Rear Air Conditioning Acura MDX I

Scheme 1

How to Retrieve a DTC

The rear heater-A/C control panel-unit has a self-diagnostic function. To run the self-diagnostic function, do the following

Scheme 2

1. Turn the fan switch OFF.
2. Turn the ignition switch ON (II).
3. Turn the rear A/C manual switch ON.
4. Press the vent switch and then the heat switch. Continue to hold both switches down until the vent indicator comes on for two seconds, then it will blink the diagnostic trouble code (DTC) to indicate a faulty component. If no DTCs are found, the indicator will not blink after the initial two seconds light. NOTE: If no DTCs are found, but the system still does not function properly, go to the Symptom Troubleshooting Index. Canceling the Self-diagnostic Function
5. Turn the ignition switch OFF to cancel the self-diagnostic function. After completing repair work, run the self-diagnostic function again to make sure that there are no other malfunctions.

DTC Troubleshooting Index

DTC TROUBLESHOOTING INDEX

In case of multiple problems, the vent indicator will indicate only the DTC with the least number of blinks.

Symptom Troubleshooting Index

SYMPTOM TROUBLESHOOTING INDEX

Scheme 3

Scheme 4

Scheme 5

DTC CODES

DTC CHART

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

1. Check the No. 52 (30 A) fuse in the under-hood fuse/relay box, and the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box. Are the fuses OK? YES - Go to step 2. NO - Replace the fuse(s), and recheck.
2. Connect the No. 2 terminal of the rear blower motor 2P connector to body ground with a jumper wire.
3. Turn the ignition switch ON (II). Does the rear blower motor run? YES - Go to step 4. NO - Go to step 17 .
4. Turn the ignition switch OFF.
5. Disconnect the jumper wire.
6. Disconnect the rear power transistor 4P connector.
7. Check for continuity between the No. 3 terminal of the rear power transistor 4P connector and body ground. Is there continuity? YES - Go to step 8. NO - Check for an open in the wire between the rear power transistor and body ground. If the wire is OK, check for poor ground at G501.
8. Connect the No. 2 and No. 3 terminals of the rear power transistor 4P connector with a jumper wire.
9. Turn the ignition switch ON (II). Does the rear blower motor run at high speed? YES - Go to step 10. NO - Repair open in the wire between the rear power transistor and the rear blower motor.
10. Turn the ignition switch OFF.
11. Disconnect the jumper wire.
12. Disconnect the rear heater-A/C control panel-unit 14P connector.
13. Check for continuity between the No. 10 and No. 11 terminals of the rear heater-A/C control panel-unit 14P connector and body ground individually. Is there continuity? YES - Repair any short to body ground in the wire (s) between the rear heater-A/C control panel-unit and the rear power transistor. NO - Go to step 14.
14. Check for continuity between the following terminals of the rear heater-A/C control panel-unit 14P connector and the rear power transistor 4P connector. REAR HEATER-A/C CONTROL PANEL-UNIT 14P CONNECTOR AND THE REAR POWER TRANSISTOR 4P CONNECTOR 14P 4P No. 10 No. 1 No. 11 No. 4 Is there continuity? YES - Go to step 15. NO - Repair any open in the wire (s) between the rear heater-A/C control panel-unit and the rear power transistor.
15. Reconnect the rear heater-A/C control panel-unit 14P connector.
16. Test the rear power transistor (see «REAR POWER TRANSISTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). Is the rear power transistor OK? YES - Check for loose wires or poor connections at the rear heater-A/C control panel-unit 14P connector and at the rear power transistor 4P connector. If the connections are good, substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit. NO - Replace the rear power transistor.
17. Disconnect the jumper wire.
18. Disconnect the rear blower motor 2P connector.
19. Measure the voltage between the No. 1 terminal of the rear blower motor 2P connector and body ground. Is there battery voltage? YES - Replace the rear blower motor (see «REAR BLOWER MOTOR REPLACEMENT»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). NO - Go to step 20.
20. Turn the ignition switch OFF.
21. Remove the rear blower motor relay from the left side of rear heater-A/C panel-unit, and test it (see «POWER RELAY TEST»(/acura/mdx/i-2000-2006/remont/body-electrical/#relays__power-relay-test) ). Does the relay test OK? YES - Go to step 22. NO - Replace the rear blower motor relay.
22. Measure the voltage between the No. 1 terminal of the rear blower motor relay 4P connector and body ground. Is there battery voltage? YES - Go to step 23. NO - Repair open in the wire between the No. 52 fuse in the under-hood fuse/relay box and the rear blower motor relay.
23. Turn the ignition switch ON (II).
24. Measure the voltage between the No. 2 terminal of the rear blower motor relay 4P connector and body ground. Is there battery voltage? YES - Go to step 25. NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the rear blower motor relay.
25. Turn the ignition switch OFF.
26. Check for continuity between the No. 4 terminal of the rear blower motor relay 4P connector and body ground. Is there continuity? YES - Repair open in the BLU/YEL wire between the rear blower motor relay and the rear blower motor. NO - Check for an open in the wire between the rear blower motor relay and body ground. If the wire is OK, check for poor ground at G501.

DTC 2: A Problem in the Rear Air Mix Control Linkage, Door, or Motor

1. Test the rear air mix control motor (see «REAR AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). Does the rear air mix control motor test OK? YES - Substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit. NO - Go to step 2.
2. Remove the rear air mix control motor (see «REAR AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ).
3. Check the rear air mix control linkage and door for smooth movement. Do the rear air mix control linkage and door move smoothly? YES - Replace the rear air mix control motor. NO - Repair the rear air mix control linkage and door.

Scheme 15

1. Disconnect the rear air mix control motor 7P connector.
2. Disconnect the rear heater-A/C control panel-unit 14P connector.
3. Check for continuity between following terminals of the rear heater-A/C control panel-unit 14P connector and the rear air mix control motor 7P connector. REAR HEATER-A/C CONTROL PANEL-UNIT 14P AND REAR AIR MIX CONTROL MOTOR 7P 14P 7P No. 3 No. 1 No. 5 No. 5 No. 7 No. 3 No. 9 No. 2 No. 12 No. 7 Is there continuity? YES - Check for loose wires or poor connections at the rear heater-A/C control panel-unit 14P connector and at the rear air mix control motor 7P connector. If the connections are good, substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit. NO - Repair any open in the wire(s) between the rear heater-A/C control panel-unit and the rear air mix control motor.

Scheme 16

Scheme 17

1. Disconnect the rear air mix control motor 7P connector.
2. Disconnect the rear heater-A/C control panel-unit 14P connector.
3. Check for continuity between body ground and the rear heater-A/C control panel-unit 14P connector terminals No. 3, 5, 7, 9, and 12 individually. Is there continuity? YES - Repair any short to body ground in the wire(s) between the rear heater-A/C control panel-unit and the rear air mix control motor. NO - Go to step 4.
4. Turn the ignition switch ON (II), and check the same terminals for voltage. Is there any voltage? YES - Repair short to power in the wire between the rear heater-A/C control panel-unit and the rear air mix control motor. This short may also damages the rear heater-A/C control panel-unit. Repair the short to power before replacing the rear heater-A/C control panel-unit. NO - Substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit.

Scheme 18

Scheme 19

1. Disconnect the rear heater-A/C control panel-unit 14P connector.
2. Disconnect climate control unit connector A (16P).
3. Check for continuity between the No. 1 terminal of the rear heater-A/C control panel-unit 14P connector and the No. 1 terminal of climate control unit connector A (16P). Is there continuity? YES - Go to step 4. NO - Repair open in the wire between the rear heater-A/C control panel-unit and the climate control unit.
4. Check for continuity between the No. 1 terminal of the rear heater-A/C control panel-unit 14P connector and body ground. Is there continuity? YES - Repair short to body ground in the wire between the rear heater-A/C control panel-unit and the climate control unit. NO - Check for loose wires or poor connections at the rear heater-A/C control panel-unit 14P connector and at climate control unit connector A (16P). If the connections are good, substitute a known-good rear heater-A/C control panel-unit, and recheck. If the problem still exists, replace the climate control unit.

