Home ReviewsRefund
Home/Chevrolet/Colorado/Chevrolet Colorado I (2004-2012)/Repair manual/Manual HVAC System/Heating, Ventilation, and Air Conditioning
Contents Wiring diagrams Section: Manual HVAC System All sections

Heating, Ventilation, and Air Conditioning Chevrolet Colorado I

Manual HVAC System 10 illustrations ~8330 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
A/C Compressor Mounting Bolt50 N.m37 lb ft
A/C Evaporator and Blower Module Shield Screws2.2 N.m19 lb in
A/C Refrigerant Pressure Sensor4.8 N.m42 lb in
Air Distributor Duct Mounting Screw1.9 N.m17 lb in
Air Inlet Assembly Mounting Stud4.5 N.m40 lb in
Air Outlet Assembly Retaining Screw2.5 N.m22 lb in
Blower Motor and Fan Assembly Mounting Screw1.9 N.m17 lb in
Blower Motor Relay Bracket Mounting Screw1.9 N.m17 lb in
Blower Motor Resistor Mounting Screw1.9 N.m17 lb in
Compressor Discharge Hose to Condenser Fitting28 N.m21 lb ft
Compressor Pressure Relief Valve9 N.m80 lb in
Compressor Suction and Discharge Hose to Compressor33 N.m24 lb ft
Compressor Suction Hose to TXV48 N.m35 lb ft
Condenser Insulator Retaining Screw1.9 N.m17 lb in
Evaporator Case Section to Blower Case Section Retaining Screw1.9 N.m17 lb in
Evaporator Tube to Condenser Fitting10 N.m2.25 lb ft
Floor Air Outlet Mounting Screw1.9 N.m17 lb in
Heater Core Access Cover Screw1.9 N.m17 lb in
Heater Inlet and Outlet Hoses Bracket Bolt25 N.m18 lb ft
Heater Inlet Hose Fitting at Intake Manifold23.5 N.m17 lb ft
Heater Outlet Hose Bracket Bolt25 N.m18 lb ft
Heater/Vent Module Mounting Nut4.5 N.m40 lb in
Heater/Vent Module Mounting Screw4.5 N.m40 lb in
Heater/Vent Module Mounting Stud4.5 N.m40 lb in
Intermediate Bracket Bolts10 N.m88 lb in
Knee Bolster Bracket Nuts5.5 N.m49 lb in
Receiver Drier Clamp Screw10 N.m88 lb in

Fastener Tightening Specifications

Compressor Suction Screen and Tool Selection Specifications

Part NumberScreen SizeFitting ID Application Range
J-44551-4010.03 mm (0.395 in)9.75-9.96 mm (0.384-0.392 in)
J-44551-6011.96 mm (0.471 in)11.68-11.89 mm (0.460-0.468 in)
J-44551-7012.50 mm (0.492 in)12.22-12.42 mm (0.481-0.489 in)
J-44551-8012.70 mm (0.500 in)12.42-12.62 mm (0.489-0.497 in)
J-44551-1012.95 mm (0.510 in)12.67-12.88 mm (0.499-0.507 in)
J-44551-2014.02 mm (0.552 in)13.74-13.94 mm (0.541-0.549 in)
J-44551-3015.11 mm (0.595 in)14.83-15.04 mm (0.584-0.592 in)
J-44551-900.600 in (15.24 mm)14.96-15.16 mm (0.589-0.597 in)

Compressor Suction Screen and Tool Selection Specifications

Refrigerant System Capacities

ApplicationSpecification
MetricEnglish
PAG Oil GM P/N 12378526 (Canadian P/N 88900060)
Receiver Dryer Replacement23 ml*0.8 oz*
*Add PAG oil equal amount of oil drained from the old receiver dryer plus the specified additional amount.
Compressor Replacement35 ml 11.2 oz 1
The Denso service compressor is precharged with 119 ml (4 oz) of PAG oil.
Condenser Replacement15 ml 10.5 oz 1
Evaporator Replacement44 ml 11.5 oz 1
Total System Oil Capacity119 ml4 oz
R-134a
Refrigerant Charge0.73 kg1.6 lb
1 If more than the specified amount of oil was drained from a component, add the equal amount of oil drained.

Refrigerant System Capacities

The Heating, Ventilation and Air Conditioning (HVAC) system is divided into 2 separate sections. The first, Heating, Ventilation and Air Conditioning, has all procedures that pertain to a HVAC component or function that is not specifically associated with the manual control system. The second, HVAC Systems - Manual, has all procedures specific to the Manual control system.

Begin the system diagnosis with the Diagnostic System Check - Vehicle .

The Diagnostic System Check will provide the identification of the control modules which command the system.

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

Review the Description and Operation information to help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. The HVAC Description and Operation information is divided into

  1. «Air Delivery Description and Operation»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#hvac-system-manual__air-delivery-description-and-operation)
  2. «Air Temperature Description and Operation»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#hvac-system-manual__air-temperature-description-and-operation)

The Air Delivery Description and Operation contains the following topics

  1. HVAC Control Components
  2. Air Speed
  3. Air Distribution
  4. Recirculation Operation

The Air temperature Description and Operation contains the following topics

  1. HVAC Control Components
  2. Heating and A/C Operation
  3. Engine Coolant
  4. A/C Cycle

Leak Testing

Tools Required

  1. J 39400-A Halogen Leak Detector. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  2. J 41447 R-134A A/C Tracer Dye-Box of 24. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  3. J 42220 Universal 12V Leak Detection Lamp
  4. J 43872 Fluorescent Dye Cleaner. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  5. J 46297 A/C Dye Injector Kit. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  6. J 46297-12 Replacement Dye Cartridges. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

Refrigerant Leak Testing

IMPORTANTGeneral Motors vehicles are now manufactured with fluorescent dye installed directly into the air conditioning (A/C) system.

The fluorescent dye mixes and flows with the polyalkylene glycol (PAG) oil throughout the refrigerant system.

Verifying some passive leaks may require using the J 39400-A , even though the A/C system contains fluorescent dye. See Special Tools .

The only time that adding additional fluorescent dye is required is after flushing the A/C system.

Fluorescent Leak Detector

Fluorescent dye will assist in locating any leaks in the A/C system.

  1. Condensation on the evaporator core or the refrigerant lines may wash the PAG oil and fluorescent dye away from the actual leak. Condensation may also carry dye through the HVAC module drain.
  2. Leaks in the A/C system will be indicated in a light green or yellow color when using the leak detection lamp. Use the leak detection lamp in the following areas: All fittings or connections that use seal washers or O-rings All of the A/C components The A/C compressor shaft seal The A/C hoses and pressure switches The HVAC module drain tube, if the evaporator core is suspected of leaking The service port sealing caps The sealing cap is the primary seal for the service ports.
  3. Follow the instructions supplied with the J 42220 .
  4. To prevent false diagnosis in the future, thoroughly clean the residual dye from any area where leaks were found. Use a rag and the approved J 43872 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

Fluorescent Dye Injection

  1. Not all of the fluorescent dyes are compatible with PAG oil. Some types of dye decrease the oil viscosity or may chemically react with the oil.
  2. R-134A leak detection dye requires time to work. Depending upon the leak rate, a leak may not become visible for between 15 minutes and 7 days.
  3. To prevent false diagnosis, thoroughly clean any residual dye from the service port with a rag and the approved fluorescent dye cleaner J 43872 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

Halogen Leak Detector

CAUTIONDo not operate the detector in a combustible atmosphere since its sensor operates at high temperatures or personal injury and/or damage to the equipment may result.

Ensure that the vehicle has at least 0.45 kg (1 lb) of refrigerant in the A/C refrigeration system in order to perform a leak test. Refer to Refrigerant Recovery and Recharging (Non HP2) for recharging the A/C system.

IMPORTANTHalogen leak detectors are sensitive to the following items: Windshield washing solutions Many solvents and cleaners Some adhesives used in the vehicle

Clean and dry all surfaces in order to prevent a false warning. Liquids will damage the detector.

IMPORTANTFollow a continuous path in order to ensure that you will not miss any possible leaks. Test all areas of the system for leaks.

Follow the instructions supplied with the J 39400-A . See Special Tools .

Air Conditioning (A/C) System Performance Test

This test measures the operating efficiency of the A/C system under the following conditions

  1. The current ambient air temperature
  2. The current relative humidity
  3. The high side pressure of the A/C system
  4. The low side pressure of the A/C system
  5. The temperature of the air being discharged into the passenger compartment

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 1: This step determines if the A/C system has at least the minimum refrigerant charge required to operate the system without damage.
  2. 2: This step measures the performance of the A/C system.
  3. 3: This step is to allow for vehicle variations as well as high ambient temperatures.
StepActionValuesYesNo
IMPORTANT: The ambient air temperature must be at least 16°C (60°F). Do not induce additional air flow across the front of the vehicle during the test. If you were sent here from a DTC diagnostic table, clear the DTC upon completion of this test.
1Park the vehicle inside or in the shade. Open the windows in order to ventilate the interior of the vehicle. If the A/C system was operating, allow the A/C system to equalize for about 2 minutes. Turn OFF the ignition. Install the J 43600 . See Special Tools . Record the ambient air temperature displayed on the J 43600 . See Special Tools . Record the low and high side STATIC pressure readings. Are both the low side and high side pressures within the specified value?More than 16°C (60°F) - 345 kPa (50 psi) More than 24°C (75°F) - 483 kPa (70 psi) More than 33°C (90°F) - 690 kPa (100 psi)Go to Step 2Go to Leak Testing
2IMPORTANT: Record the relative humidity and the ambient air temperature at the time of the test. Close the vehicle doors and windows. Open the drivers door window 12.7-15.2 cm (5-6 inches). Select the following HVAC control settings: The A/C is ON The coldest temperature setting The maximum blower speed Recirculation mode The I/P panel outlet mode All I/P panel outlets are OPEN Install the temperature probes of the J 43600 in the left and right center panel air outlets. See Special Tools . Apply the parking brake. Place the transaxle/transmission in one of the following positions: PARK (Automatic) NEUTRAL (Manual) Start the engine. Operate the A/C system for 5 minutes. Inspect A/C components for the following conditions: Abnormal frost areas Unusual noises IMPORTANT: Press the RESET button, before using the print function of the J 43600 . See Special Tools . Print the following information: The panel outlet air temperatures The low-side pressure The high-side pressure Compare the low and high side pressures and the panel output temperatures to the A/C performance table below. Does all the data recorded fall within the specified ranges of the A/C performance table?Go to Step 8Go to Step 3
3If the pressures and temperatures recorded do not fall within the specified ranges: Continue to operate the A/C system for an additional 5 minutes. RESET the J 43600 and record the pressures and temperatures again. See Special Tools . Compare the low and high side pressures and the panel output temperature to the A/C performance table. Does all the data recorded fall within the specified ranges of the A/C performance table?Go to Step 8Go to Step 4
4Do the high and low side pressures fall within the specified ranges, but the panel outlet temperatures do not?Go to Air Conditioning (A/C) Diagnostics - Pressure Zone AGo to Step 5
5Is the low side pressure greater than the specified range, but the high side pressure within or less than the specified range?Go to Air Conditioning (A/C) Diagnostics - Pressure Zone BGo to Step 6
6Are the low and high side pressures both greater than the specified ranges?Go to Air Conditioning (A/C) Diagnostics - Pressure Zone CGo to Step 7
7Is the high side pressure greater than the specified range, but the low side pressure is within or less than the specified range?Go to Air Conditioning (A/C) Diagnostics - Pressure Zone DGo to Step 8
8Operate the system in order to verify the test results. Did you find the same results?System OKGo to Symptoms - HVAC Systems - Manual
IMPORTANT
The ambient air temperature must be at least 16°C (60°F). Do not induce additional air flow across the front of the vehicle during the test. If you were sent here from a DTC diagnostic table, clear the DTC upon completion of this test.
IMPORTANT
Record the relative humidity and the ambient air temperature at the time of the test.
IMPORTANT
Press the RESET button, before using the print function of the J 43600 . See Special Tools .

