DTC B1503-09: Exhaust Heat Management Component Failure [10/2022 - ]: Procedure

1. Put the engine in inspection mode (maintenance mode).

   HINT: 

   Refer to INSPECTION MODE PROCEDURE [10/2022 - ]

2. Read the Data List according to the display on the Techstream.

   Body Electrical > Combination Meter > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Coolant Temperature	Engine coolant temperature	Min.: 0.0°C, Max.: 127.1°C or Unset	75 to 100°C: After warming up engine	-

   Body Electrical > Combination Meter > Data List 

   Tester Display
   Coolant Temperature

   OK

   Engine coolant temperature displayed on the Techstream is 75 to 100°C after the engine is warmed.

   NOTE:

   If the engine coolant temperature exceeds 100°C, the cooling system is malfunctioning. Stop the engine immediately.

   HINT: 

   The coolant temperature value in this inspection is the data sent from the engine coolant temperature sensor for the SFI system.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

GO TO EXHAUST HEAT RECIRCULATION SYSTEM. Refer to  PROBLEM SYMPTOMS TABLE [10/2022 - ] 

Result: 

OK 

See step  2

• SST: 09843-18040 

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Pre-procedure1

• Turn the ignition switch off.
• Disconnect the J2 temperature switch connector.

• Connect SST to terminal J2-2 (TWS2) and body ground.

  Result

  Proceed to
  NEXT

Post-procedure1

• None

Result: 

NEXT 

See step  3

1. Clear the DTCs.

   Body Electrical > Combination Meter > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  4

1. Check for DTCs.

   Body Electrical > Combination Meter > Trouble Codes 

   Result

   Result	Proceed to
   B1503-09 is not output	A
   B1503-09 is output	B

Result: 

A 

REPLACE TEMPERATURE SWITCH. Refer to  REMOVAL [10/2022 - 08/2023]  , or refer to  REMOVAL [08/2023 - ] 

Result: 

B 

See step  5

Pre-procedure1

• Disconnect the SST.
• Disconnect the C19 combination meter assembly connector.

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

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  J2-2 (TWS2) - C19-27 (TWS3)	Always	Below 1 Ω	Ω
  J2-1 (GND) - Body ground	Always	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE COMBINATION METER ASSEMBLY. Refer to  REMOVAL [10/2022 - 10/2024]  , or refer to  REMOVAL [10/2024 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR