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Home >> Toyota >> 2021 >> Highlander Platinum, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 10 (Meter / Gauge System (12.3 Inch Display) - Diagnostic Codes & Circuit Tests) >> METER / GAUGE SYSTEM (for 12.3 Inch Display) >> DTC B1503-09: Exhaust Heat Management Component Failure [10/2022 - ] >> Description

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

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This DTC is stored and an engine coolant temperature warning is displayed when the combination meter assembly detects a malfunction in the temperature switch that is connected to the combination meter assembly via direct line.

HINT: 

When this DTC is stored, the engine coolant temperature receiver gauge in the combination meter assembly indicates an engine coolant temperature of 125°C (257°F).

DTC No. Detection Item DTC Detection Condition Trouble Area
B1503-09 Exhaust Heat Management Component Failure Diagnosis Condition:
  • Ignition switch ON
  • IG power source voltage is 9.5 V or more

Malfunction Status:

  1. Open in engine coolant temperature switch circuit

Malfunction Time:

  1. 3 seconds or more
  • Temperature switch
  • Harness or connector
  • Combination meter assembly