6.

CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - PARK/NEUTRAL POSITION SWITCH)

(a) Disconnect the power management control ECU connector.

(b) Disconnect the park/neutral position switch connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

A35-3 (STAR) - B3-4 (B)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A35-3 (STAR) or B3-4 (B) - Body ground

Always

10 kΩ or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

7.

CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ECM - ST RELAY)

(a) Remove the ST relay from the engine room relay block.

(b) Disconnect the ECM connector.

(c) Disconnect the park/neutral position switch connector.

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

Standard Resistance (Check for Open):

Tester Connection

Condition

Specified Condition

2 (ST relay holder) - A39-46 (STA)

Always

Below 1 Ω

2 (ST relay holder) - B3-9 (L)

Always

Below 1 Ω

Standard Resistance (Check for Short):

Tester Connection

Condition

Specified Condition

A39-46 (STA) or B3-9 (L) - Body ground

Always

10 kΩ or higher

OK

CHECK SMART KEY SYSTEM

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR