Lexus IS250 · Service Manual ENGINE

B2274

Diagnostic trouble codes

DESCRIPTION

This DTC is output when there is a problem in the ACC output circuit, which is from the inside of the power source control ECU to the ACC or PWR POINT relay.

HINT:
When the power source control ECU is replaced with a new one and the negative (-) battery terminal is connected, the power source mode becomes the IG-ON mode. When the battery is removed and reinstalled, the power source mode that was selected when the battery was removed is restored.

DTC No.
 DTC Detection Condition
 Trouble Area
B2274
 ACC relay actuation circuit inside power source control ECU or other related circuit is malfunctioning
  1. AM2 fuse
  2. Cowl side J/B RH
  3. Power source control ECU
  4. Wire harness or connector

WIRING DIAGRAM

B112579E02

INSPECTION PROCEDURE


1. INSPECT FUSE (AM2)

  1. Remove the AM2 fuse from the cowl side J/B RH.

  1. Measure the resistance of the fuse.

    Standard resistance:
    Below 1 Ω



 NG
REPLACE FUSE
OK


2. CHECK CONNECTORS

  1. Check that the connectors are securely connected and the terminals are not deformed or loose.

    OK:
    The connectors are securely connected and the terminals are not deformed or loose.



 NG
REPAIR OR REPLACE CONNECTORS
OK


3. CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - BATTERY AND BODY GROUND)

  1. B128304E19
    Disconnect the J55 ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-33 (AM1) - Body ground
    		 Always
    		 10 to 14 V
    J55-12 (AM2) - Body ground
    		 Always
    		 10 to 14 V

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-6 (GND2) - Body ground
    		 Always
    		 Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4. CHECK COWL SIDE JUNCTION BLOCK RH (ACC RELAY, PWR OUTLET RELAY)

  1. A118478E02
    Disconnect the RD and RA J/B connectors.

  1. Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    RD-2 - RA-5 or RD-7
    		 Always
    		 68 to 250 Ω at 20°C (68°F)



NG
Go to step 8
OK


5. CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - BATTERY AND BODY GROUND)

  1. A118479E02
    Measure the resistance according to the value(s) in the table below.

    Standard resistance:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-11 (ACCD) - RD-2
    		 Always
    		 Below 1 Ω
    J55-11 (ACCD) - Body ground
    		 Always
    		 10 kΩ or higher
    RA-5 - Body ground
    		 Always
    		 Below 1 Ω
    RD-7 - Body ground
    		 Always
    		 Below 1 Ω

  1. Connect each J/B connector with the power source control ECU connector disconnected.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-11 (ACCD) - Body ground
    		 Engine switch on (IG)
    		 Below 1 V



NG
Go to step 9
OK


6. INSPECT POWER SOURCE CONTROL ECU

  1. B112480E06
    Reconnect the J55 ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-11 (ACCD) - Body ground
    		 Engine switch off
    		 Below 1 V
    Engine switch on (IG)
    		 8 to 14 V



NG
REPLACE POWER SOURCE CONTROL ECU
OK


7. RECHECK FOR DTC

  1. Delete the DTCs (Click here).

  1. Check for DTCs again.

    OK:
    DTC B2274 is not output.



 NG
REPLACE POWER SOURCE CONTROL ECU
OK

CHECK INTERMITTENT PROBLEMS

8. REPLACE FAULTY J/B AND CHECK POWER SOURCE CONTROL ECU

  1. B112480E06
    Replace a faulty J/B and then connector the power source control ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-11 (ACCD) - Body ground
    		 Engine switch off
    		 Below 1 V
    Engine switch on (IG)
    		 8 to 14 V



NG
REPLACE POWER SOURCE CONTROL ECU
OK

END

9. REPAIR OR REPLACE WIRE HARNESS OR CONNECTOR AND CHECK POWER SOURCE CONTROL ECU

  1. B112480E06
    Repair or replace a faulty wire harness or connector and then connect the power source control ECU connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard voltage:
    Tester Connection (Symbols)
    		 Condition
    		 Specified Condition
    J55-11 (ACCD) - Body ground
    		 Engine switch off
    		 Below 1 V
    Engine switch on (IG)
    		 8 to 14 V



NG
REPLACE POWER SOURCE CONTROL ECU
OK

END


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