Cranking Holding Function Circuit
2GR-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: Cranking Holding Function Circuit
- Cranking Holding Function Circuit
DESCRIPTION
The cranking holding control system provides current to the starter when the ECM detects the engine switch start signal (STSW). When the ECM judges that the engine has started , the system cuts current to the starter. When the ECM receives the STSW signal, the ACC (Accessory) relay is turned off to, prevents flickering of the combination meter, clock and audio system. Also, the STAR output signal travels through the ST cut relay and the park/neutral position switch assembly to the ST relay, causing the starter to activate.
When the engine is cranking, the starter operation signal is received by the STA terminal of the ECM.
WIRING DIAGRAM
Refer to DTC P0617 P0617.
INSPECTION PROCEDURE
PROCEDURE
1. CHECK CRANKING
(a) When starting the engine, check whether the starter motor starts.
OK -- CHECK FOR INTERMITTENT PROBLEMS
NG -- Continue to next step.
2. READ VALUE USING TECHSTREAM (STARTER SIGNAL)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / Engine / Data List / Starter Signal. Read the values.
(e) Check the result when the engine switch is turned on (IG) and when the engine is started.
Standard:
OK -- INSPECT ST RELAY
NG -- Continue to next step.
3. INSPECT ECM (STSW VOLTAGE)
(a) Disconnect the A10 ECM Connector.
(b) Measure the voltage between the specified terminal of the ECM connector and body ground while cranking the engine.
Standard voltage:
(c) Reconnect the ECM connector.
NG -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM)
OK -- Continue to next step.
4. INSPECT ECM (STAR VOLTAGE)
(a) Remove the ST CUT relay from the engine room R/B.
(b) Measure the voltage between the specified terminal of the engine room R/B and body ground while cranking the engine.
Standard voltage:
(c) Reinstall the ST CUT relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - ST CUT RELAY - MAIN BODY ECU)
OK -- Continue to next step.
5. INSPECT ST CUT RELAY
(a) Remove the ST CUT relay from the engine room R/B.
(b) Measure the resistance between the terminals.
Standard resistance:
(c) Reinstall the ST CUT relay.
NG -- REPLACE ST CUT RELAY
OK -- Continue to next step.
6. INSPECT PARK/NEUTRAL POSITION SWITCH ASSEMBLY
(a) Inspect the Park/Neutral Position (PNP) switch.
(1) Disconnect the B36 switch connector.
(2) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(3) Reconnect the PNP switch connector.
NG -- REPLACE PARK/NEUTRAL POSITION SWITCH ASSEMBLY Removal
OK -- CHECK HARNESS AND CONNECTOR
7. INSPECT ST RELAY
(a) Remove the ST relay from the engine room R/B.
(b) Measure the resistance between the terminals.
Standard resistance:
(c) Reinstall the ST relay.
NG -- REPLACE ST RELAY
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (PARK/NEUTRAL POSITION SWITCH - ST RELAY)
(a) Disconnect the B36 park/neutral position switch connector.
(b) Remove the ST relay from the engine room R/B.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for open):
(d) Reinstall the ST relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT ENGINE ROOM RELAY BLOCK (ST RELAY VOLTAGE)
(a) Remove the ST relay from the engine room R/B.
(b) Measure the voltage between the specified terminal of the engine room R/B and body ground.
Standard voltage:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. INSPECT STARTER ASSEMBLY
NG -- REPAIR OR REPLACE STARTER ASSEMBLY
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STARTER RELAY - STARTER, STARTER - BATTERY)
11. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM)
(a) Disconnect the E58 main body ECU connector.
(b) Disconnect the A10 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the main body ECU connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- GO TO SMART ACCESS SYSTEM WITH PUSH-BUTTON START