Air Conditioning (A/C) System Performance Test

Ambient TemperatureRelative HumidityLow Side Service Port PressureHigh Side Service Port PressureMaximum Left Center Discharge Air Temperature
13-18°C (55-65°F)0-100%165-289 kPa (24-42 psi)530-847 kPa (77-123 psi)12°C (52°F)
19-24°C (66-75°F)Below 40%151-234 kPa (22-34 psi)771-1129 kPa (112-164 psi)10°C (50°F)
Above 40%172-2891 kPa (25-42 psi)771-1157 kPa (112-168 psi)13°C (55°F)
25-29°C (76-85°F)Below 35%158-241 kPa (23-35 psi)1040-1371 kPa (151-199 psi)13°C (54°F)
35-50%186-254 kPa (27-37 psi)1047-1391 kPa (152-202 psi)13°C (55°F)
Above 50%206-282 kPa (30-41 psi)1061-1419 kPa (154-206 psi)15°C (59°F)
30-35°C (86-95°F)Below 30%186-261 kPa (27-38 psi)1260-1639 kPa (183-238 psi)15°C (59°F)
30-50%192-261 kPa (28-38 psi)1281-1681 kPa (186-244 psi)17°C (61°F)
Above 50%213-275 kPa (31-40 psi)1309-1743 kPa (190-253 psi)18°C (63°F)
36-41°C (96-105°F)Below 20%213-282 kPa (31-41 psi)1522-1887 kPa (221-274 psi)18°C (64°F)
20-40%213-275 kPa (31-40 psi)1543-1942 kPa (224-282 psi)18°C (64°F)
Above 40%220-268 kPa (32-39 psi)1577-1998 kPa (229-290 psi)19°C (66°F)
42-46°C (106-115°F)Below 20%248-310 kPa (36-45 psi)1777-2122 kPa (258-308 psi)20°C (68°F)
Above 20%248-289 kPa (36-42 psi)1812-2177 kPa (263-316 psi)20°C (68°F)
47-49°C (116-120°F)Below 30%368-316 kPa (39-46 psi)2039-2377 kPa (296-345 psi)23°C (73°F)

A/C Performance Table

Scheme 1

Scheme 1
Scheme 1

Air Conditioning (A/C) Diagnostics - Pressure Zone A

StepActionValueYesNo
DEFINITION: The high and low side pressures may be normal or slightly less than normal. Air Delivery Concern Slight Refrigerant Under Charge Refrigerant Contamination
1Were you sent here from the A/C System Performance Test?Go to Step 2Go to Air Conditioning (A/C) System Performance Test
2Refer to the instrument panel outlet air temperatures recorded during the A/C system performance test. Does the discharge air temperature between the right and left center instrument panel outlets vary by more than 1-2°C (2-3°F)?Go to Step 7Go to Step 3
3Did the customer mention that the A/C system output temperatures are good at first, but then turn warm during extended drives?Go to Step 4Go to Step 5
4Increase engine speed to 2,000 RPM. During extended operation of the A/C system, does the low side pressure decrease, possibly accompanied by heavy frost on the liquid line between the expansion device and the evaporator?Go to Air Conditioning (A/C) Diagnostics - Pressure Zone DGo to Step 5
5Refer to the pressures recorded during the A/C system performance test. Inspect for the following conditions: CAUTION: Refer to Moving Parts and Hot Surfaces Caution . The high side pressure is slightly greater than the specified pressure ranges but still within Zone A on the A/C Pressure-Zone Classification Chart in the A/C System Performance Test. Refer to Air Conditioning (A/C) System Performance Test . The discharge line is hot. The suction line is cool. Do the listed conditions exist?Go to Step 7Go to Step 6
6Refer to the pressures recorded during the A/C system performance test. Inspect for the following conditions: The low side pressure is slightly lower than the specified pressure ranges but still within Zone A on the A/C Pressure-Zone Classification Chart in the A/C System Performance Test. Refer to Air Conditioning (A/C) System Performance Test . The discharge line is warm-to-hot. The suction line is cool-to-warm. Do the listed conditions exist?Go to Step 8Go to Air Temperature Malfunction
7The A/C system may be undercharged. Leak test A/C system. Refer to Leak Testing . Recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 14
8The A/C system may be contaminated. View the information screen on J 43600 for detection of foreign gases in the A/C system. See Special Tools . Do foreign gases exist?Go to Step 9Go to Step 10
9Evacuate the A/C system to a scavenging tank. Refer to Refrigerant Recovery and Recharging (Non HP2) . Recharge the A/C system to specifications. Is the action complete?Go to Step 14
10The A/C system may contain too much moisture or air. Evacuate and recharge the A/C system to specifications. Refer to Refrigerant Recovery and Recharging (Non HP2) . Operate the A/C system and inspect the instrument panel outlet air temperatures. Refer to Air Conditioning (A/C) System Performance Test . Are the instrument panel outlet air temperatures within the specified ranges of the A/C Performance Test Table?Go to Step 15Go to Step 11
11The A/C system may contain too much refrigerant oil. IMPORTANT: Operate the A/C system on low, in order to enhance oil flow to the high side of the system. Operate the A/C system with the engine at idle speed and the blower speed on low for approximately 15 minutes. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Remove the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Drain and measure the refrigerant oil from the receiver dehydrator. Was more than the specified amount of refrigerant oil drained from the receiver?148 ml (5 oz)Go to Step 12Go to Step 13
12Reinstall the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Flush the A/C system. Refer to Flushing . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Are the actions complete?Go to Step 14
13Add the specified amount of refrigerant oil to the receiver dehydrator. Refer to Refrigerant System Capacities . Install the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Are the actions complete?Go to Step 14
14Record the low and high side pressures and the instrument panel outlet air temperature. Compare the instrument panel outlet air temperatures to those listed in the A/C System Performance Chart. Refer to Air Conditioning (A/C) System Performance Test . Are the high and low side pressures and instrument panel outlet air temperatures within specifications?Go to Step 15Go to Air Conditioning (A/C) System Performance Test
15Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Symptoms - HVAC Systems - Manual
IMPORTANT
Operate the A/C system on low, in order to enhance oil flow to the high side of the system.

Air Conditioning (A/C) Diagnostics - Pressure Zone A

Air Conditioning (A/C) Diagnostics - Pressure Zone B

StepActionYesNo
DEFINITION: The low side pressure is higher than normal and the high side pressure is lower than normal. Malfunctioning A/C Compressor Refrigerant Under Charge
1Were you sent here from the A/C System Performance Test?Go to Step 2Go to Air Conditioning (A/C) System Performance Test
2After continued operation of the A/C system, do the low and the high side pressures equalize or become static?Go to Step 5Go to Step 3
3Refer to the pressures recorded during the A/C System Performance Test. Inspect for the following conditions: CAUTION: Refer to Moving Parts and Hot Surfaces Caution . The low side pressure is equal to or greater than the specified pressure range of the A/C Performance Table. Refer to Air Conditioning (A/C) System Performance Test . The high side pressure is less than the specified pressure range of the A/C Performance Table. Refer to Air Conditioning (A/C) System Performance Test . The low side refrigerant line at the compressor feels cool-to-warm. The high side refrigerant line at the compressor feels warm-to-hot. Do the listed conditions exist?Go to Step 5Go to Step 4
4Refer to the pressures recorded during the A/C System Performance Test. Inspect for the following conditions: CAUTION: Refer to Moving Parts and Hot Surfaces Caution . The low side pressure is greater than the specified pressure range of the A/C Performance Table. Refer to Air Conditioning (A/C) System Performance Test . The high side pressure is less than the specified pressure range of the A/C Performance Table. Refer to Air Conditioning (A/C) System Performance Test . The low side refrigerant line at the compressor feels warm. The high side refrigerant line at the compressor feels warm-to-hot. Do the listed conditions exist?Go to Step 5Go to Air Conditioning (A/C) System Performance Test
5The A/C system has a low refrigerant charge. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 6
6After you perform the repairs, record the following: The low and the high side pressures The instrument panel outlet air temperature Compare the pressures and the temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test . Are the readings within the specified ranges found on the A/C Performance Chart?Go to Step 13Go to Step 7
7The A/C compressor is malfunctioning. Remove the expansion device and inspect for contamination. Refer to Thermal Expansion Valve Replacement . Did you find metal flakes on the expansion device?Go to Step 9Go to Step 8
8Inspect the expansion device for a brown, powdery residue indicating desiccant in the A/C system. Is a brown, powdery residue present?Go to Step 11Go to Step 12
9Remove the suction and the discharge lines from the compressor. Refer to Suction Hose Replacement (LLV, LLR) and to Discharge Hose Replacement (LLV, LLR) . Inspect for metal flake contamination at the line connections and the compressor ports. Is metal flake contamination present?Go to Step 10Go to Step 12
10Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement . Replace the thermal expansion valve. Refer to Thermal Expansion Valve Replacement . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 13
11Flush the A/C system. Refer to Flushing . Replace the thermal expansion valve. Refer to Thermal Expansion Valve Replacement . Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement . Replace the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 13
12Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 13
13Operate the system in order to verify the repair Did you find and correct the condition?System OKGo to Symptoms - HVAC Systems - Manual

Air Conditioning (A/C) Diagnostics - Pressure Zone B

Air Conditioning (A/C) Diagnostics - Pressure Zone C

StepActionYesNo
DEFINITION: The low and the high side pressures are both higher than normal. Restricted Condenser Air Flow Cooling Fan Malfunction Expansion Device Malfunction
1Were you sent here from the A/C System Performance Test?Go to Step 2Go to Air Conditioning (A/C) System Performance Test
2Start the engine. Turn ON the A/C. Inspect for proper cooling fan operation. Refer to Cooling System Description and Operation . Are the cooling fans ON and operating properly?Go to Step 3Go to Step 5
3Visually inspect for the following conditions: Damaged condenser cooling fins Missing or misaligned air baffles Restricted air flow Do any of these conditions exist?Go to Step 4Go to Step 6
4Repair the air flow restriction. Is the action complete?Go to Step 9
5Repair the fault to the cooling fan operation. Refer to Diagnostic System Check - Vehicle . Is the repair complete?Go to Step 9
6CAUTION: Refer to Moving Parts and Hot Surfaces Caution . Feel the liquid line on both sides of the expansion device.Are the temperatures on both sides of the expansion device similar?Go to Step 7Go to Step 8
7Replace the damaged or faulty thermal expansion valve. Refer to Thermal Expansion Valve Replacement . Is the action complete?Go to Step 9
8Inspect for air in the refrigerant system, or the system is overcharged. Refer to the view screen on J 43600 ACR 2000 Air Conditioning Service Center for foreign gas content in the refrigerant. See Special Tools . Recover and recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the action complete?Go to Step 9
9Record the low and high side pressures and the instrument panel outlet air temperature after you have performed the repairs. Compare the pressures and the instrument panel outlet air temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test . Are the readings within the specified ranges listed in the A/C Performance Chart?Go to Step 10Go to Air Conditioning (A/C) System Performance Test
10Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Symptoms - HVAC Systems - Manual

