Leak Testing
- J 39400-A Halogen Leak Detector
- J 41447 Leak Detection Dye. See «Special Tools»(ref-200405-S14942364402005102000000) .
- J 42220 Leak Detection Lamp. See «Special Tools»(ref-200405-S14942364402005102000000) .
- J 43872 Fluorescent Dye Cleaner. See «Special Tools»(ref-200405-S14942364402005102000000) .
- J 46297 A/C Dye Injector Kit. See «Special Tools»(ref-200405-S14942364402005102000000) .
- J 46297-12 Replacement Dye Cartridges. See «Special Tools»(ref-200405-S14942364402005102000000) .
Refrigerant Leak Testing
| IMPORTANT | General 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.
The only time that adding additional fluorescent dye is required is after flushing the A/C system.
Air Conditioning (A/C) Diagnostics - Pressure Zone A
| Step | Action | Value | Yes | No |
|---|
| DEFINITION: The high and low side pressures may be normal or slightly less than normal. Air Delivery Concern Slight Refrigerant Under Charge Refrigerant Contamination |
| 1 | Were you sent here from the A/C System Performance Test? | | Go to Step 2 | Go to Air Conditioning (A/C) System Performance Test |
| 2 | Refer to the panel air outlet temperatures recorded during the A/C system performance test. Does the discharge air temperature between the right and left center panel outlets vary by more than 1-2°C (2-3°F)? | | Go to Step 7 | Go to Step 3 |
| 3 | Did the customer mention that the A/C system output temperatures are good at first, but then turn warm during extended drives? | | Go to Step 4 | Go to Step 5 |
| 4 | Increase engine speed to 2000 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 D | Go to Step 5 |
| 5 | Refer 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 in Cautions and Notices. 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 7 | Go to Step 6 |
| 6 | Refer 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 8 | Go to Too Hot in Vehicle in HVAC Systems - Manual or Too Hot in Vehicle in HVAC Systems - Automatic |
| 7 | The 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 . Is the repair complete? | | Go to Step 14 | |
| 8 | The A/C system may be contaminated. View the ACR 2000 information screen for detection of foreign gases in the A/C system. Do foreign gases exist? | | Go to Step 9 | Go to Step 10 |
| 9 | Evacuate the A/C system to a scavenging tank. Refer to Refrigerant Recovery and Recharging . Recharge the A/C system to specifications. Is the repair complete? | | Go to Step 14 | |
| 10 | The 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 . Operate the A/C system and inspect the panel outlet air temperatures. Refer to Air Conditioning (A/C) System Performance Test . Are the panel outlet temperatures within the specified ranges of the A/C Performance Test Table? | | Go to Step 15 | Go to Step 11 |
| 11 | The A/C system may contain too much refrigerant oil. Recover the refrigerant from the A/C system. Refer to Refrigerant Recovery and Recharging . Remove the accumulator. Refer to Accumulator Replacement . Drain and measure the refrigerant oil from the accumulator. Was more than the specified amount of refrigerant oil drained from the accumulator? | 148 ml (5 oz) | Go to Step 12 | Go to Step 13 |
| 12 | Reinstall the accumulator. Refer to Accumulator Replacement . Flush the A/C system. Refer to Flushing (Front Only System) or Flushing (Auxiliary System) . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Are the repairs complete? | | Go to Step 14 | |
| 13 | Add the specified amount of refrigerant oil to the accumulator. Refer to Refrigerant System Capacities . Install the accumulator. Refer to Accumulator Replacement . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Are the repairs complete? | | Go to Step 14 | |
| 14 | Record the low and high side pressures and the I/P outlet air temperature. Compare the outlet 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 I/P panel outlet temperatures within specifications? | | Go to Step 15 | Go to Air Conditioning (A/C) System Performance Test |
| 15 | Operate the system in order to verify the repair. Did you find and correct the condition? | | System OK | Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Air Conditioning (A/C) Diagnostics - Pressure Zone A
Air Conditioning (A/C) Diagnostics - Pressure Zone B
| Step | Action | Yes | No |
|---|
| DEFINITION: The low side pressures is higher than normal and the high pressure is lower than normal. Malfunctioning A/C Compressor Refrigerant Under Charge |
| 1 | Were you sent here from the A/C System Performance Test? | Go to Step 2 | Go to Air Conditioning (A/C) System Performance Test |
| 2 | After continued operation of the A/C system, do the low and high side pressures equalize or become static? | Go to Step 5 | Go to Step 3 |
| 3 | Refer 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 in Cautions and Notices. The low side pressure equal to or above the specified pressure range of the A/C Performance table. Refer to Air Conditioning (A/C) System Performance Test . The high side pressure is below 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 5 | Go to Step 4 |
| 4 | Refer 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 in Cautions and Notices. The low side pressure is above the specified pressure range of the A/C Performance table. Refer to Air Conditioning (A/C) System Performance Test . The high side pressure is below 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 5 | Go to Air Conditioning (A/C) System Performance Test |
| 5 | The A/C system has a low refrigerant charge. Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the procedure complete? | Go to Step 6 | |
