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A/C Pressure Switch Acura MDX I

Climate Control 22 illustrations ~1789 words

A/C Pressure Switch

The A/C pressure switch consists of a high-low pressure switch (A/C pressure switch A) and a middle pressure switch (A/C pressure switch B).

Scheme 11

Scheme 11: A/C Pressure Switch
Scheme 11: A/C Pressure Switch

Scheme 12

Scheme 12
Scheme 12
  1. High-Low pressure switch If the refrigerant pressure becomes too high (due to blockage or lack of airflow at the A/C condenser), or too low (due to leakage), the A/C pressure switch stops the A/C request a signal to the PCM and the A/C compressor stops operating.
  2. Middle pressure switch If the refrigerant pressure goes above or below 1,520 kPa (15.5 kgf/cm 2 , 220 psi), the A/C pressure switch opens or closes to signal the PCM to change the speed of the A/C condenser fan and radiator fan (high-low).

Scheme 13

Scheme 13
Scheme 13

Scheme 14

Scheme 14
Scheme 14

Scheme 15

Scheme 15: Climate Control Unit Inputs and Outputs
Scheme 15: Climate Control Unit Inputs and Outputs

Scheme 16

Scheme 16: Circuit Diagram
Scheme 16: Circuit Diagram

Scheme 17

Scheme 17
Scheme 17

Scheme 18

Scheme 18: DTC indicator A: An Open In The In-Car Temperature Sensor Circuit
Scheme 18: DTC indicator A: An Open In The In-Car Temperature Sensor Circuit

Scheme 19

Scheme 19
Scheme 19
  1. Remove the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ) and test it (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Does the in-car temperature sensor test OK? YES - Go to step 2. NO - Replace the in-car temperature sensor.
  2. Disconnect climate control unit connector B (26P).
  3. Check for continuity between the No. 17 terminal of climate control unit connector B (26P) and the No. 2 terminal of the in-car temperature sensor 2P connector. Is there continuity? YES - Go to step 4. NO- Repair open in the wire between the climate control unit and the in-car temperature sensor.
  4. Check for continuity between the No. 1 terminal of climate control unit connector B (26P) and the No. 1 terminal of the in-car temperature sensor 2P connector. Is there continuity? YES - Check for loose wires or poor connections at climate control unit connector B (26P) and at the in-car temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/ indication goes away, replace the original climate control unit. NO - Repair open in the wire between the climate control unit and the in-car temperature sensor.

Scheme 20

Scheme 20: DTC Indicator B: A Short In The In-Car Temperature Sensor Circuit
Scheme 20: DTC Indicator B: A Short In The In-Car Temperature Sensor Circuit
  1. Remove the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ).
  2. Test the in-car temperature sensor (see «IN-CAR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__in-car-temperature-sensor-test) ). Does the in-car temperature sensor test OK? YES - Go to step 3. NO - Replace the in-car temperature sensor.
  3. Disconnect climate control unit connector B (26P).
  4. Check for continuity between the No. 17 terminal of climate control unit connector B (26P) and body ground. Is there continuity? YES - Repair short to body ground in the wire between the climate control unit and the in-car temperature sensor. NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

Scheme 21

Scheme 21: DTC Indicator C: An Open In The Outside Air Temperature Sensor Circuit
Scheme 21: DTC Indicator C: An Open In The Outside Air Temperature Sensor Circuit

Scheme 22

Scheme 22
Scheme 22
  1. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__outside-air-temperature-sensor-test) ) and test it (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__outside-air-temperature-sensor-test) ). Does the outside air temperature sensor test OK? YES - Go to step 2. NO - Replace the outside air temperature sensor.
  2. Disconnect climate control unit connector B (26P).
  3. Check for continuity between the No. 18 terminal of climate control unit connector B (26P) and the No. 1 terminal of the outside air temperature sensor 2P connector. Is there continuity? YES - Go to step 4. NO - Repair open in the wire between the climate control unit and the outside air temperature sensor.
  4. Check for continuity between the No. 1 terminal of climate control unit connector B (26P) and the No. 2 terminal of the outside air temperature sensor 2P connector. Is there continuity? YES - Check for loose wires or poor connections at climate control unit connector B (26P) and at the outside air temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/ indication goes away, replace the original climate control unit. NO - Repair open in the wire between the climate control unit and the outside air temperature sensor.

Scheme 23

Scheme 23: DTC Indicator D: A Short In The Outside Air Temperature Sensor Circuit
Scheme 23: DTC Indicator D: A Short In The Outside Air Temperature Sensor Circuit
  1. Remove the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__outside-air-temperature-sensor-test) ).
  2. Test the outside air temperature sensor (see «OUTSIDE AIR TEMPERATURE SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__outside-air-temperature-sensor-test) ). Does the outside air temperature sensor test OK? YES - Go to step 3. NO - Replace the outside air temperature sensor.
  3. Disconnect climate control unit connector B (26P).
  4. Check for continuity between the No. 18 terminal of climate control unit connector B (26P) and body ground. Is there continuity? YES - Repair short to body ground in the wire between the climate control unit and the outside air temperature sensor. NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.