Scheme 20

Scheme 21

Scheme 22

Scheme 23

1. Check the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box. Is the fuse OK? YES - Go to step 2. NO - Replace the fuse, and recheck.
2. Disconnect the rear mode control motor 7P connector.
3. Turn the ignition switch ON (II).
4. Measure the voltage between the No. 1 terminal of the rear mode control motor 7P connector and body ground. Is there battery voltage? YES - Go to step 5. NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the rear mode control motor.
5. Turn the ignition switch OFF.
6. Test the rear mode control motor (see «REAR MODE CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). Is the rear mode control motor OK? YES - Go to step 7. NO - Go to step 12 .
7. Disconnect the rear heater-A/C control panel-unit 14P connector.
8. Check for continuity between the No. 2 and No. 8 terminals of the rear heater-A/C control panel-unit 14P connector and body ground individually. Is there continuity? YES - Repair short to body ground in the wire(s) between the rear heater-A/C control panel-unit and the rear mode control motor. NO - Go to step 9.
9. Turn the ignition switch ON (II), and check the same terminals for voltage. Is there any voltage? YES - Repair short to power in the wire(s) between the rear heater-A/C control panel-unit and the rear mode control motor. This short may also damage the rear heater-A/C control panel-unit. Repair the short to power before replacing the rear heater-A/C control panel-unit. NO - Go to step 10.
10. Turn the ignition switch OFF.
11. Check for continuity between the following terminals of the rear heater-A/C control panel-unit 14P connector and the rear mode control motor 7P connector. REAR HEATER-A/C CONTROL PANEL-UNIT 14P AND REAR MODE CONTROL MOTOR 7P 14P 7P No. 2 No. 7 No. 8 No. 5 Is there continuity? YES - Check for loose wires or poor connections at the rear heater-A/C control panel-unit 14P connector and at rear mode control motor 7P connector. If the connections are good, substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit. NO - Repair open in the wire(s) between the rear heater-A/C control panel-unit and the rear mode control motor.
12. Remove the rear mode control motor (see «REAR MODE CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ).
13. Check the rear mode control linkage and door for smooth movement. Do the rear mode control linkage and door move smoothly? YES - Replace the rear mode control motor. NO - Repair the rear mode control linkage or door.

Scheme 24

Scheme 25

1. Check the No. 3 (7.5 A) fuse in the driver's under-dash fuse/relay box. Is the fuse OK? YES - Go to step 2. NO - Replace the fuse, and recheck.
2. Disconnect the rear heater-A/C control panel-unit 14P connector.
3. Turn the ignition switch ON (II).
4. Measure the voltage between the No. 14 terminal of the rear heater-A/C control panel-unit 14P connector and body ground. Is there battery voltage? YES - Go to step 5. NO - Repair open in the wire between the No. 3 fuse in the driver's under-dash fuse/relay box and the rear heater-A/C control panel-unit.
5. Turn the ignition switch OFF.
6. Check for continuity between the No. 4 terminal of the rear heater-A/C control panel-unit 14P connector and body ground. Is there continuity? YES - Check for loose wires or poor connections at the rear heater-A/C control panel-unit 14P connector. If the connections are good, substitute a known-good rear heater-A/C control panel-unit, and recheck. If the symptom/indication goes away, replace the original rear heater-A/C control panel-unit. NO - Check for an open in the wire between the rear heater-A/C control panel-unit and body ground. If the wire is OK, check for poor ground at G501.

Scheme 26

1. Disconnect the 7P connector from the rear air mix control motor. NOTE: Incorrectly applying power and ground to the rear air mix control motor will damage it. Follow the instructions carefully.
2. Connect battery power to the No. 1 terminal of the rear air mix control motor, and ground the No. 2 terminal; the rear air mix control motor should run, and stop at Max Hot. If it doesn't, reverse the connections; the rear air mix control motor should run, and stop at Max Cool.
3. If the rear air mix control motor did not run in step 2 , remove it, then check the rear air mix control linkage and door for smooth movement. If the linkage and the door move smoothly, replace the rear air mix control motor. If the linkage or the door sticks or binds, repair them as needed. If the rear air mix control motor runs smoothly, go to step 4.
4. Measure the resistance between the No. 5 and No. 7 terminals. It should be between 4.2 to 7.8 kohms
5. Reconnect the rear air mix control motor 7P connector, then turn the ignition switch ON (II).
6. Using the backprobe set, measure the voltage between the No. 3 and No. 5 terminals. Max Cool-about 4.2 V Max Hot-about 0.7 V
7. If either the resistance or voltage readings are not as specified, replace the rear air mix control motor.