| 6 | Record the low and high side pressures as well as the I/P outlet air temperature after repairs are performed. Compare the pressures and outlet 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? | Go to Step 13 | Go to Step 7 |
| 7 | The A/C compressor is malfunctioning. Remove the expansion device and inspect for contamination. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Are there metal flakes on the expansion device? | Go to Step 9 | Go to Step 8 |
| 8 | Inspect the expansion device for a brown, powdery residue indicating desiccant in the A/C system. Is there a brown, powdery residue present? | Go to Step 11 | Go to Step 12 |
| 9 | Remove the compressor hose from the compressor. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . Inspect for metal flake contamination at the line connections and the compressor ports. Is there metal flake contamination present? | Go to Step 10 | Go to Step 12 |
| 10 | Replace the A/C compressor. Refer to Compressor Replacement (LL8) or Compressor Replacement (LM4) . Replace the orifice tube. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the repair complete? | Go to Step 13 | |
| 11 | Flush the A/C system. Refer to Flushing (Front Only System) or Flushing (Auxiliary System) . Replace the orifice tube. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Replace the A/C compressor. Refer to Compressor Replacement (LL8) or Compressor Replacement (LM4) . Replace the accumulator. Refer to Accumulator Replacement . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the repair complete? | Go to Step 13 | |
| 12 | Replace the A/C compressor. Refer to Compressor Replacement (LL8) or Compressor Replacement (LM4) . Evacuate and recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the repair complete? | Go to Step 13 | |
| 13 | Operate the system in order to verify the repair Did you find and correct the condition? | System OK | Go to Symptoms - HVAC Systems - Manual in HVAC - Manual OR Go to Symptoms - HVAC Systems - Automatic in HVAC - Automatic |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Air Conditioning (A/C) Diagnostics - Pressure Zone B
Air Conditioning (A/C) Diagnostics - Pressure Zone C
| Step | Action | Yes | No |
|---|
| DEFINITION: The low and the high side pressures are both higher than normal. Restricted Condenser Air Flow Cooling Fan Malfunction Expansion Device Malfunction |
| 1 | Were you sent here from the A/C System Performance Test? | Go to Step 2 | Go to Air Conditioning (A/C) System Performance Test |
| 2 | With the engine idling, turn ON the A/C. Inspect for proper cooling fan operation. Refer to Cooling System Description and Operation in Engine Cooling. Are the cooling fans ON and operating properly? | Go to Step 3 | Go to Step 5 |
| 3 | Visually inspect for the following: Restricted air flow Damaged condenser cooling fins Inspect for missing or misaligned air baffles. Do the following conditions exist? | Go to Step 4 | Go to Step 6 |
| 4 | Repair the air flow restriction. Is the repair complete? | Go to Step 9 | |
| 5 | Repair the cooling fan operation fault. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information. Is the repair complete? | Go to Step 9 | |
| 6 | CAUTION: Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. Feel the liquid line on both sides of the expansion device.Is the temperature the same before and after the expansion device? | Go to Step 7 | Go to Step 8 |
| 7 | Replace the damaged/faulty orifice tube. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Is the repair complete? | Go to Step 9 | |
| 8 | Air is in the refrigerant system, or the system is overcharged. Refer to the view screen on the 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 . Is the repair complete? | Go to Step 9 | |
| 9 | Record the low and high side pressures and the instrument panel (I/P) outlet air temperature after repairs are performed. Compare the pressures and outlet 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? | Go to Step 10 | Go to Air Conditioning (A/C) System Performance Test |
| 10 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual OR Symptoms - HVAC Systems - Automatic in HVAC Systems - Automatic |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Air Conditioning (A/C) Diagnostics - Pressure Zone C
Air Conditioning (A/C) Diagnostics - Pressure Zone D
| Step | Action | Yes | No |
|---|
| 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 |
| 1 | Were you sent here from the A/C System Performance Test? | Go to Step 2 | Go to Air Conditioning (A/C) System Performance Test |
| 2 | CAUTION: Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. Feel the liquid line before the expansion device.Is the liquid line cold before the expansion device? | Go to Step 3 | Go to Step 8 |
| 3 | Feel 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 7 | Go to Step 4 |
| 4 | Feel 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 11 | Go to Step 5 |
| 5 | Feel 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. The accumulator The compressor suction hose Did you feel an abrupt temperature change along the surfaces of any of the listed components? | Go to Step 7 | Go to Step 6 |
| 6 | Feel 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 between the evaporator core and the accumulator The accumulator 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 14 | Go to Step 8 |
| 7 | Recover the refrigerant. Refer to Refrigerant Recovery and Recharging . Remove the restriction from the component, or replace the component which produced an abrupt temperature drop. Is the repair complete? | Go to Step 9 | |
| 8 | Recover the refrigerant and evacuate the system. Refer to Refrigerant Recovery and Recharging . 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 9 | Go to Step 10 |
