DTC    C15C7/78    DC Motor Power Source Voltage Malfunction

DTC    C15C8/79    Power Supply Relay Failure

for Preparation Click here


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.
  1. VGRS fuse
  2. Wire harness and connector
  3. Power source circuit
  4. Steering control ECU
C15C8/79
The steering control ECU detects a malfunction in the power source relay or an open circuit.
  1. VGRS fuse
  2. Wire harness and connector
  3. Steering control ECU

WIRING DIAGRAM


C111969E01


INSPECTION PROCEDURE

CAUTION:
The fault may be intermittent. Check harnesses and connectors thoroughly and retest.

1.CHECK STEERING CONTROL ECU


    C107435E03

  1. Record and clear the DTCs (Click here).

  1. Start the engine.

  1. 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



B
CHECK OR REPAIR HARNESS AND FUSE

C
CHECK OR REPAIR CHARGING SYSTEM
A


2.CHECK DTC

  1. Turn the engine switch off.

  1. Connect the intelligent tester to the DLC3.

  1. Turn the engine switch on (IG) and turn the intelligent tester on.

  1. Check for DTCs (Click here).

    OK:
    Neither DTC C15C7/78 nor C15C8/79 is output.



NG
REPLACE STEERING CONTROL ECU
OK

END