Scheme 27

1. Remove the center console (see «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
2. Disconnect the 7P connector (A) from the rear air mix control motor (B). Remove the self-tapping screws and the rear air mix control motor from the rear heater-A/C unit.
3. Install the motor in the reverse order of removal. Make sure the pin on the motor is properly engaged with the linkage. After installation, make sure the motor runs smoothly.

Scheme 28

1. Disconnect the 7P connector from the rear mode control motor. NOTE: Incorrectly applying power and ground to the rear mode control motor will damage it. Follow the instructions carefully.
2. Connect battery power to the No. 1 terminal of the rear mode control motor, and ground the No. 5 and No. 7 terminals; the rear mode control motor should run smoothly. To avoid damaging the rear mode control motor, do not reverse power and ground. Disconnect the No. 5 or No. 7 terminal from ground; the rear mode control motor should stop at Vent or Heat. Don't cycle the rear mode control motor for a long time.
3. If the rear mode control motor did not run in step 2 , remove it, then check the rear mode control linkage and door for smooth movement. If the linkage and door move smoothly, replace the rear mode control motor. If the linkage or door sticks or binds, repair them as needed.

Scheme 29

1. Remove the center console (see «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) )
2. Disconnect the 7P connector (A) from the rear mode control motor (B). Remove the rod (C) of the rear mode control motor from the rear mode control linkage (D). Remove the self-tapping screws and the rear mode control motor from the rear heater-A/C unit.
3. Install the motor in the reverse order of removal. After installation, make sure the motor runs smoothly.

Scheme 30

Scheme 31

1. Remove the driver's console side trim (see step 5 in «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
2. Disconnect the 4P connector from the rear power transistor.
3. Measure the resistance between the No. 1 and No. 2 terminals of the rear power transistor. It should be about 1.4-1.5 kohms. If the resistance is within the specifications, go to step 4. If the resistance is not within the specifications, replace the rear power transistor.
4. Carefully release the lock tab on the No. 4 terminal (WHT/RED) (A) in the 4P connector, then remove the terminal and insulate it from body ground.
5. Reconnect the 4P connector to the rear power transistor.
6. Supply 12 V to the No. 4 cavity with a jumper wire.
7. Turn the ignition switch ON (II), and check that the rear blower motor runs. If the rear blower motor does not run, replace the rear power transistor. If the rear blower motor runs, the rear power transistor is OK.

Scheme 32

1. Remove the console rear trim (see step 6 in «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
2. Remove the self-tapping screws and the rear heater-A/C control panel-unit (A) from the console rear trim (B).
3. Install the control unit in the reverse order of removal. After installation, operate the control unit controls to see if they work properly.
4. Run the self-diagnostic function to confirm that there are no problems in the system.

Scheme 33

1. Remove the center console (see «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
2. Disconnect the 2P connector (A) from the rear blower motor (B), then remove the self-tapping screw and the cover (C). Turn the rear blower motor clockwise to the stop, and remove it.
3. Install the motor in the reverse order of removal.

Scheme 34

Scheme 35

1. When the engine is cool, drain the engine coolant from the radiator (see «COOLANT REPLACEMENT»(/acura/mdx/i-2000-2006/remont/cooling-system-mechanical/#cooling-system) ).
2. Remove the center console (see «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
3. Slide the hose clamps (A) back, then disconnect the inlet heater hose (B) and the outlet heater hose (C) from the rear heater core. Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on the electrical parts or the painted surfaces. If any coolant spills, rinse it off immediately.
4. Remove the self-tapping screws and the clamps (A). Carefully pull out the rear heater core (B) so you don't bend the inlet and outlet pipes.
5. Install the heater core in the reverse order of removal, and note these items: Do not interchange the inlet and outlet heater hoses, and install the hose clamps securely. Refill the cooling system with engine coolant (see «COOLANT CHECK»(/acura/mdx/i-2000-2006/remont/cooling-system-mechanical/#cooling-system) ). Make sure that there is no coolant leakage.

