Open In IG1 / IG2 Power Source Circuit - Electronically Controlled Brake System

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1241/41: Low Battery Positive Voltage or Abnormally High Battery Positive Voltage

DTC C1241/41 - Low Battery Positive Voltage or Abnormally High Battery Positive Voltage

DTC C1242/42 - Open in IG1 / IG2 Power Source Circuit

DESCRIPTION

These codes are memorized when the power source voltage for the skid control ECU drops or the voltage for the ABS NO. 1, ABS NO. 2 relay operation drops.
Codes may be memorized when the voltage of the auxiliary battery temporarily drops.
When the power source voltage is too high, the skid control ECU stops functioning and outputs no DTCs, and the ABS and BRAKE warning light remain on.
HINT: DTC C1256/56 (accumulator low voltage malfunction) may be memorized if the power source voltage drops.





WIRING DIAGRAM













INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC (HYBRID CONTROL SYSTEM)
(a) Check that hybrid control system DTCs are output.

Result





B -- REPAIR HYBRID CONTROL SYSTEM
A -- Continue to next step.

2. CHECK AUXILIARY BATTERY VOLTAGE
(a) Check the auxiliary battery voltage.
Standard voltage:
10 to 14 V
NG -- CHARGE OR REPLACE AUXILIARY BATTERY
OK -- Continue to next step.

3. CHECK BRAKE CONTROL POWER SUPPLY (IG VOLTAGE)




(a) Measure the voltage of the connector.
Standard voltage:






NG -- REPLACE BRAKE CONTROL POWER SUPPLY
OK -- Continue to next step.

4. CHECK SKID CONTROL ECU




(a) Measure the voltage of the connectors.
HINT: Measure the voltage from behind the connector with the connector connected to the skid control ECU.

Standard voltage:





(b) Measure the resistance of the connectors.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.

5. CHECK SKID CONTROL ECU (BS1, R1+, SR1, BS2, R2+, SR2 VOLTAGE)




(a) Measure the voltage of the connectors.
HINT: Measure the voltage from behind the connector with the connector connected to the skid control ECU.

Standard voltage:










C -- REPAIR OR REPLACE HARNESS AND CONNECTOR
B -- REPLACE SKID CONTROL ECU
A -- Continue to next step.

6. RECONFIRM DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the power switch ON (READY).
(c) Check the same DTCs are recorded Reading and Clearing Diagnostic Trouble Codes.

Result





B -- REPLACE SKID CONTROL ECU
A -- END (DTC MAY BE STORED DUE TO TEMPORARY POWER SOURCE VOLTAGE DROP)