Air Conditioning (A/C) Diagnostics - Pressure Zone C

Air Conditioning (A/C) Diagnostics - Pressure Zone D

StepActionYesNo
DEFINITION: The low side pressure is lower than normal and the high side pressure is higher than normal. A restriction in the A/C system Debris in the A/C system
1Were you sent here from the A/C System Performance Test?Go to Step 2Go to Air Conditioning (A/C) System Performance Test
2CAUTION: Refer to Moving Parts and Hot Surfaces Caution . Feel the liquid line before the expansion device.Is the liquid line cold before the expansion device?Go to Step 3Go to Step 8
3Feel along the surfaces of the following high side components: The compressor discharge hose The condenser The liquid line between the condenser and the expansion device Did you detect an abrupt drop in temperature along the surfaces of any of the listed components?Go to Step 7Go to Step 4
4Feel the liquid line at the expansion device location for extreme cold, possibly accompanied by heavy frost. Feel along the liquid line beyond the expansion device location for warm temperature. Is the liquid line extremely cold at the expansion device location and warm beyond the expansion device location?Go to Step 11Go to Step 5
5Feel along the surfaces of the following low side components: The evaporator inlet tube between the expansion device and the evaporator core The evaporator outlet tube between the evaporator core and the compressor suction hose The compressor suction hose Did you feel an abrupt temperature change along the surfaces of any of the listed components?Go to Step 7Go to Step 6
6Feel along the surfaces of the low and the high side components. The evaporator inlet tube between the expansion device and the evaporator core The evaporator outlet tube and the compressor The compressor suction hose The compressor discharge hose The condenser The evaporator inlet tube between the condenser and the expansion device Are the temperatures of these components only mildly warm?Go to Step 14Go to Step 8
7Recover the refrigerant. Refer to Refrigerant Recovery and Recharging (Non HP2) . Remove the restriction from the component, or replace the component which produced an abrupt temperature drop. Is the action complete?Go to Step 9
8Recover the refrigerant and evacuate the system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Record the weight of the recovered refrigerant. Compare the weight of the recovered refrigerant with the system capacity. Refer to Refrigerant System Capacities . Is the weight of the recovered refrigerant charge greater than 75% of the total system capacity?Go to Step 9Go to Step 10
9Recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the cooling performance improved?Go to Step 21Go to Step 10
10Leak test the system. Refer to Leak Testing . Repair any leaks. Is the action complete?Go to Step 21
11The expansion device is restricted. Replace the expansion device. Refer to Thermal Expansion Valve Replacement . If the expansion device was restricted, note the type of debris present. Are metal flakes present?Go to Step 12Go to Step 13
12Remove the suction line from the vehicle. Refer to Suction Hose Replacement (LLV, LLR) . Inspect the hose for debris by blowing shop air through one end of the hose while covering the other end with a shop towel. Observe the amount of debris collected in the shop towel. Did a large amount of debris collect in the shop towel?Go to Step 18Go to Step 20
13If the expansion device was restricted with a brown or black residue, perform the following procedure: Flush the A/C system. Refer to Flushing . Replace the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Are the actions complete?Go to Step 21
14Recover the refrigerant. Refer to Refrigerant Recovery and Recharging (Non HP2) . Disconnect the suction and the discharge lines from the compressor. Refer to Suction Hose Replacement (LLV, LLR) and to Discharge Hose Replacement (LLV, LLR) . Inspect for the presence of debris in the compressor suction port. Is debris present in the compressor suction port?Go to Step 15Go to Step 19
15Remove the debris from the suction port. Inspect the expansion device for damage or debris. Refer to Thermal Expansion Valve Replacement . Did you find evidence of damage or debris?Go to Step 17Go to Step 16
16If the expansion device does not show any signs of damage or debris, perform the following procedure: Remove the suction line from the vehicle. Refer to Suction Hose Replacement (LLV, LLR) . Inspect the hose for debris by blowing shop air through one end of the hose while covering the other end with a shop towel. Observe the amount of debris collected in the shop towel. Did a large amount of debris collect in the shop towel?Go to Step 18Go to Step 19
17Replace the expansion device. Refer to Thermal Expansion Valve Replacement . If the expansion device was restricted, observe the type of debris present. Are metal flakes present?Go to Step 12Go to Step 13
18If a large amount of debris was collected in the shop towel from the suction hose, replace the receiver dehydrator. Refer to Receiver Dehydrator Replacement . Is the action complete?Go to Step 19
19Install the suction and the discharge lines. Refer to Suction Hose Replacement (LLV, LLR) and Discharge Hose Replacement (LLV, LLR) . Is the action complete?Go to Step 21
20Install the suction and the discharge lines. Refer to Suction Hose Replacement (LLV, LLR) and to Discharge Hose Replacement (LLV, LLR) . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging (Non HP2) . Are the actions complete?Go to Step 21
21Record the low and the high side pressures and the instrument panel outlet air temperature after you perform the repairs. Compare the pressures and the instrument panel outlet air temperature to those listed in the A/C Performance Chart. Refer to Air Conditioning (A/C) System Performance Test . Are the readings within the specified ranges as shown on the A/C Performance Chart?Go to Step 22Go to Air Conditioning (A/C) System Performance Test
22Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Symptoms - HVAC Systems - Manual

Air Conditioning (A/C) Diagnostics - Pressure Zone D

Heating Performance Diagnostic

StepActionYesNo
DEFINITION: Heating system performance.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Air Temperature Malfunction
2Start the engine. Allow the engine to idle. Does the engine reach a normal operating temperature?Go to Step 3Go to Step 9
3CAUTION: Refer to Moving Parts and Hot Surfaces Caution . Allow the engine to idle. Select the FLOOR mode. Select the minimum blower speed. Select the warmest temperature setting. Feel the temperature of the inlet and outlet heater hoses at the heater core. Does the inlet heater hose feel warmer than the outlet heater hose?Go to Step 7Go to Step 4
4Install a thermometer into the center I/P PANEL air outlet. Secure a thermometer to the heater core outlet hose. Select the PANEL mode. Select the maximum blower speed. Select the warmest temperature setting. Record the temperature at the following locations: The center I/P PANEL air outlet The heater core outlet hose Compare the recorded temperatures. Are the two temperature readings about equal?Go to Step 5Go to Step 6
5Inspect and repair the following areas of the vehicle for cold air leaks: The cowl The recirculation door The HVAC module case Perform the necessary repairs. Are the repairs complete?Go to Step 10
6Inspect the temperature door operation. Perform any necessary repairs. Are the repairs complete?Go to Step 10
7Turn OFF the engine. Backflush the heater core. Start the engine. Select the FLOOR mode. Select the minimum blower speed. Select the warmest temperature setting. Feel the temperature of the inlet and outlet heater hoses at the heater core. Does the inlet heater hose feel warmer than the outlet heater hose?Go to Step 8Go to Step 10
8Replace the heater core. Refer to Heater Core Replacement . Is the repair complete?Go to Step 10
9Repair the low engine temperature concern. Refer to Engine Fails To Reach Normal Operating Temperature . Is the repair complete?Go to Step 10
10Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Heating Performance Diagnostic

Defrosting Insufficient

StepActionYesNo
DEFINITION: Time required to defrost the windshield is longer than usual.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Start the engine. Select the DEFROST mode. Select the maximum blower speed. Does sufficient air flow from the defroster outlets?Go to Step 3Go to Step 11
3Measure the engine operating temperature. Does engine reach normal operating temperature?Go to Step 4Go to Step 9
4Select the minimum blower speed. Select the warmest temperature setting. CAUTION: Refer to Moving Parts and Hot Surfaces Caution . Feel the temperature of the inlet and outlet hoses at the heater core. Does the inlet heater hose feel warmer than the outlet heater hose?Go to Step 12Go to Step 5
5Is the vehicle equipped with A/C?Go to Step 6Go to Step 14
6Test the operation of the A/C compressor clutch. Does the A/C compressor clutch engage?Go to Step 8Go to Step 7
7Repair the A/C compressor clutch. Refer to Air Conditioning Compressor Malfunction . Is the repair complete?Go to Step 15
8Perform the A/C system performance test. Refer to Air Conditioning (A/C) System Performance Test . Is the A/C system operating within the specifications?Go to Step 10Go to Step 13
9Repair the low engine temperature concern. Refer to Engine Fails To Reach Normal Operating Temperature . Is the repair complete?Go to Step 15
10Inspect for correct operation of the recirculation door. Is the recirculation door operating correctly?Go to Step 15Go to Step 14
11Repair the air delivery concern. Refer to Air Delivery Improper . Is the repair complete?Go to Step 15
12Repair the heating concern. Refer to Heating Performance Diagnostic . Is the repair complete?Go to Step 15
13Repair the A/C performance concern. Refer to Air Conditioning (A/C) System Performance Test . Is the repair complete?Go to Step 15
14Repair the recirculation door concern. Refer to Air Recirculation Malfunction . Is the repair complete?Go to Step 15
15Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Defrosting Insufficient

High or Low Mode Control Effort

StepActionYesNo
DEFINITION: The mode control operates with either too much or too little effort.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Is one of the following a concern of the customer: The mode control operates with little or no resistance. The HVAC outlet air is constant, regardless of the mode control setting. While driving the vehicle the mode control setting changes. Does the mode control operate too freely?Go to Step 3Go to Step 7
3With the ignition in the ON position: Select the HIGH blower motor speed. Cycle the mode control through all of the settings. Does the air outlet change through all of the modes?Go to Step 16Go to Step 4
4Inspect the connections of the mode control cable. Is the mode control cable disconnected from the mode actuator?Go to Step 15Go to Step 5
5Inspect the mode control cable and linkage, while operating the mode controls. Does the mode actuator move while operating the mode controls?Go to Step 21Go to Step 6
6Inspect the cable casing while operating the mode controls. Does the cable casing move, instead of the cable, while operating the mode controls?Go to Step 18Go to Step 21
7Inspect the HVAC control assembly for any debris or obstructions that would increase the effort to operate the mode controls. Are there any obstructions?Go to Step 20Go to Step 8
8Disconnect the mode control cable from the mode actuator. Operate the HVAC control assembly with the mode control cable disconnected. Does the HVAC control assembly bind now?Go to Step 10Go to Step 9
9With the mode control cable disconnected: Manually operate the mode actuator. Inspect for binding. Does the mode actuator bind with the cable disconnected?Go to Step 19Go to Step 10
10Disconnect the mode control cable from the HVAC control assembly. Operate the HVAC control assembly with the cable disconnected. Does the HVAC control assembly bind now?Go to Step 16Go to Step 11
11With the mode control cable disconnected at both ends: Extend the cable in both directions. Inspect the cable for binding. Does the mode control cable bind?Go to Step 17Go to Step 12
12Inspect the mode control cable for kinks or bends from incorrect routing. Repair the cable or routing as necessary. Does the mode cable still bind?Go to Step 17Go to Step 13
13Operate the HVAC control assembly with the mode control cable disconnected. Does the HVAC control assembly bind now?Go to Step 16Go to Step 14
14Reassemble the mode control system. Is the action complete?Go to Step 21
15Reconnect the mode control cable to the mode actuator linkage install the cable retainers. Is the action complete?Go to Step 21
16Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Is the repair complete?Go to Step 21
17Replace the mode control cable. Refer to Mode Control Cable Replacement . Is the repair complete?Go to Step 21
18Secure the mode control cable casing. Is the action complete?Go to Step 21
19Repair the binding door. Refer to the appropriate repair: Defroster Door Replacement Mode Door Replacement Recirculation Door Replacement Is the repair complete?Go to Step 21
20Remove the debris. Is the action complete?Go to Step 21
21Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

High or Low Mode Control Effort

High or Low Temperature Control Effort

StepActionYesNo
DEFINITION: The temperature control operates with either too much or too little effort.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Is one of the following a concern of the customer: The temperature control operates with little or no resistance. The HVAC outlet air temperature is constant, regardless of the temperature control setting. While driving the vehicle the temperature control setting changes. Does the temperature control operate too freely?Go to Step 3Go to Step 7
3Idle the engine at normal operating temperature. Cycle the temperature control from the coldest setting to the warmest setting. Does the temperature change from cold to hot?Go to Step 17Go to Step 4
4Inspect the connections of the temperature control cable. Is the temperature control cable disconnected from the temperature door?Go to Step 15Go to Step 5
5Inspect the temperature control cable and linkage at the temperature door, while operating the temperature controls. Does the temperature door move while operating the temperature controls?Go to Step 22Go to Step 6
6Inspect the cable casing while operating the temperature controls. Does the cable casing move, instead of the cable, while operating the temperature controls?Go to Step 19Go to Step 16
7Inspect the HVAC control assembly for any debris or obstructions that would increase the effort to operate the temperature controls. Are there any obstructions?Go to Step 21Go to Step 8
8Disconnect the temperature control cable from the temperature door. Operate the HVAC control assembly with the temperature control cable disconnected. Does the HVAC control assembly bind now?Go to Step 10Go to Step 9
9With the temperature control cable disconnected: Manually operate the temperature door. Inspect the door for binding. Does the temperature door bind with the cable disconnected?Go to Step 20Go to Step 10
10Disconnect the temperature control cable from the HVAC control assembly. Operate the HVAC control assembly with the cable disconnected. Does the HVAC control assembly bind now?Go to Step 17Go to Step 11
11With the temperature control cable disconnected at both ends: Extend the cable in both directions. Inspect the cable for binding. Does the temperature control cable bind?Go to Step 18Go to Step 12
12Inspect the temperature control cable for kinks or bends from incorrect routing. Repair the cable or routing as necessary. Does the temperature cable still bind?Go to Step 18Go to Step 13
13Operate the HVAC control assembly with the temperature control cable disconnected. Does the HVAC control assembly bind now?Go to Step 17Go to Step 14
14Reassemble the temperature control system. Is the action complete?Go to Step 22
15Reconnect the temperature control cable to the temperature door linkage install the cable retainers. Is the action complete?Go to Step 22
16Repair the lack of heating or lack of cooling condition. Refer to Diagnostic Starting Point - Heating, Ventilation and Air Conditioning . Is the action complete?Go to Step 22
17Replace the HVAC control assembly. Refer to Heater and Air Conditioning Control Replacement . Is the repair complete?Go to Step 22
18Replace the temperature control cable. Refer to Temperature Control Cable Replacement . Is the repair complete?Go to Step 22
19Secure the temperature control cable casing. Is the action complete?Go to Step 22
20Repair the binding door. Refer to Air Temperature Door Replacement . Is the repair complete?Go to Step 22
21Remove the debris. Is the action complete?Go to Step 22
22Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

High or Low Temperature Control Effort

Noise Diagnosis - Blower Motor

StepActionYesNo
DEFINITION: Noise originating from the blower motor.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Inspect the air inlet grille for debris. Is debris present?Go to Step 8Go to Step 3
3Sit inside the vehicle. Close the vehicle doors and windows. Turn ON the ignition, with the engine OFF. Cycle the blower motor through all of the speeds and modes in order to determine where and when the noise occurs. Is a noise evident during the blower operation?Go to Step 4Go to Step 11
4Inspect for excessive vibration at each blower motor speed by feeling the blower case. Is excess vibration present?Go to Step 6Go to Step 5
5Listen to the blower motor at each speed. Is the blower motor making a squeaking or chirping noise?Go to Step 9Go to Step 11
6Remove the blower motor. Refer to Blower Motor Replacement . Inspect the blower motor impeller for deposits of foreign material. Inspect the blower motor for deposits of foreign material. Did you find any foreign material on the blower motor or blower motor impeller?Go to Step 8Go to Step 7
7Inspect the blower motor for the following conditions: Cracked blades A loose impeller retainer Improper impeller alignment Did you find any of these conditions?Go to Step 9Go to Step 10
8Remove the foreign material. Is the action complete?Go to Step 10
9Replace the blower motor. Refer to Blower Motor Replacement . Is the repair complete?Go to Step 11
10Install the blower motor. Refer to Blower Motor Replacement . Is the action complete?Go to Step 11
11Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Noise Diagnosis - Blower Motor

Noise Diagnosis - Air Conditioning (A/C) System

StepActionYesNo
DEFINITION: Noise originating from the A/C compressor, drive belt or the A/C lines.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2A/C system noises can be generally categorized into three areas: Screeching, Squealing, Chirping noises Moaning noises Vibration/Rattle noises Start the engine. Ensure that the A/C is ON. Is a screeching, squealing noise heard when the A/C is engaged?Go to Step 3Go to Step 9
3With the engine OFF, inspect the drive belt for excessive wear. Refer to Drive Belt Falls Off and Excessive Wear Diagnosis for the 2.9L engine or Drive Belt Falls Off and Excessive Wear Diagnosis for the 3.7L engine. Is the drive belt excessively worn?Go to Step 18Go to Step 4
4Inspect the drive belt tension. Refer to Drive Belt Tensioner Diagnosis for the 2.9L engine or Drive Belt Tensioner Diagnosis for the 3.7L engine. Is the drive belt tension correct?Go to Step 5Go to Step 19
5Inspect the drive belt for excessive oil coverage. Is the drive belt covered with oil?Go to Step 17Go to Step 6
6Start the engine. Ensure that the A/C is ON. Inspect the compressor and the clutch. Is the A/C compressor locked up?Go to Step 24Go to Step 7
7Is the A/C compressor clutch slipping?Go to Step 23Go to Step 8
8CAUTION: Refer to MOVING PARTS AND HOT SURFACES CAUTION . Using a stethoscope, listen to the A/C compressor for any abnormal noises.Is the compressor causing an abnormal noise?Go to Step 15Go to Step 10
9Does a moaning noise exist when the A/C clutch is engaged?Go to Step 10Go to Step 12
10Listen to the A/C compressor components and mounting for noise concerns using a stethoscope. Are any of these components loose, damaged or excessively worn?Go to Step 20Go to Step 11
11Idle the engine. Engage the A/C compressor clutch. Using a stethoscope, move around the entire refrigerant plumbing system. Listening for any abnormal noises caused by a component of the A/C system touching another component. Are any of the A/C components grounding out and causing a vibration noise?Go to Step 22Go to Step 13
12Does a vibration or rattle noise exist when the A/C clutch is engaged?Go to Step 13Go to Step 14
13Does the noise stop when the A/C clutch is disengaged?Go to Step 15Go to Step 25
14Idle the engine in PARK with the A/C compressor clutch engaged. Using a stethoscope, move around the entire A/C system testing for any abnormal noises caused by a component. Do any of the A/C components cause an abnormal noise?Go to Step 21Go to Step 25
15Verify that the A/C system is properly charged. Refer to Refrigerant System Capacities . Is the A/C system properly charged?Go to Step 26Go to Step 16
16Recharge the A/C system to specification. Refer to Refrigerant Recovery and Recharging (Non HP2) . Is the abnormal compressor noise still present?Go to Step 24Go to Step 26
17Repair the oil leak. Refer to the appropriate repair procedure for the 2.9L or 3.7L engine. Is the repair complete?Go to Step 26
18Replace the drive belt. Refer to Drive Belt Replacement for the 2.9L engine or Drive Belt Replacement for the 3.7L engine. Is the replacement complete?Go to Step 26
19Replace the drive belt tensioner. Refer to Drive Belt Tensioner Replacement for the 2.9L engine or Drive Belt Tensioner Replacement for the 3.7L engine. Is the replacement complete?Go to Step 26
20Repair or replace the A/C compressor mounting component. Is the repair complete?Go to Step 26
21Repair or replace the component which is causing the moaning concern as needed. Is the repair complete?Go to Step 26
22Correctly route or insulate the A/C component. Is the repair complete?Go to Step 26
23Replace the A/C compressor clutch. Refer to Compressor Clutch Plate/Hub Assembly Replacement (LLV, LLR) . Is the repair complete?Go to Step 26
24Replace the A/C compressor. Refer to Air Conditioning Compressor Replacement . Is the repair complete?Go to Step 26
25The concern may be caused by an engine related component. Refer to Vibration Analysis - Engine . Did you find and correct the condition?Go to Step 26
26Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Noise Diagnosis - Air Conditioning (A/C) System

Noise Diagnosis - HVAC Module

StepActionYesNo
DEFINITION: Noise originating from the HVAC module.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Start the engine. Cycle through all of the following: Blower motor speeds HVAC modes Temperature control settings Determine the type of noise: Scrape, pop Tick/click, chirp or groaning Air rush/whistle Is a scrape or pop noise evident when selecting modes or temperature settings?Go to Step 6Go to Step 3
3Is a tick/click, chirping, groaning or scraping noise present, but decreases as blower motor speed is decreased?Go to Step 6Go to Step 4
4Is an air rush/whistle noise evident in all modes but not all temperature settings?Go to Step 6Go to Step 5
5Is an air rush/whistle noise evident only in defrost or floor mode?Go to Step 6Go to Step 6
6Remove the I/P assembly. Refer to Instrument Panel Assembly Replacement . Is the action complete?Go to Step 7
7Inspect the air flow doors for proper operation. Inspect the ducts for obstructions or foreign materials. Were any of these conditions found?Go to Step 10Go to Step 8
8Inspect the mode and temperature doors and seals for warping or cracking. Are the doors in normal condition?Go to Step 11Go to Step 9
9Replace the appropriate door and/or seals. Is the repair complete?Go to Step 11
10Remove any obstructions or foreign material found. Is the action complete?Go to Step 11
11Install the I/P assembly. Refer to Instrument Panel Assembly Replacement . Is the action complete?Go to Step 12
12Operate the system to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Noise Diagnosis - HVAC Module

Odor Diagnosis

StepActionYesNo
DEFINITION: Odor originating or noticed through the HVAC system.
1Were you sent here from Symptoms or another diagnostic table?Go to Step 2Go to Symptoms - HVAC Systems - Manual
2Sit inside the vehicle. Close all of the doors and windows. Start the engine. Allow the engine idle at normal operating temperature. Select the maximum blower speed. Select the PANEL air outlet mode. Select the coldest temperature setting. Cycle through all of the blower speeds, modes and temperatures to define what type of odor is present. Musty smell Coolant smell Oil smell Does the odor have a musty smell?Go to Step 3Go to Step 8
3Inspect the HVAC filter and the air inlet grille for debris. Is debris present?Go to Step 4Go to Step 5
4Remove any debris. Is the action complete?Go to Step 15
5Inspect for wet carpeting. Is the carpet wet?Go to Step 6Go to Step 14
6Inspect for the following conditions: Water leaks around the windshield Blockage of the HVAC module drain Leaks around the door seals Is a leak present?Go to Step 7Go to Step 14
7Repair the leak as necessary. Is the repair complete?Go to Step 15
8Does the odor have a coolant smell?Go to Step 9Go to Step 12
9Inspect the cooling system for leaks. Refer to Cooling System Leak Testing . Is a leak present?Go to Step 10Go to Step 12
10Inspect for coolant leaking inside the vehicle or for a film build-up on the windshield. Is the condition present?Go to Step 11Go to Step 15
11Replace the heater core. Refer to Heater Core Replacement . Is the repair complete?Go to Step 15
12Does the odor have an oily smell?Go to Step 13Go to Step 15
13Inspect the engine compartment for any leaks. Refer to the following procedures: Oil Leak Diagnosis for the 2.9L engine or Oil Leak Diagnosis for the 3.7L engine Fluid Leak Diagnosis for the 4L60-E/4L65-E automatic transmission Power Steering Fluid Leaks Repair any oil leaks. Is the repair complete?Go to Step 15
14A musty odor can be caused by mold or mildew build-up on the evaporator or the heater core or inside of the HVAC module. Refer to Odor Correction . Is the action complete?Go to Step 15
15Operate the system in order to verify the repair. Did you find and correct the condition?System OKGo to Step 2

Odor Diagnosis

Eliminating Air Conditioning Odor

Odors may be emitted from the air conditioning system primarily at start up in hot, humid climates. The following conditions may cause the odor

  1. Debris is present in the HVAC module.
  2. Microbial growth on the evaporator core

When the blower motor fan is turned on, the microbial growth may release an unpleasant musty odor into the passenger compartment. To remove odors of this type, the microbial growth must be eliminated. Perform the following procedure

Deodorize the evaporator core using Deodorizing Aerosol Kit.

Perform the following steps in order to deodorize the A/C system

  1. Ensure that the plenum which draws outside air into the HVAC module is clear of debris.
  2. Disable the A/C compressor clutch operation by disconnecting the clutch coil electrical connector.
  3. Dry the evaporator core by performing the following steps: Start the engine. Select the warmest temperature setting. Select the recirculation mode. Run the blower motor on high for 10 minutes.
  4. Locate an area in the air conditioning duct between the blower motor and the evaporator core downstream of the blower motor.
  5. Drill a 3.175 mm (0.125 in) hole where the hole will not interfere with or damage the following components: The blower motor The evaporator core Any other operating part the of system
  6. Wear safety goggles and latex gloves in order to perform the following actions: Select the maximum blower speed. Insert the deodorizer extension tube into the hole to the mark on the extension tube. Use short spray bursts and vary the direction of spray for a 2-3 minute period of time.
  7. Shut the engine OFF. Allow the vehicle to sit for 3-5 minutes.
  8. Seal the 3.175 mm (0.125 in) hole with body sealer or RTV gasket compound.
  9. Start the engine.
  10. Operate the blower motor on high for 15-20 minutes to dry.
  11. Reconnect the A/C compressor clutch coil electrical connector.
  12. Verify proper clutch operation.

Refrigerant Recovery and Recharging (Non HP2)

Tools Required

  1. J 43600 ACR 2000 Air Conditioning Service Center. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  2. J 45037 A/C Oil Injector. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

Recharging

CAUTIONAvoid breathing the A/C Refrigerant 134a (R-134a) and the lubricant vapor or the mist. Exposure may irritate the eyes, nose, and throat. Work in a well ventilated area. In order to remove R-134a from the A/C system, use service equipment that is certified to meet the requirements of SAE J 2210 (R-134a recycling equipment). If an accidental system discharge occurs, ventilate the work area before continuing service. Additional health and safety information may be obtained from the refrigerant and lubricant manufacturers.
CAUTIONFor personal protection, goggles and gloves should be worn and a clean cloth wrapped around fittings, valves, and connections when doing work that includes opening the refrigerant system. If R-134a comes in contact with any part of the body severe frostbite and personal injury can result. The exposed area should be flushed immediately with cold water and prompt medical help should be obtained.

Note. R-134a is the only approved refrigerant for use in this vehicle. The use of any other refrigerant may result in poor system performance or component failure.

Note. To avoid system damage use only R-134a dedicated tools when servicing the A/C system.

Note. Use only Polyalkylene Glycol Synthetic Refrigerant Oil (PAG) for internal circulation through the R-134a A/C system and only 525 viscosity mineral oil on fitting threads and O-rings. If lubricants other than those specified are used, compressor failure and/or fitting seizure may result.

Note. R-12 refrigerant and R-134a refrigerant must never be mixed, even in the smallest of amounts, as they are incompatible with each other. If the refrigerants are mixed, compressor failure is likely to occur. Refer to the manufacturer instructions included with the service equipment before servicing.

The J 43600 is a complete air conditioning service center for R-134a. See Special Tools . The ACR 2000 recovers, recycles, evacuates and recharges A/C refrigerant quickly, accurately and automatically. The unit has a display screen that contains the function controls and displays prompts that will lead the technician through the recover, recycle, evacuate and recharge operations. R-134a is recovered into and charged out of an internal storage vessel. The ACR 2000 automatically replenishes this vessel from an external source tank in order to maintain a constant 5.45-6.82 kg (12-15 lbs) of A/C refrigerant.

The ACR 2000 has a built in A/C refrigerant identifier that will test for contamination, prior to recovery and will notify the technician if there are foreign gases present in the A/C system. If foreign gases are present, the ACR 2000 will not recover the refrigerant from the A/C system.

The ACR 2000 also features automatic air purge, single pass recycling and an automatic oil drain.

Refer to the J 43600 ACR 2000 manual for operation and setup instruction. See Special Tools . Always recharge the A/C System with the proper amount of R-134a. Refer to Refrigerant System Capacities for the correct amount.

A/C Refrigerant System Oil Charge Replenishing

If oil was removed from the A/C system during the recovery process or due to component replacement, the oil must be replenished. Oil can be injected into a charged system using J 45037 . See Special Tools . For the proper quantities of oil to add to the A/C refrigerant system, refer to Refrigerant System Capacities .

Flushing

Tools Required

  1. J 43600 Air Conditioning Service Center. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  2. J 45268 Flush Adapter Kit. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  3. J 41447 Leak Detection Dye. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  4. J 42220 Universal 12V Leak Detection Lamp
IMPORTANTFlushing with the ACR 2000 is not intended to remove metal from the A/C system.

Flushing is intended to remove the following contaminants

  1. Contaminated PAG oil
  2. Desiccant, following a desiccant bag failure
  3. Overcharge of PAG oil
  4. Refrigerant contamination
  1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the TXV. Refer to «Thermal Expansion Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  3. Install J 45268 - 103. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  4. Remove the A/C compressor. Refer to «Air Conditioning Compressor Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  5. Install J 45268 - 5 to the discharge hose. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  6. Install J 45268 - 4 to the suction hose. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  7. Forward flow refrigerant flushing is recommended for contaminated refrigerant or PAG oil. Perform the following procedure: IMPORTANT: The filter inside J 45268 - 1 is serviceable. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Remove and discard the check valve from the filter. Service the filter with ACDelco P/N GF 470, before each flush. Connect J 45268 - 1 flush filter to the suction port of J 45268 - 4 flush adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Connect the blue hose from J 43600 to J 45268 - 1 flush filter adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Connect the red hose from J 43600 to J 45268 - 5 flush adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  8. Reverse flow refrigerant flush is recommended for desiccant bag failure. Replace the receiver dehydrator when the A/C flush is complete and perform the following procedure: IMPORTANT: The filter inside J 45268 - 1 is serviceable. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Remove and discard the check valve from the filter. Service the filter with ACDelco P/N GF 470, before each flush. Connect J 45268 - 1 flush filter to the discharge port of J 45268 - 5 flush adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Connect the blue hose from J 43600 to J 45268 - 1 flush filter adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Connect the red hose from J 43600 to the suction port of J 45268 - 4 flush adapter. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  9. Flush the A/C system. Follow the instructions supplied with J 43600 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) . Close the valve on the external refrigerant tank, before starting the flush process.
  10. Remove J 45268 - 4 from the suction hose. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  11. Remove J 45268 - 5 from the discharge hose. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  12. Remove J 45268 - 1 from J 43600 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  13. Drain the PAG oil from the A/C compressor. Rotate the compressor input shaft to assist in draining the PAG oil from the compressor.
  14. Add back the total system capacity of PAG oil to the A/C compressor. Refer to «Refrigerant System Capacities»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities) .
  15. Add one bottle of J 41447 directly to the A/C compressor. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  16. Install the A/C compressor. Refer to «Air Conditioning Compressor Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  17. Remove J 45268 - 103. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  18. Install new seal washers. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  19. Inspect the TXV for debris. Clean or replace as needed.
  20. Install the TXV. Refer to «Thermal Expansion Valve Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  21. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  22. Leak test the fittings using J 42220 .

Draining Procedure

  1. Before draining oil, position the compressor verdically (clutch facing upwards) and let it sit for 1 minute.
  2. Position the compressor horizontally, with the ports facing downward, rotate the clutch and shake the compressor in order to remove as much oil from the compressor as possible.
  3. Drain the oil from both the suction and discharge ports of the removed compressor into a clean, graduated container. Rotate the compressor shaft to assist in draining the compressor.
  4. Measure and record the amount of oil drained from the removed compressor. This measurement will be used during installation of the replacement compressor.
  5. Properly discard the used refrigerant oil.

Balancing Procedure

  1. Before installing the compressor, the refrigerant oil will have to be fully drained.
  2. Add back the same quantity of polyalkylene glycol (PAG) oil as drained from the removed compressor. Refer to the amount of refrigerant oil recorded during the compressor removal.

Tools Required

J 39400-A Halogen Leak Detector. See Special Tools .

Removal Procedure

  1. Recover the refrigerant from the system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  3. Remove the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-29l) for the 2.9L engine or «Drive Belt Replacement»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l) for the 3.7L engine.
  4. Disconnect the compressor electrical connectors.
  5. Remove the discharge hose bolt from the compressor.
  6. Remove the suction hose from the compressor.
  7. Remove the compressor hose assembly blocks from the compressor.
  8. Remove the compressor mounting bolts from the compressor (1).
  9. Remove the compressor.
  10. Drain and measure the compressor oil. Refer to «Air Conditioning Compressor Oil Balancing»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .

Installation Procedure

  1. Adjust the proper amount of oil to the replacement compressor. Refer to «Refrigerant System Capacities»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities) .
  2. Install the compressor.
  3. Install the compressor mounting bolts to the compressor (1). Tighten: Tighten the bolts to 50 N.m (37 lb ft).
  4. Install the compressor hose assembly blocks to the compressor.
  5. Install the suction hose to the compressor
  6. Install the discharge hose bolt to the compressor (1). Tighten: Tighten the bolts to 33 N.m (24 lb ft).
  7. Connect the compressor electrical connectors.
  8. Install the drive belt. Refer to «Drive Belt Replacement»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-29l) for the 2.9L engine or «Drive Belt Replacement»(/chevrolet/colorado/i-2004-2012/remont/mechanical/#engine-mechanical-37l) for the 3.7L engine.
  9. Install the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  10. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  11. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  1. Remove the compressor. Refer to «Air Conditioning Compressor Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  2. Remove the clutch plate retaining bolt (1).
  3. Remove the clutch plate assembly (2).
  4. Remove the clutch hub/bearing snap ring (3).
  5. Remove the clutch hub/bearing assembly (4).
  1. Install the clutch hub/bearing assembly (4).
  2. Install the clutch hub/bearing snap ring (3).
  3. Install the clutch plate assembly (2).
  4. Install the clutch plate retaining bolt (1). Tighten: Tighten the bolt to 18 N.m (13 lb ft).
  5. Install the compressor. Refer to «Air Conditioning Compressor Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  1. Remove the seal washer from the A/C refrigerant component.
  2. Inspect the seal washer for signs of damage to help determine the root cause of the failure.
  3. Inspect the A/C refrigerant components for damage or burrs. Repair if necessary.
  4. Discard the sealing washer.
  1. Inspect the new seal washer for any signs of cracks, cuts, or damage. Do not use a damaged seal washer.
  2. Remove the cap or tape from the A/C refrigerant components.
  3. Using a lint-free clean, dry cloth, clean the sealing surfaces of the A/C refrigerant components.
  4. Carefully install the new seal washer onto the A/C refrigerant component. The washer must completely bottom against the surface of the fitting.
  5. Assemble the remaining A/C refrigerant components. Refer to the appropriate repair procedure.
  1. Disassemble the A/C refrigerant components. Refer to the appropriate repair procedure For compression style fittings use a back up wrench on the fitting (2) and loosen the fitting nut (1). For banjo style fittings remove the bolt retaining the banjo type fitting.
  2. Remove the O-ring seal from the A/C refrigerant component.
  3. Inspect the O-ring seal for signs of damage to help determine the root cause of the failure.
  4. Inspect the A/C refrigerant components for damage or burrs. Repair if necessary.
  5. Cap or tape the A/C refrigerant components.
  6. Discard the O-ring seal.
  1. Inspect the new O-ring seal for any sign or cracks, cuts, or damage. Replace if necessary.
  2. Remove the cap or tape from the A/C refrigerant components.
  3. Using a lint-free clean, dry cloth, carefully clean the sealing surfaces of the A/C refrigerant components.
  4. Lightly coat the new O-ring seal with mineral base 525 viscosity refrigerant oil.
  5. Carefully slide the new O-ring seal onto the A/C refrigerant component.
  6. The O-ring seal must be fully seated.
  7. Assemble the A/C components. Refer to the appropriate repair procedure. For compression style fittings use a back up wrench on the fitting (2) and tighten the fitting nut (1) to specification. For banjo style fittings install the bolt retaining the banjo type fitting and tighten to specification.

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  3. Remove the discharge hose mounting bolt (8) from the A/C compressor.
  4. Remove the discharge hose (4) from the A/C compressor.
  5. Remove the discharge hose bolt from the condenser.
  6. Remove the discharge hose from the condenser.
  7. Remove the discharge hose from the vehicle.
  8. Discard all of the used sealing washers. Cap the system openings.
  1. Install the discharge hose to the condenser using new sealing washers. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  2. Install the discharge hose bolt to the condenser. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
  3. Install the discharge hose (4) to the A/C compressor using new sealing washers. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  4. Install the discharge hose mounting bolt (8) to the A/C compressor. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
  5. Install the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  6. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  7. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  3. Remove the suction hose mounting bolt (1) from the A/C compressor (7).
  4. Remove the suction hose (2) from the A/C compressor.
  5. Remove the nut (4) from the TXV stud.
  6. Remove the suction hose from the TXV.
  7. Remove the suction hose assembly (4) from the vehicle.
  8. Discard all of the used sealing washers. Cap the system openings.
  1. Install the suction hose (4) to the vehicle.
  2. Install new sealing washers. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  3. Install the suction hose to the TXV.
  4. Install the nut (4) to the TXV stud. Tighten: Tighten the nut to 16 N.m (12 lb ft).
  5. Install the suction hose (2) to the compressor using new sealing washers. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  6. Install the suction hose mounting bolt (1) to the A/C compressor (7). Tighten: Tighten the bolt to 16 N.m (12 lb ft).
  7. Install the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  8. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  9. Leak test the fittings of the component using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Recover the refrigerant from the system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the evaporator tube nut (1) from the TXV stud.
  3. Remove the evaporator tube (2) from the TXV.
  4. Remove the evaporator tube from the retaining clips (1) on the fender.
  5. Remove the grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
  6. Remove the evaporator tube retaining clip from the condenser.
  7. Remove the evaporator tube attaching bolt (1) at the receiver dehydrator.
  8. Remove the evaporator tube.
  9. Remove the O-ring seal and discard.
  1. Install the new O-ring seal. Refer to «O-Ring Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  2. Install the evaporator tube.
  3. Install the bolt (1) to the receiver dehydrator. Tighten: Tighten the nut to 28 N.m (21 lb ft).
  4. Install the evaporator tube retaining clip to the front of the condenser.
  5. Install the grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
  6. Install the evaporator tube to the retaining clips (1) on the fender.
  7. Install the evaporator tube (2) to the TXV.
  8. Install the evaporator tube nut (1) to the TXV stud.
  9. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  10. Leak test the fittings of the components using the J 39400 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

J 44551 Suction Screen Kit

  1. Remove the A/C suction hose from the A/C compressor. Refer to «Suction Hose Replacement (LLV, LLR)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  2. Using the J-44551-9 Universal Removal Tool, place the tip of the tool under the inside edge of the compression band of the suction screen and the cushioning fulcrum pad against the open end of the hose or manifold fitting.
  3. Pry upward on the band and move the tool around the diameter of the screen as necessary to remove the screen.
  1. Using a caliper that reads to 3 decimal places, measure the ID of the suction hose or manifold suction fitting. To determine the correct size screen for the application, refer to «Compressor Suction Screen and Tool Selection Specifications»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__compressor-suction-screen-and-tool-selection) .
  2. Select and install the correct mandrel (1) on the threaded portion of the installation tool bolt: The brass Universal Mandrel is for use on hose fittings with a smooth bore where the screen installs flush with the end of the fitting. The 11.96 mm (0.471 in) Mandrel is only for the 11.96 mm (0.471 in) screen in hose fittings with an internal hourglass shape where the screen installs at the recessed, reduced diameter point.
  3. Install the 11.96 mm (0.471 in) screen in the middle of the reduced diameter point of the fitting.
  4. Place the suction hose fitting or suction hose side of the manifold into the installation tool fixture J-44551-5 (3) so it is supported by the tools legs.
  5. Lubricate the A/C suction screen with the applicable refrigerant oil.
  6. Align the screen (2), basket first; into the suction hose bore then hand tighten the bolt until contact is made between the hose, screen and tool.
  7. Turn the bolt of the installation tool clockwise pressing the screen into the bore until the mandrel shoulder contacts the end of the hose fitting.
  8. Unscrew the bolt and remove the installation tool from the hose or manifold.
  9. Install the J-44551-1 Suction Screen Notification Label.
  10. Install the A/C hose to the A/C compressor. Refer to «Suction Hose Replacement (LLV, LLR)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  1. Remove the cover from the underhood convenience center (1).
  2. Remove the compressor relay (2).
  1. Install the compressor relay (2).
  2. Install the cover to the underhood convenience center (1).

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Recover refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .
  3. Remove the condenser hose bolt from the receiver dehydrator.
  4. Remove the condenser hose from the receiver dehydrator.
  5. Remove the evaporator tube bolt from the receiver dehydrator.
  6. Remove the evaporator tube from the receiver dehydrator.
  7. Install caps on the condenser hose and the evaporator tube assembly to prevent moisture entry and oil spillage.
  8. Remove the receiver dehydrator bracket bolts and the receiver dehydrator assembly.
  9. Loosen the receiver dehydrator clamp bolt and remove receiver dehydrator.
  1. If replacing the receiver dehydrator add the appropriate amount of PAG oil to the system. Refer to «Refrigerant System Capacities»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-system-capacities) for capacity information.
  2. Install the receiver dehydrator bottle into the clamp but do not tighten.
  3. Install new O-rings. Refer to «O-Ring Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  4. Install the receiver dehydrator bracket bolts.
  5. Tighten the receiver/dehydrator clamp bolt. Tighten: Tighten the bolt to 5 N.m (44 lb in).
  6. Remove the condenser hose to condenser cap and plug and install a new seal washer. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  7. Install the evaporator tube to the receiver dehydrator.
  8. Install the evaporator tube bolt to the receiver dehydrator. Tighten: Tighten the bolt to 20 N.m (15 lb ft).
  9. Install the condenser hose to the receiver dehydrator.
  10. Hand start the condenser hose bolt to the receiver dehydrator. Tighten: Tighten the bolt to 20 N.m (15 lb ft).
  11. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  12. Using the J 39400-A leak test the fittings of the component. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  13. Install the grille. Refer to «Grille Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#exterior-trim) .

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  2. Remove the nut from the TXV mounting stud.
  3. Remove the evaporator tube and the compressor suction hose from the TXV.
  4. Remove and discard the seal washers.
  5. Remove the TXV bolts.
  6. Remove the TXV.
  7. Remove and discard the seal washers.
  1. Install new seal washers to the evaporator core fittings. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  2. Install the TXV.
  3. Install the TXV bolts. Tighten: Tighten the bolts to 7 N.m (62 lb in).
  4. Install new sealing washers on the evaporator tube and the compressor suction hose fittings. Refer to «Sealing Washer Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  5. Install the evaporator tube and the compressor suction hose to the TXV.
  6. Install the TXV nut. Tighten: Tighten the nut to 20 N.m (15 lb ft).
  7. Evacuate and charge the refrigerant system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  8. Leak test the fittings using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Disconnect the A/C refrigerant pressure sensor electrical connector.
  2. Remove the A/C refrigerant pressure sensor from the evaporator inlet tube.
  1. Using a lint-free clean, dry cloth, carefully clean the sealing surfaces of the evaporator inlet tube fitting.
  2. Lightly coat the O-ring seal with mineral base 525 viscosity refrigerant oil.
  3. Install the A/C refrigerant pressure sensor to the evaporator inlet tube. Tighten: Tighten the sensor to 5 N.m (44 lb in).
  4. Connect the A/C refrigerant pressure sensor electrical connector.
  5. Leak test the fittings of the component using J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  1. Remove the radio. Refer to «Radio Replacement»(/chevrolet/colorado/i-2004-2012/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .
  2. Remove the mounting screw from the evaporator temperature control module.
  3. Disconnect the electrical connector from the control module.
  4. Cut the evaporator temperature sensor wire near the control module.
  5. Remove the evaporator core. Refer to «Air Conditioning Evaporator Core Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  6. Using needle nose pliers, carefully remove the evaporator temperature sensor from the evaporator core.
  1. Install the evaporator temperature sensor to the evaporator core. Place the sensor approximately 3.5 cm (1.4 in) from the side (a) and 5 cm (2 in) from the bottom (b) corner of the evaporator core.
  2. Align the evaporator temperature sensor wires with the opening in the upper HVAC module case.
  3. Install the evaporator core. Refer to «Air Conditioning Evaporator Core Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  4. Cut the evaporator temperature sensor from the replacement assembly.
  5. Connect the original sensor wire to the replacement assembly. Refer to «Splicing Copper Wire Using Splice Sleeves»(/chevrolet/colorado/i-2004-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-service-troubleshooting-diagnosis) .
  6. Connect the electrical connector to the evaporator temperature control module.
  7. Install the mounting screw to the control module. Tighten: Tighten the screw to 1.9 N.m (17 lb in).
  8. Install the radio. Refer to «Radio Replacement»(/chevrolet/colorado/i-2004-2012/remont/entertainment-systems/#cellular-system-entertainment-system-and-navigation-system) .

J 39400-A Halogen Leak Detector. See Special Tools .

  1. Remove the radiator. Refer to «Radiator Replacement»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
  2. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  3. Remove the receiver dryer.
  4. Remove the condenser inlet hose bolt.
  5. Remove the condenser inlet hose.
  6. Remove the condenser outlet hose bolt.
  7. Remove the condenser outlet hose.
  8. Remove the condenser from mounts on the radiator (1).
  9. Remove the condenser.
  1. Install the condenser to the radiator.
  2. If replacing the condenser, transfer the components from the old condenser as necessary.
  3. Install the condenser to the mounts on the radiator (1).
  4. Install the condenser retaining bolts to the radiator. Tighten: Tighten the bolts to 28 N.m (21 lb ft).
  5. Install the receiver dyer.
  6. Install the condenser inlet hose.
  7. Install the condenser inlet hose bolt. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  8. Install the condenser outlet hose.
  9. Install the condenser outlet hose bolt. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  10. Install the radiator. Refer to «Radiator Replacement»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
  11. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  12. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .

HVAC Module Assembly Replacement

Tools Required

  1. J 43181 Heater Line Quick Connect Release Tool. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  2. J 39400-A Halogen Leak Detector. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  1. Drain the engine coolant. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  2. Recover the refrigerant. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  3. Remove the instrument panel (I/P) carrier. Refer to «Instrument Panel Carrier Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  4. Release the heater hose clamps using J 43181 . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  5. Disconnect the heater hose quick connects (2) and (3) from the heater core.
  6. Remove the retaining nut from the TXV stud.
  7. Remove the evaporator tube and suction hose from the TXV.
  8. Remove the radio antenna from the HVAC module.
  9. Reposition the carpet.
  10. Remove rear floor duct. Refer to «Rear Floor Air Outlet Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  11. Remove the HVAC module retaining nuts from the cowl.
  12. Remove the HVAC module assembly.
  1. Install the HVAC module assembly.
  2. Install the HVAC module retaining nuts from the cowl.
  3. Tighten the HVAC module retaining nuts. Tighten: Tighten the nut to 4.5 N.m (40 lb in).
  4. If replacing the HVAC module assembly (8), transfer the components from the old HVAC module assembly as necessary.
  5. Install the HVAC module assembly (8).
  6. Install rear floor duct. Refer to «Rear Floor Air Outlet Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning) .
  7. Reposition the carpet.
  8. Install the radio antenna to the HVAC module.
  9. Connect the heater hose quick connects (2) and (3) to the heater core.
  10. Install the evaporator tube and suction hose to the TXV.
  11. Install the retaining nut to the TXV stud.
  12. Tighten the retaining nut. Tighten: Tighten the nut to 4.5 N.m (40 lb in).
  13. Install the I/P carrier. Refer to «Instrument Panel Carrier Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  14. Evacuate and recharge the A/C system. Refer to «Refrigerant Recovery and Recharging (Non HP2)»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__refrigerant-recovery-and-recharging-non-hp2) .
  15. Leak test the fittings of the components using the J 39400-A . See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  16. Refill the engine coolant. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  1. Remove the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove the screws to separate the HVAC module assembly halves.
  3. Remove the evaporator temperature sensor control module screw.
  4. Reposition the evaporator temperature sensor control module.
  5. Separate the HVAC module assembly (1, 4).
  6. Remove the evaporator temperature sensor from the evaporator.
  7. Remove the evaporator core (1) from the HVAC module assembly.
  1. Install the seal between the HVAC module assembly halves.
  2. Install the evaporator core (1) to the HVAC module assembly.
  3. Install the evaporator temperature sensor to the evaporator core.
  4. Assemble the HVAC module assembly.
  5. Install the screws to join the HVAC module assembly halves. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
  6. Install the evaporator temperature sensor control module screw. Tighten: Tighten the to 1.9 N.m (17 lb in).
  7. Install the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .

Heater Inlet Hose Replacement

Tools Required

  1. J 38185 Hose Clamp Pliers
  2. J 43181 Heater Line Quick Connect Release Tool. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  1. Drain the engine coolant. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  2. Using the J 43181 , release the inlet heater hose quick connect (1) from the heater core inlet. See «Special Tools»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__special-tools) .
  3. Position the inlet heater hose clamp (4) at the engine block using J 38185 .
  4. Remove the heater inlet hose (3) from the inlet hose fitting (6) at the engine block.
  5. Remove the heater inlet hose (3).
  1. Apply coolant to the end of the heater inlet hose (5).
  2. Install the heater inlet hose (3) to the inlet hose fitting (6) at the engine block.
  3. Position the inlet heater hose clamp (4) at the engine block using J 38185 .
  4. Install the heater inlet hose (3) to the heater core inlet.
  5. Press the quick connect (1) onto the heater core inlet until fully seated.
  6. Fill the engine cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .

J 38185 Hose Clamp Pliers

  1. Drain the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  2. Remove the transmission. Refer to «Transmission Replacement (RWD)»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) or «Transmission Replacement (4WD)»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) .
  3. Remove the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  4. Using the J 38185 disconnect the outlet hose from the heater core outlet tube.
  5. Remove the heater outlet hose from the heater core.
  6. Position the outlet heater hose clamp (6) at the water pump using J 38185 .
  7. Remove the heater outlet hose (7) from the outlet hose fitting.
  8. Remove the heater outlet hose.
  1. Install the outlet heater hose.
  2. Install the heater outlet hose (7) to the outlet hose fitting.
  3. Position the outlet heater hose clamp (6) at the outlet hose fitting using J 38185 .
  4. Install the heater outlet hose to the heater core.
  5. Position the outlet heater hose clamp at the heater core using J 38185 .
  6. Install the transmission. Refer to «Transmission Replacement (RWD)»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) or «Transmission Replacement (4WD)»(/chevrolet/colorado/i-2004-2012/remont/automatic-trans/#how-to-overhaul-the-automatic-transmission-4l60-e4l65-e4l70-e-removal-installation-service-troubleshooting-diagnosis) .
  7. Install the generator. Refer to «Generator Replacement»(/chevrolet/colorado/i-2004-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  8. Fill the cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .

J 38185 Hose Clamp Pliers

  1. Drain the engine cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  2. Using the J 38185 , reposition the heater hose outlet clamp from the heater pipe inlet.
  3. Remove the heater hose outlet from the heater pipe inlet.
  4. Remove the exhaust heat sheild. Refer to «Exhaust Manifold Heat Shield Replacement (LLV)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Manifold Heat Shield Replacement (LLR)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system) .
  5. Remove the heater inlet pipe bolt.
  6. Remove the heater inlet pipe.
  1. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the heater outlet hose fitting threads.
  2. Install the heater outlet hose fitting. Tighten: Tighten the heater outlet hose fitting to 45 N.m (33 lb ft).
  3. Install the heater hose outlet to the heater pipe inlet.
  4. Using the J 38185 , reposition the heater hose outlet clamp to the heater pipe inlet.
  5. Install the exhaust heat sheild. Refer to «Exhaust Manifold Heat Shield Replacement (LLV)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Manifold Heat Shield Replacement (LLR)»(/chevrolet/colorado/i-2004-2012/remont/exhaust/#engine-exhaust-system) .
  6. Fill the engine cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .

J 38185 Hose Clamp Pliers

  1. Drain the engine cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  2. Using the J 38185 , reposition the heater hose inlet clamp from the heater pipe outlet.
  3. Remove the heater hose inlet from the heater pipe outlet.
  4. Loosen the heater pipe outlet.
  5. Remove the heater pipe outlet.
  1. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent to the heater outlet hose fitting threads.
  2. Install the heater outlet hose fitting. Tighten: Tighten the heater outlet hose fitting to 45 N.m (33 lb ft).
  3. Install the heater hose inlet to the heater pipe outlet.
  4. Using the J 38185 , reposition the heater hose inlet clamp to the heater pipe outlet.
  5. Fill the engine cooling system. Refer to «Cooling System Draining and Filling (Static Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-static) or «Cooling System Draining and Filling (Vac N Fill)»(/chevrolet/colorado/i-2004-2012/remont/cooling-system-mechanical/#engine-cooling-system__cooling-system-draining-and-filling-vac) .
  1. Disconnect the blower motor resistor electrical connector (1).
  2. Remove the blower motor resistor mounting screws.
  3. Remove the blower motor resistor (2).
  1. Install the blower motor resistor (2).
  2. Install the blower motor resistor mounting screws. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
  3. Connect the blower motor resistor electrical connector (1).
  1. Remove the right hinge pillar trim panel. Refer to «Body Hinge Pillar Trim Panel Replacement - Right Side»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  2. Remove the blower motor mounting screws.
  3. Remove the blower motor cooling tube (2).
  4. Disconnect the blower motor electrical connector (4).
  5. Remove the blower motor (3).
  1. Install the blower motor (3).
  2. Connect the blower motor electrical connector (4).
  3. Install the blower motor cooling tube (2).
  4. Install the blower motor mounting screws. Tighten: Tighten the screws to 2 N.m (18 lb in).
  5. Install the right hinge pillar trim panel. Refer to «Body Hinge Pillar Trim Panel Replacement - Right Side»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#interior-trim-and-paneling) .
  1. Remove the instrument panel (I/P) assembly. Refer to «Instrument Panel Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  2. Remove the air distributor duct (1) from the instrument panel.
  1. Install the air distributor duct (1) to the instrument panel.
  2. Install the retaining screws to the air distributor duct. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
  3. Install the I/P assembly. Refer to «Instrument Panel Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  1. Using a flat-bladed plastic tool, carefully release the 4 tabs (1) retaining the air outlet assembly to the instrument panel (I/P).
  2. Remove the air outlet assembly from the I/P
  3. If replacing the vent assembly or the bezel, separate the bezel from the vent assembly by carefully releasing the 4 retaining tabs.
  1. If replacing the vent assembly or the bezel, install the bezel to the vent assembly by seating the 4 retaining tabs.
  2. Install the air outlet assembly to the I/P ensuring the retaining tabs are fully seated.
  1. Remove the instrument panel (I/P) accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  2. Remove the right air outlet assembly from the trim plate.
  3. Remove the left air outlet assembly from the trim plate.
  1. Install the left air outlet assembly to the trim plate.
  2. Install the right air outlet assembly to the trim plate.
  3. Install the accessory trim plate. Refer to «Instrument Panel Accessory Trim Plate Replacement»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  1. Using a flat-bladed plastic tool, carefully release the 4 tabs (1) retaining the air outlet assembly to the instrument panel (I/P).
  2. Remove the air outlet assembly from the I/P
  3. If replacing the vent assembly or the bezel, separate the bezel from the vent assembly by carefully releasing the 4 retaining tabs.
  1. If replacing the vent assembly or the bezel, install the bezel to the vent assembly by seating the 4 retaining tabs.
  2. Install the air outlet assembly to the I/P ensuring the retaining tabs are fully seated.
  1. Remove the floor console. Refer to «Console Replacement (Small W/ Manual Transmission)»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) or «Console Replacement (Large w/Manual or Auto Transmission)»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  2. Roll the carpeting back to expose the rear floor air ducts.
  3. Remove the rear floor ducts from the floor studs.
  4. Remove the rear floor duct.
  1. Install the rear floor air duct.
  2. Install the rear floor ducts from the floor studs.
  3. Position the carpeting back into place.
  4. Install the floor console. Refer to «Console Replacement (Small W/ Manual Transmission)»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) or «Console Replacement (Large w/Manual or Auto Transmission)»(/chevrolet/colorado/i-2004-2012/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
  1. Remove the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove screws in order to separate the HVAC module assembly.
  3. Remove the air temperature cam screw.
  4. Remove the air temperature cam.
  5. Remove the air temperature door linkage.
  6. Separate the HVAC module case halves.
  7. Remove the air temperature door (2).
  1. Install the air temperature door (2) to the HVAC module.
  2. Assemble the HVAC module case halves.
  3. Install the air temperature door linkage.
  4. Install the screws in order to assemble the HVAC module. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
  5. Install the air temperature cam.
  6. Install the screw to the air temperature cam. Tighten: Tighten the screw to 1.9 N.m (17 lb in).
  7. Install the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  1. Remove the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove all retaining screws from the HVAC module case halves (1 and 4).
  3. Separate the HVAC module case (1 and 4).
  4. Remove the screw from the mode cam.
  5. Remove the mode cam.
  6. Remove the defrost door linkage from the defrost door.
  7. Remove the defroster door (1) from the HVAC module assembly (2).
  1. Install the defroster door (1) from the HVAC module assembly (2).
  2. Install the defrost door linkage from the defrost door.
  3. Install the mode cam.
  4. Install the screw to mode cam. Tighten: Tighten the screw to 1.9 N.m (18 lb in).
  5. Assemble the HVAC module case (1 and 4).
  6. Install the screws to the HVAC module case. Tighten: Tighten the screws to 1.9 N.m (18 lb in).
  7. Install the HVAC module. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  1. Remove the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove the screws from the HVAC module assembly.
  3. Remove the screw from the mode cam.
  4. Remove the mode cam from the HVAC module assembly.
  5. Separate the HVAC module assembly halves (1 and 4).
  6. Remove the mode door linkage from the mode door.
  7. Remove the mode door (1) from the HVAC module assembly.
  1. Install the mode door to the HVAC module assembly.
  2. Install the mode door linkage to the mode door.
  3. Assemble the HVAC module assembly halves (1 and 4).
  4. Install the mode cam to the HVAC module assembly.
  5. Install the mode cam screw. Tighten: Tighten the screw to 1.9 N.m (18 lb in).
  6. Install the screws to the HVAC module assembly. Tighten: Tighten the screws to 1.9 N.m (18 lb in).
  7. Install the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  1. Remove the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove all retaining screws from the HVAC module case halves (1, 4).
  3. Separate the HVAC module case.
  4. Remove the screws retaining the recirculation actuator (2) from the HVAC module assembly.
  5. Remove the electrical connector (3) from the recirculation actuator (2).
  6. Remove recirculation actuator.
  7. Remove the recirculation door (2) from the recirculation assembly (1).
  1. Install the recirculation door (2) to the recirculation assembly (1).
  2. Install the recirculation actuator (2) to the case (1).
  3. Install the screws to the recirculation actuator. Tighten: Tighten the screws to 1.9 N.m (18 lb in).
  4. Connect the electrical connector (3).
  5. Assemble the HVAC module case halves (1, 4).
  6. Install the screws to assemble the HVAC module case halves. Tighten: Tighten the screws to 1.9 N.m (18 lb in).
  7. Install the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  1. Remove the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .
  2. Remove the heater core pipes clamp screw (3).
  3. Remove the heater core pipes clamp (2).
  4. Remove the heater core clamp screws.
  5. Remove the heater core clamp (2).
  6. Remove the heater core from the HVAC module.
  1. Install the heater core to the HVAC module.
  2. Install the heater core clamp (2).
  3. Install the heater core clamp screws. Tighten: Tighten the screws to 1.9 N.m (17 lb in).
  4. Install the heater core pipes clamp (2).
  5. Install the heater core pipes clamp screw (3). Tighten: Tighten the screw to 20 N.m (15 lb ft).
  6. Install the HVAC module assembly. Refer to «HVAC Module Assembly Replacement»(/chevrolet/colorado/i-2004-2012/remont/manual-hvac-system/#heating-ventilation-and-air-conditioning__hvac-module-assembly-replacement) .

Engine Coolant

Engine coolant is the key element of the heating system. The engine thermostat controls the normal engine operating coolant temperature. The thermostat also creates a restriction for the cooling system that promotes a positive coolant flow and helps prevent cavitation. Coolant enters the heater core through the inlet heater hose, in a pressurized state. The heater core is located inside the HVAC module. The ambient air drawn through the HVAC module absorbs the heat of the coolant flowing through the heater core. The HVAC module distributes heated air to the passenger compartment for consistent passenger comfort. Opening or closing the HVAC module temperature door controls the amount of heat delivered to the passenger compartment. The coolant exits the heater core through the return heater hose and is recirculated back through the engine cooling system.

A/C Cycle

Refrigerant is the key element in an air conditioning system. R-134a is presently the only EPA approved refrigerant for automotive use. R-134a is an very low temperature gas that can transfer the undesirable heat and moisture from the passenger compartment to the outside air.

The A/C compressor is belt driven and operates when the magnetic clutch is engaged. The compressor builds pressure on the vapor refrigerant. Compressing the refrigerant also adds heat to the refrigerant. The refrigerant is discharged from the compressor, through the discharge hose, and forced to flow to the condenser and then through the balance of the A/C system. The A/C system is mechanically protected with the use of a high pressure relief valve. If the high pressure switch were to fail or if the refrigerant system becomes restricted and refrigerant pressure continued to rise, the high pressure relief will pop open and release refrigerant from the system.

Compressed refrigerant enters the condenser in a high temperature, high pressure vapor state. As the refrigerant flows through the condenser, the heat of the refrigerant is transferred to the ambient air passing through the condenser. Cooling the refrigerant causes the refrigerant to condense and change from a vapor to a liquid state.

The condenser is located in front of the radiator for maximum heat transfer. The condenser is made of aluminum and aluminum cooling fins, which allows rapid heat transfer for the refrigerant. The semi-cooled liquid refrigerant exits the condenser and flows through the liquid line, to the thermal expansion valve.

The thermal expansion valve is located in the liquid line between the condenser and the evaporator. The thermal expansion valve is the dividing point for the high and the low pressure sides of the A/C system. As the refrigerant passes through the thermal expansion valve, the pressure of the refrigerant is lowered. Due to the pressure differential of the liquid refrigerant, the refrigerant will begin to vaporize at the thermal expansion valve. The thermal expansion valve also meters the amount of liquid refrigerant that can flow into the evaporator.

Refrigerant exiting the thermal expansion valve flows into the evaporator core in a low pressure, liquid state. Ambient air is drawn through the HVAC module and passes through the evaporator core. Warm and moist air will cause the liquid refrigerant boil inside of the evaporator core. The boiling refrigerant absorbs heat from the ambient air and draws moisture onto the evaporator. The refrigerant exits the evaporator back through the thermal expansion valve and into the suction line and back to the compressor, in a vapor state completing the A/C cycle of heat removal. At the compressor, the refrigerant is compressed again and the cycle of heat removal is repeated.

The conditioned air is distributed through the HVAC module for passenger comfort. The heat and moisture removed from the passenger compartment will also change form, or condense, and is discharged from the HVAC module as water under the vehicle.

Special Tools

Special Tools Illustration Tool Number/ Description J 38185 Hose Clamp Pliers J 39400 Electronic Halogen Leak Detector J 39400-A Halogen Leak Detector J 41447 R-134A A/C Tracer Dye - Box of 24 J 42220 Universal 12V Leak Detection Lamp J 43181 Heater Line Q.C. Release Tool J 43600 ACR 2000 Air Conditioning Service Center J 43872 Fluorescent Dye Cleaner J 45037 A/C Oil Injector J 45268 A/C Flushing Adapter Kit J 45297 A/C Dye Injector Kit J 45297-12 Replacement Dye Cartridges

Scheme 2

Scheme 2: Special Tools
Scheme 2: Special Tools

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10

See also:
• Diagnostic System Check - Vehicle
• Air Delivery Description and Operation
• Air Temperature Description and Operation
• Symptoms - HVAC Systems - Manual
• Moving Parts and Hot Surfaces Caution
• Air Temperature Malfunction
• Cooling System Description and Operation
• Drive Belt Falls Off and Excessive Wear Diagnosis
• Drive Belt Falls Off and Excessive Wear Diagnosis
• Vibration Analysis - Engine
• Instrument Panel Assembly Replacement
• Oil Leak Diagnosis
• Oil Leak Diagnosis
• Fluid Leak Diagnosis
• Power Steering Fluid Leaks
• Generator Replacement
• Fastener Notice
• Grille Replacement
• Radio Replacement
• Splicing Copper Wire Using Splice Sleeves
• Cooling System Draining and Filling (Static Fill)
• Cooling System Draining and Filling (Vac N Fill)
• Exhaust Manifold Heat Shield Replacement (LLV)
• Body Hinge Pillar Trim Panel Replacement - Right Side
• Special Tools
• Refrigerant Recovery and Recharging (Non HP2)
• Leak Testing
• Air Conditioning (A/C) Diagnostics - Pressure Zone A
• Air Conditioning (A/C) System Performance Test
• Receiver Dehydrator Replacement
• Flushing
• Refrigerant System Capacities
• Heating Performance Diagnostic
• Compressor Suction Screen and Tool Selection Specifications
• HVAC Module Assembly Replacement

More articles — HVAC