Rear Heater-A/C Unit Removal and Installation

SRS components are located in this area. Review the SRS component locations for the appropriate year

1. '03 model (see «2003 MODEL»(/acura/mdx/i-2000-2006/remont/airbag/#srs-supplemental-restraint-system) )
2. '04-06 models (see «2004-2006 MODELS»(/acura/mdx/i-2000-2006/remont/airbag/#srs-supplemental-restraint-system) )

Also review the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) in the SRS section before performing repairs or service.

Scheme 36

Scheme 37

Scheme 38

Scheme 39

1. When the engine is cool, drain the engine coolant from the radiator (see «COOLANT REPLACEMENT»(/acura/mdx/i-2000-2006/remont/cooling-system-mechanical/#cooling-system) ).
2. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
3. Remove the center console (see «CENTER CONSOLE REMOVAL/INSTALLATION»(/acura/mdx/i-2000-2006/remont/gauges-instrument-panels/#consoles__center-console-removalinstallation) ).
4. Remove the shift cable from the shift lever (see «SHIFT CABLE REPLACEMENT»(/acura/mdx/i-2000-2006/remont/automatic-trans/#automatic-transmission) ).
5. Disconnect the connectors (A) from the shift lock solenoid, the mode switch, the front stereo amplifier, and the rear blower motor relay, then remove the wire harness clips (B). Remove the bolts and the shift lever bracket (C).
6. Slide the hose clamps (A) back, then disconnect the inlet heater hose (B) and the outlet heater hose (C) from the rear heater core. Engine coolant will run out when the hoses are disconnected; drain it into a clean drip pan. Be sure not to let coolant spill on the electrical parts, the carpet, or the painted surfaces. If any coolant spills, rinse it off immediately.
7. Remove the nuts at the rear evaporator suction line (A) and the receiver line (B) connections.
8. Disconnect the connectors from the rear blower motor (A), the rear power transistor (B), the rear air mix control motor (C), and the rear mode control motor (D), then remove the wire harness clips (E). Remove the mounting bolts and the rear heater-A/C unit (F). Plug or cap the lines immediately after disconnecting them to avoid moisture and dust contamination.
9. Install the unit in the reverse order of removal, and note these items: If you're installing a new rear evaporator, add refrigerant oil (DENSO ND-OIL 8) (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ). Replace the O-rings with new ones at each fitting, and apply a thin coat of refrigerant oil before installing them. Be sure to use the current O-rings for HFC-134a (R-134a) to avoid leakage. Immediately after using the oil, replace the cap on the container, and seal it to avoid moisture absorption. Do not spill refrigerant oil on the vehicle; it may damage the paint; if the refrigerant oil contacts the paint, wash it off immediately. Do not interchange the inlet and outlet heater hoses, and install the hose clamps securely. Refill the cooling system with engine coolant (see «COOLANT CHECK»(/acura/mdx/i-2000-2006/remont/cooling-system-mechanical/#cooling-system) ). Make sure that there is no coolant leakage. Charge the system (see «SYSTEM CHARGING»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__system-charging) ).

Rear Heater-A/C Unit Component Replacement

Note. The rear blower motor (A), the rear heater core (B), the blower screen (C), the rear power transistor (D), the rear air mix control motor (E), the rear mode control motor (F), and the rear expansion valve (G) can be replaced without removing the rear heater-A/C unit.

Scheme 40

1. Remove the self-tapping screw and the clamp (H), then remove the bolts and the rear evaporator lines (I) with the rear expansion valve. If necessary, remove the rear expansion valve. Use a second wrench to hold the other fitting on the valve so the rear evaporator lines won't twist. Leave the first fitting loosely connected so you can use it to hold the valve while you loosen the second fitting.
2. If necessary, remove the rear blower motor (see «REAR BLOWER MOTOR REPLACEMENT»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ), the rear heater core (see «REAR HEATER CORE REPLACEMENT»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ), the blower screen, the rear power transistor, the rear air mix control motor (see «REAR AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ), and the rear mode control motor (see «REAR MODE CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ).
3. Remove the self-tapping screws and the lower housing (J). Remove the self-tapping screws, and carefully separate the left upper housing (K) from the right upper housing (L). Remove the rear evaporator core (M).
4. Reassemble the unit in the reverse order of disassembly, and note these items; Replace all O-rings with new ones at each fitting and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage. Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption. Make sure no air is leaking from the left upper housing and the right upper housing fitting and from the upper housings and the lower housing fitting. Install the capillary tube (N) directly against the outlet line, and wrap it with electrical tape (O). Before reassembly, make sure that the rear air mix control linkage and door move smoothly without binding. Before reassembly, make sure that the rear mode control linkage and door move smoothly without binding. After reassembly, make sure the rear air mix control motor runs smoothly (see «REAR AIR MIX CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). After reassembly, make sure the rear mode control motor runs smoothly (see «REAR MODE CONTROL MOTOR TEST»(/acura/mdx/i-2000-2006/remont/manual-hvac-system/#rear-air-conditioning) ). Make sure that there is no coolant leakage.

