Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000001RNJ1
Model Year Start: 2021 Model: RAV4 Prod Date Range: [08/2020 - 12/2021]
Title: STOP AND START: STOP AND START SYSTEM: STA Signal Circuit; 2021 MY RAV4 [08/2020 - 12/2021]

STA Signal Circuit

DESCRIPTION

While the engine is being cranked, a starter operation request signal is sent to terminal STA of the ECM.

HINT:

If there is an open in the STA circuit of the ECM, stop and start control will be prohibited after the third time the engine is started by stop and start control.

  • Stop and start control will be prohibited until the ignition switch is turned off.
  • The MIL will not illuminate.
  • If there is an open in the STA circuit of the ECM, the engine can still be started using the ignition or starter switch assembly (w/o Smart Key System) or push start switch assembly (w/ Smart Key System), as the ECM also receives the starter operation request signal from the engine stop and start ECU via CAN communication. (Stop and start control is prohibited as the reliability of the signal sent via CAN communication cannot be assured while the voltage drops during operation of the starter assembly.)

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM (STARTER SW)

(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 SW.

Powertrain > Engine > Data List

Tester Display

Starter SW

(e) Read the values displayed on the Techstream when the ignition switch is ON and START.

OK:

Techstream Display

Condition

Normal Condition

Starter SW

Ignition switch ON

OFF

Ignition switch START

ON

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

CHECK HARNESS AND CONNECTOR (ECM - ST NO. 2 RELAY)

(a) Disconnect the ECM connector.

(b) Remove the ST NO. 2 relay from the No. 1 engine room relay block and No. 1 junction block assembly.

(c) Disconnect the engine stop and start ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A24-30 (STA) - 2 (ST NO. 2 relay)

Always

Below 1 Ω

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR