| Last Modified: 11-27-2007 | 1.6 J | |
| Service Category: Engine/Hybrid System | Section: Engine Control | |
| Model Year: 2008 | Model: LX570 | Doc ID: RM000000WZ303NX |
| Title: 3UR-FE ENGINE CONTROL: SFI SYSTEM: DESCRIPTION (2008 LX570) | ||
|
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 performs a firing judgment, the system cuts current to the starter. When an ECM receives the STSW signal, it turns on the ACC cut, which prevents flickering of the combination meter, clock, audio system, etc. Also, the ECM sends a signal to the ECM STAR terminal. Then the STAR output signal travels through the Park/Neutral Position (PNP) switch to the starter relay, causing the starter to activate.
When the engine is cranking, the starter operation signal is sent to the ECM STA terminal.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
|
1. |
CHECK CRANKING |
(a) Check the cranking of the engine.
Result
|
Result |
Proceed to |
|---|---|
|
Cranking possible and holding control operates |
A |
|
Does not crank |
B |
|
Cranking possible but holding control does not operate |
C |
|
|
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 and ECT / Data List / Starter Signal.
(e) Check the value displayed on the Techstream when the engine switch is turned to the START.
Standard:
|
Engine Switch Position |
Display (Starter Signal) |
|---|---|
|
On (IG) |
OFF |
|
START |
ON |
|
|
3. |
INSPECT STARTER RELAY (ST) |
|
(a) Remove the starter relay (ST) from the engine room relay block. |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
3 - 5 |
No battery voltage applied to terminals 1 and 2 |
10 kΩ or higher |
|
3 - 5 |
Battery voltage applied to terminals 1 and 2 |
Below 1 Ω |
|
|
4. |
CHECK HARNESS AND CONNECTOR (ST RELAY - PNP SWITCH) |
(a) Remove the starter relay (ST) from the engine room relay block.
(b) Disconnect the C19 PNP switch.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
ST relay (1) - C19-5 |
Always |
Below 1 Ω |
|
ST relay (1) or C19-5 - Body ground |
Always |
10 kΩ or higher |
|
|
5. |
CHECK STARTER RELAY (POWER SOURCE) |
(a) Remove the ST relay from the engine room relay block.
(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
ST relay (2) - ST relay (5) |
Always |
11 to 14 V |
|
|
6. |
INSPECT STARTER |
(a) Inspect the starter
.
|
|
7. |
INSPECT STARTER CUT RELAY (ST CUT) |
|
|
(a) Remove the starter cut relay (ST CUT) from the engine room relay block. |
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
3 - 5 |
No battery voltage applied to terminals 1 and 2 |
10 kΩ or higher |
|
3 - 5 |
Battery voltage applied to terminals 1 and 2 |
Below 1 Ω |
|
|
8. |
CHECK HARNESS AND CONNECTOR (ST CUT RELAY - PNP SWITCH, ECM) |
(a) Remove the starter cut relay (ST CUT) from the engine room relay block.
(b) Disconnect the C19 PNP switch connector.
(c) Disconnect the C53 ECM connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
ST CUT relay (5) - C53-16 (STAR) |
Always |
Below 1 Ω |
|
ST CUT relay (3) - C19-4 |
Always |
Below 1 Ω |
|
ST CUT relay (5) or C53-16 (STAR) - Body ground |
Always |
10 kΩ or higher |
|
ST CUT relay (3) or C19-4 - Body ground |
Always |
10 kΩ or higher |
|
|
9. |
INSPECT PARK/NEUTRAL POSITION SWITCH |
|
(a) Inspect the Park/Neutral Position (PNP) switch. (1) Disconnect the C19 PNP switch connector. (2) Measure the resistance according to the value(s) in the table below. Standard Resistance:
|
|
|
10. |
CHECK HARNESS AND CONNECTOR (PNP SWITCH - ECM) |
(a) Disconnect the C19 PNP switch connector.
(b) Disconnect the A38 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
C19-5 - A38-46 (STA) |
Always |
Below 1 Ω |
|
C19-5 or A38-46 (STA) - Body ground |
Always |
10 kΩ or higher |
Result
|
Result |
Proceed to |
|---|---|
|
NG |
A |
|
OK |
B |
|
|
11. |
CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ECM) |
(a) Disconnect the E4 main body ECU connector.
(b) Disconnect the A38 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
E4-4 (STSW) - A38-14 (STSW) |
Always |
Below 1 Ω |
|
E4-4 (STSW) or A38-14 (STSW) - Body ground |
Always |
10 kΩ or higher |
|
|
12. |
CHECK HARNESS AND CONNECTOR (ST CUT RELAY - PNP SWITCH, ECM) |
(a) Remove the starter cut relay (ST CUT) from the engine room relay block.
(b) Disconnect the C19 PNP switch connector.
(c) Disconnect the C53 ECM connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
ST CUT relay (5) - C53-16 (STAR) |
Always |
Below 1 Ω |
|
ST CUT relay (3) - C19-4 |
Always |
Below 1 Ω |
|
ST CUT relay (5) or C53-16 (STAR) - Body ground |
Always |
10 kΩ or higher |
|
ST CUT relay (3) or C19-4 - Body ground |
Always |
10 kΩ or higher |
|
|
26. |
REPLACE ECM |
(a) Replace the ECM
.
|
|
27. |
CONFIRM WHETHER MALFUNCTION HAS BEEN SUCCESSFULLY REPAIRED |
(a) Check the starter operation.
OK:
Malfunction has been repaired successfully.
|
|
|