Dtc C15C7/78 Dc Motor Power Source Voltage Malfunction
Steering. Lexus Gs430, Gs300. Uzs190 Grs190
DESCRIPTION
WIRING DIAGRAM
INSPECTION PROCEDURE
CHECK STEERING CONTROL ECU
CHECK DTC
DTC C15C7/78 DC Motor Power Source Voltage Malfunction |
DTC C15C8/79 Power Supply Relay Failure |
DESCRIPTION
The steering control ECU monitors PIG (motor power source voltage) and detects a malfunction in the power supply relay (located inside the steering control ECU).If the steering control ECU detects a malfunction, it will turn on the master warning light, store these DTCs, and stop VGRS operation.DTC No.
| DTC Detecting Condition
| Trouble Area
|
C15C7/78
| The steering control ECU detects that the IG terminal voltage is between 9 and 16 V, and the PIG terminal voltage is less than 7 V or more than 18.5 V for 2.4 seconds.
| - VGRS fuse
- Wire harness and connector
- Power source circuit
- Steering control ECU
|
C15C8/79
| The steering control ECU detects a malfunction in the power source relay or an open circuit.
| - VGRS fuse
- Wire harness and connector
- Steering control ECU
|
WIRING DIAGRAM
INSPECTION PROCEDURE
- CAUTION:
- The fault may be intermittent. Check harnesses and connectors thoroughly and retest.
1.CHECK STEERING CONTROL ECU |
Record and clear the DTCs (Click here).
Start the engine.
Measure the voltage according to the value(s) in the table below.
- Voltage:
Tester connection
| Specified condition
| Proceed to
|
A42-8 (PIG) - A42-7 (PGND)
| 9 to 16 V
| A
|
A42-8 (PIG) - A42-7 (PGND)
| Below 9 V
| B
|
A42-8 (PIG) - A42-7 (PGND)
| Above 16 V
| C
|
| CHECK OR REPAIR HARNESS AND FUSE |
|
|
| CHECK OR REPAIR CHARGING SYSTEM |
|
|
Turn the engine switch off.
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the intelligent tester on.
Check for DTCs (Click here).
- OK:
- Neither DTC C15C7/78 nor C15C8/79 is output.
| REPLACE STEERING CONTROL ECU |
|
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