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Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating / Air Conditioning System (Except HV, W/ Auto A/C) - Diagnostic Codes (2 Of 2) >> AIR CONDITIONING SYSTEM (for Gasoline Model with Automatic Air Conditioning System) >> DTC P153B-15: Rear Evaporator Temperature Sensor Circuit Short to Battery or Open [11/2023 - ] >> Description

DTC P153B-15: Rear Evaporator Temperature Sensor Circuit Short to Battery or Open [11/2023 - ]: Description

The rear evaporator temp. sensor (No. 2 air conditioning harness assembly) is installed to the evaporator in the rear cooling unit to detect the temperature of the cooled air that has passed through the evaporator, which is used to control the air conditioning system. It sends signals to the air conditioning amplifier assembly. The resistance of the rear evaporator temp. sensor (No. 2 air conditioning harness assembly) changes in accordance with the temperature of the cooled air that has passed through the evaporator. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.

The air conditioning amplifier assembly applies voltage to the rear evaporator temp. sensor (No. 2 air conditioning harness assembly) and reads voltage changes as the resistance of the rear evaporator temp. sensor (No. 2 air conditioning harness assembly) changes. This sensor is used for frost prevention.

DTC No. Detection Item DTC Detection Condition Trouble Area Memory DTC Output from Priority
P153B-15 Rear Evaporator Temperature Sensor Circuit Short to Battery or Open Diagnosis Condition:
  1. Ignition switch ON

Malfunction:

  1. Open or short (+B) in rear evaporator temperature sensor circuit

Detection Time:

  1. Continuously for 4 seconds or more
  • Rear evaporator temp. sensor (No. 2 air conditioning harness assembly)
  • Harness or connector
  • Air conditioning amplifier assembly
Memorized Air Conditioner A
DTC DETECTION CONDITION COMBINATION TABLE

  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition Ignition switch ON
Malfunction Open in rear evaporator temperature sensor circuit -
Short (+B) in rear evaporator temperature sensor circuit -
Detection Time Continuously for 4 seconds or more Continuously for 4 seconds or more
Trip Count 1 trip 1 trip

HINT: 

If the conditions of either of these patterns are detected, a DTC will be stored.