Scheme 41

Scheme 42

Scheme 43

Scheme 44

1. Recover the refrigerant with a recovery/recycling/charging station (see «REFRIGERANT RECOVERY»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__refrigerant-recovery) ).
2. Disconnect the rear A/C suction line (A) and receiver line (B) at the front evaporator.
3. Remove the screws from the two clamps (A) along the engine compartment bulkhead, then free the rear A/C lines (B) from the clamps.
4. Raise the vehicle on a hoist, and remove the left front wheel.
5. Remove the 6 mm flange nut from the A/C line clamps/bracket (A) above the steering rack on the driver's side. Remove the screw from the A/C line clamp (B) next to the steering rack.
6. Disconnect the rear A/C suction line (A) and receiver line (B) at the rear evaporator connections.
7. Free the rear A/C lines from the bracket above the steering gearbox.
8. Remove the rear A/C lines (receiver line, then suction line) from the top of the engine compartment. If necessary, bend the rear A/C lines as needed for removal. NOTE: Be careful not to bend or snag the brake lines, wire harness, or other components when removing the rear A/C lines.

Installation

Note. Take care not to bend the replacement A/C lines during installation. Be careful not to bend or snag the brake lines, wire harness, or other components when installing the replacement A/C lines.

Scheme 45

Scheme 46

Scheme 47

Scheme 48

1. Route the lower replacement rear A/C lines (suction line, then receiver line) from the top of the engine compartment down to the rear evaporator connections. Do not connect the lines yet.
2. Route the upper replacement A/C lines along the engine compartment bulkhead, and loosely connect the upper lines (A) to the lower lines (B). Do not tighten the connections yet.
3. Install the A/C line bracket (A) on the lower replacement A/C line. Slide the bracket onto its mounting stud (B), but do not install the 6 mm flange nut yet.
4. Apply a few drops of refrigerant oil to the connections, then connect the lower lines (A) to the rear evaporator lines (B). Do not tighten the connections yet.
5. Install the screw in the A/C line clamp (next to the steering gearbox) on the lower A/C lines.
6. Install the 6 mm flange nut onto the A/C line clamp/bracket mounting stud, and tighten it.
7. Tighten the lower A/C lines at the rear evaporator connections.
8. Apply a few drops of refrigerant oil to the connections, then connect the rear A/C suction line (A) and receiver line (B) to the front evaporator lines. Do not tighten the connections yet.
9. Install the screws into the two A/C line clamps along the engine compartment bulkhead.
10. Tighten the upper-A/C-line-to-front-evaporator connections.
11. Tighten the upper-to-lower A/C line connections.
12. Add refrigerant oil (see «A/C REFRIGERANT OIL REPLACEMENT»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__ac-refrigerant-oil-replacement) ).
13. Charge the system (see «SYSTEM CHARGING»(/acura/mdx/i-2000-2006/remont/automatic-hvac-system/#climate-control__system-charging) ).
14. Reinstall the left front wheel.

See also:
• POWER RELAY TEST
• CENTER CONSOLE REMOVAL/INSTALLATION
• COOLANT REPLACEMENT
• 2003 MODEL
• REFRIGERANT RECOVERY
• SHIFT CABLE REPLACEMENT
• A/C REFRIGERANT OIL REPLACEMENT
• SYSTEM CHARGING
• DTC1: A PROBLEM IN THE REAR BLOWER MOTOR CIRCUIT
• DTC 2: A PROBLEM IN THE REAR AIR MIX CONTROL LINKAGE, DOOR, OR MOTOR