DTC B1503: Exhaust Heat Management Warning Detected [11/2015 -]: Procedure

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

   Refer to INSPECTION MODE PROCEDURE [11/2015 - 12/2018] , or refer to INSPECTION MODE PROCEDURE [12/2018 -]

2. Connect the Techstream to the DLC3.
3. Turn the power switch on (IG).
4. Turn the Techstream on.
5. Enter the following menus: Body Electrical / Combination Meter / Data List.
6. 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	0 to 127.5°C (0 to 261.5°F)	75 to 100°C (167 to 212°F) (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 (167 to 212°F) 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 [11/2015 -] 

Result: 

OK 

See step  2

1. Disconnect the F6 combination meter assembly (meter circuit plate) connector.
2. Disconnect the A10 engine coolant temperature sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   F6-23 (TWS3) - A10-2 (TSW3)	Always	Below 1 Ω
   F6-3 (E2) - A10-1 (E2)	Always	Below 1 Ω
   F6-23 (TWS3) or A10-2 (TSW3) - Body ground	Always	10 kΩ or higher
   F6-3 (E2) or A10-1(E2) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Remove the engine coolant temperature sensor.

   Refer to REMOVAL [11/2015 -]

2. Inspect the engine coolant temperature sensor.

   Refer to INSPECTION [11/2015 -]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE COMBINATION METER ASSEMBLY (METER CIRCUIT PLATE). Refer to  DISASSEMBLY [11/2015 -] 

Result: 

NG 

REPLACE ENGINE COOLANT TEMPERATURE SENSOR. Refer to  REMOVAL [11/2015 -]