Scheme 24

Scheme 24: DTC Indicator E: An Open In The Sunlight Sensor Circuit
Scheme 24: DTC Indicator E: An Open In The Sunlight Sensor Circuit

Scheme 25

Scheme 25
Scheme 25
  1. Disconnect the sunlight sensor 2P connector.
  2. Disconnect climate control unit connector B (26P).
  3. Check for continuity between the No. 19 terminal of climate control unit connector B (26P) and the No. 1 terminal of the sunlight sensor 2P connector. Is there continuity? YES - Go to step 4. NO - Repair open in the wire between the climate control unit and the sunlight sensor.
  4. Check for continuity between the No. 1 terminal of climate control unit connector B (26P) and the No. 2 terminal of the sunlight sensor 2P connector. Is there continuity? YES - Go to step 5. NO - Repair open in the wire between the climate control unit and the sunlight sensor.
  5. Reconnect the sunlight sensor 2P connector.
  6. Reconnect climate control unit connector B (26P).
  7. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Does the sunlight sensor test OK? YES - Check for loose wires or poor connections at climate control unit connector B (26P) and at the sunlight sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. NO - Replace the sunlight sensor.

Scheme 26

Scheme 26: DTC Indicator F: A Short In The Sunlight Sensor Circuit
Scheme 26: DTC Indicator F: A Short In The Sunlight Sensor Circuit
  1. Disconnect the sunlight sensor 2P connector.
  2. Disconnect climate control unit connector B (26P).
  3. Check for continuity between the No. 19 terminal of climate control unit connector B (26P) and body ground. Is there continuity? YES - Repair short to body ground in the wire between the climate control unit and the sunlight sensor. NO - Go to step 4.
  4. Reconnect the sunlight sensor 2P connector.
  5. Reconnect climate control unit connector B (26P).
  6. Test the sunlight sensor (see «SUNLIGHT SENSOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__sunlight-sensor-test) ). Does the sunlight sensor test OK? YES - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. NO - Replace the sunlight sensor.

Scheme 27

Scheme 27: DTC Indicator G: An Open In The Evaporator Temperature Sensor Circuit
Scheme 27: DTC Indicator G: An Open In The Evaporator Temperature Sensor Circuit

Scheme 28

Scheme 28
Scheme 28
  1. Disconnect climate control unit connector B (26P).
  2. Disconnect the evaporator temperature sensor 2P connector.
  3. Check for continuity between the No. 20 terminal of climate control unit connector B (26P) and the No. 2 terminal of the evaporator temperature sensor 2P connector. Is there continuity? YES - Go to step 4. NO - Repair open in the wire between the climate control unit and the evaporator temperature sensor.
  4. Check for continuity between the No. 1 terminal of climate control unit connector B (26P) and the No. 1 terminal of the evaporator temperature sensor 2P connector. Is there continuity? YES - Go to step 5. NO - Repair open in the wire between the climate control unit and the evaporator temperature sensor.
  5. Reconnect climate control unit connector B (26P).
  6. Connect a new evaporator temperature sensor to the evaporator temperature sensor 2P connector, then run the self-diagnostic (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control) ). Is DTC G indicated? YES - Check for loose wires or poor connections at climate control unit connector B (26P) and at the evaporator temperature sensor 2P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. NO - Replace the original evaporator temperature sensor.

Scheme 29

Scheme 29: DTC Indicator H: A Short In The Evaporator Temperature Sensor Circuit
Scheme 29: DTC Indicator H: A Short In The Evaporator Temperature Sensor Circuit
  1. Disconnect the evaporator temperature sensor 2P connector.
  2. Disconnect climate control unit connector B (26P).
  3. Check for continuity between the No. 20 terminal of climate control unit connector B (26P) and body ground. Is there continuity? YES - Repair short to body ground in the wire between the climate control unit and the evaporator temperature sensor. NO - Go to step 4.
  4. Reconnect climate control unit connector B (26P).
  5. Connect a new evaporator temperature sensor to the evaporator temperature sensor 2P connector, then run the self-diagnostic (see «GENERAL TROUBLESHOOTING INFORMATION»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control) ). Is DTC H indicated? YES - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. NO - Replace the original evaporator temperature sensor.

Scheme 30

Scheme 30: DTC Indicator I: An Open In The Air Mix Control Motor Circuit
Scheme 30: DTC Indicator I: An Open In The Air Mix Control Motor Circuit
  1. Test the air mix control motor (see «AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control) ). Does the air mix control motor test OK? YES - Go to step 2. NO - Replace the air mix control motor.
  2. Disconnect the air mix control motor 7P connector.
  3. Disconnect climate control unit connector B (26P).
  4. Check for continuity between the following terminals of climate control unit connector B (26P) and the air mix control motor 7P connector. AIR MIX CONTROL MOTOR 7P CONNECTOR TERMINALS REFERENCE 26P: 7P: No. 1 No. 5 No. 3 No. 7 No. 21 No. 3 No. 25 No. 2 No. 26 No. 1 Is there continuity? YES - Check for loose wires or poor connections at climate control unit connector B (26P) and at the air mix control motor 7P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit. NO - Repair any open in the wire(s) between the climate control unit and the air mix control motor.

Scheme 31

Scheme 31: DTC indicator J: A Short In The Air Mix Control Motor Circuit
Scheme 31: DTC indicator J: A Short In The Air Mix Control Motor Circuit

Scheme 32

Scheme 32
Scheme 32
  1. Test the air mix control motor (see «AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control) ). Does the air mix control motor test OK? YES - Go to step 2. NO - Replace the air mix control motor.
  2. Disconnect the air mix control motor 7P connector.
  3. Disconnect climate control unit connector B (26P).
  4. Check for continuity between body ground and climate control unit connector B (26P) terminals No. 1, 3, 21, 25, and 26 individually. Is there continuity? YES - Repair any short to body ground in the wire(s) between the climate control unit and the air mix control motor. NO - Go to step 5.
  5. Turn the ignition switch ON (II), and check the same terminals for voltage. Is there any voltage? YES - Repair any short to power in the wire(s) between the climate control unit and the air mix control motor. This short may also damage the climate control unit. Repair the short to power before replacing the climate control unit. NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit.