Toyota Corolla Cross: 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 switch, 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 GTS (STARTER SW) |
(a) In accordance with the display on the GTS, read the Data List.
Powertrain > Engine > Data List|
Tester Display |
|---|
| Starter SW |
(b) Read the values displayed on the GTS when the ignition switch is ON and on (START).
OK:
|
GTS Display | Switch Condition |
Normal Condition |
|---|---|---|
|
Starter SW | Ignition switch ON |
OFF |
| Ignition switch START |
ON |
| OK | .gif) | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
|
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| 2. |
CHECK HARNESS AND CONNECTOR (ECM - ST RELAY) |
(a) Disconnect the A169 engine stop and start ECU connector.
(b) Disconnect the A47 ECM connector.
(c) Remove the ST relay from the No. 1 engine room relay block.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection | Condition |
Specified Condition |
|---|---|---|
|
A47-30 (STA) - ST relay terminal 2 |
Always | Below 1 Ω |
| OK | | PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE |
| NG | | REPAIR OR REPLACE HARNESS OR CONNECTOR |
