P15B3
DTC P0536-P0538 or P15B3
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0536
- Air Conditioning (A/C) Evaporator Temperature Sensor 2 Performance
DTC P0537
- Air Conditioning (A/C) Evaporator Temperature Sensor 2 Circuit Low Voltage
DTC P0538
- Air Conditioning (A/C) Evaporator Temperature Sensor 2 Circuit High Voltage
DTC P153B
- Air Conditioning (A/C) Evaporator Temperature Sensor 2 not Plausible
Circuit Description
The Evaporator Temperature Sensor 2 measures the temperature on the low pressure side of the AC Compressor.
The Hybrid Powertrain control module (HPCM2) supplies the evaporator temperature sensor with a low reference circuit and 5-volt signal circuit. The HPCM2 determines the voltage drop across the sensor, which is proportional to temperature. As the temperature increases, the sensor resistance decreases and the voltage signal decreases. As the temperature decreases, the sensor resistance increases and the voltage signal increases.
Conditions for Running the DTC
DTC P153B makes comparisons between other temperature sensors to determine if the A/C Evaporator Temperature Sensor 2 reading is close to other temperature readings after a soak period. P153B is intended to run after a long ambient soak period, such as being parked overnight, when a hot engine condition has cooled, etc.
DTCs P0537 and P0538 monitor A/C Evaporator Temperature Sensor 2 for out of range conditions.
DTC P0536 looks for the A/C Evaporator Temperature Sensor 2 to go down in temperature when the compressor is operated with a cold engine and after the compressor has been off for one hour.
P1536
* System voltage above 9V
* Hybrid Powertrain Control Module 2 is awake and communicating.
* None of these DTCs may be active: P0537;P0538, P0073; P0072; P0071, P0119; P0118; P0117; P0116, P0606.
* Engine coolant temperature must be within 15C degrees of outside air temperature.
* AC compressor must have been off for an hour since the last time the AC compressor was on.
* AC compressor must be turned on for one minute.
P1537 or P0538
* System voltage above 9V
* Hybrid Powertrain Control Module 2 is awake and communicating.
P153B
* HPCM2 is awake and communicating.
* None of these DTCs may be active: P0537;P0538, P0073; P0072; P0071, P0119; P0118; P0117; P0116, P0531, P0532; P0533, P0606
* Outside Air Temperature raw and corrected values must have had a chance to settle out. Once this occurs these variables are assigned a status of valid. May need to have some time driving in EV mode
* Engine coolant temperature must be within 15C degrees of outside air temperature (i.e., cool engine
* Outside Air Temperature must be between 0C and +55C.
* AC compressor must have been off for an hour since the last time the AC compressor was on.
Conditions for Setting the DTC
P0536
The difference between the A/C Evaporator Temperature Sensor 2 before compressor on and after compressor on changes less than 2 degrees C over a 30 second period.
P0537
The HPCM2 detects the evaporator temperature sensor signal circuit is less than -40°C (-40°F) for more than 15 seconds.
P0538
The HPCM2 detects the evaporator air temperature sensor signal circuit is more than 95C (203F) for more than 4 seconds.
P153B
* The difference between the A/C Evaporator Temperature Sensor 2 and the Outside Air Temperature value is greater than 10 degrees C and
* the difference between the A/C Evaporator Temperature Sensor 2 and the temperature calculated from the current High Side Refrigerant Pressure Sensor reading is greater than 10 degrees C.
Action Taken When the DTC Sets
These are type B DTCs.
Conditions for Clearing the DTC
These are type B DTCs.
Reference Information
Schematic Reference
HVAC Schematics HVAC - Automatic
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1 A4
Description and Operation
* Automatic HVAC Description and Operation HVAC - Automatic
* Heating and Air Conditioning System Description and Operation Heating and Air Conditioning System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool A/C Evaporator Temperature Sensor parameter. The reading should be between -40 to +85°C (-40 to +185°F) and change with evaporator temperature changes.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at theB39B evaporator temperature sensor 2.
2. Test for less than 10 ohms between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K114B HPCM2.
3. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal A and low reference circuit terminal B.
• If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the K114B HPCM2.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K114B HPCM2.
4. If all circuits test normal, test or replace the evaporator temperature sensor.
Component Testing
1. Test the evaporator temperature sensor by varying the sensor temperature while monitoring the sensor resistance.
2. Compare the readings with the Sensor Resistance Table Electrical Specifications and verify that the resistance is within 5 percent of the specification.
• If not within the specified range, replace the sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* HVAC Component Replacement Reference HVAC Component Replacement Reference
* Control Module References Control Module References for HPCM2 control module replacement, setup, and programming