| 9 | Recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Is the cooling performance improved? | Go to Step 21 | Go to Step 10 |
| 10 | Leak test the system. Refer to Leak Testing . Repair any leaks. Is the repair complete? | Go to Step 21 | |
| 11 | The expansion device is restricted. Replace the expansion device. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Are metal flakes present? | Go to Step 12 | Go to Step 13 |
| 12 | Remove the compressor hose assembly from the vehicle. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . 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 18 | Go to Step 20 |
| 13 | If the expansion device was restricted with a brown or black residue, perform the following procedure: Flush the A/C system. Refer to Flushing (Front Only System) or Flushing (Auxiliary System) . Replace the accumulator. Refer to Accumulator Replacement . Are the repairs complete? | Go to Step 21 | |
| 14 | Recover the refrigerant. Refer to Refrigerant Recovery and Recharging . Disconnect the compressor hose from the compressor. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . Inspect for the presence of debris in the compressor suction port. Is debris present in the compressor suction port? | Go to Step 15 | Go to Step 19 |
| 15 | Remove the debris from the suction port. Inspect the expansion device for damage or debris. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . Did you find evidence of damage or debris? | Go to Step 17 | Go to Step 16 |
| 16 | If the expansion device does not show any signs of damage or debris, perform the following procedure: Remove the compressor hose assembly from the vehicle. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . 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 18 | Go to Step 19 |
| 17 | Replace the expansion device. Refer to Expansion (Orifice) Tube Replacement (Front Only System) or Expansion (Orifice) Tube Replacement (Auxiliary System) . If the expansion device was restricted, observe the type of debris present. Are metal flakes present? | Go to Step 12 | Go to Step 13 |
| 18 | If a large amount of debris was collected in the shop towel from the compressor hose assembly, perform the following procedure: Replace the accumulator. Refer to Accumulator Replacement . Is the repair complete? | Go to Step 19 | |
| 19 | Install the compressor hose assembly. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . Are the repairs complete? | Go to Step 21 | |
| 20 | Install the compressor hose assembly. Refer to Compressor Hose Assembly Replacement (LL8) or Compressor Hose Assembly Replacement (LM4) . Recharge the A/C system. Refer to Refrigerant Recovery and Recharging . Are the repairs complete? | Go to Step 21 | |
| 21 | Record the low and the high side pressures and the panel outlet air temperature after you perform the repairs. Compare the pressures and the panel outlet 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 22 | Go to Air Conditioning (A/C) System Performance Test |
| 22 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Symptoms - HVAC Systems - Manual in HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic in HVAC Systems - Automatic |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Air Conditioning (A/C) Diagnostics - Pressure Zone D
Heating Performance Diagnostic (Front System Only)
| Step | Action | Yes | No |
|---|
| DEFINITION: Heating system performance. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic |
| 2 | Start the engine. Allow the engine to idle. Does the engine reach a normal operating temperature? | Go to Step 3 | Go to Step 9 |
| 3 | CAUTION: Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. 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 7 | Go to Step 4 |
| 4 | Install a thermometer into the center IP 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 IP PANEL air outlet The heater core outlet hose Compare the recorded temperatures. Are the two temperature readings about equal? | Go to Step 5 | Go to Step 6 |
| 5 | Inspect 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 | |
| 6 | Inspect the temperature door operation. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information. Perform any necessary repairs. Are the repairs complete? | Go to Step 10 | |
| 7 | Turn 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 8 | Go to Step 10 |
| 8 | Replace the heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 10 | |
| 9 | Repair the low engine temperature concern. Refer to Engine Fails To Reach Normal Operating Temperature in Engine Cooling. Is the repair complete? | Go to Step 10 | |
| 10 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Heating Performance Diagnostic (Front System Only)
Heating Performance Diagnostic (Auxiliary System)
| Step | Action | Yes | No |
|---|
| DEFINITION: Heating system performance of the auxiliary heater. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic |
| 2 | Start the engine. Allow the engine to idle. Does the engine reach a normal operating temperature? | Go to Step 3 | Go to Step 14 |
| 3 | CAUTION: Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. Allow the engine to idle. Select the maximum auxiliary temperature setting. Select the minimum auxiliary blower speed. Feel the temperature of the inlet and outlet heater hoses to the auxiliary hot water bypass valve. Does the inlet heater hose feel warmer than the outlet heater hose? | Go to Step 4 | Go to Step 6 |
| 4 | Disconnect the vacuum hose from the coolant bypass valve. Is vacuum being applied to the valve? | Go to Step 13 | Go to Step 5 |
| 5 | Remove the coolant bypass valve. Refer to Coolant Bypass Valve Replacement . Inspect the coolant bypass valve for the following conditions: Binding Restrictions Damage Are any of these conditions present? | | Go to Step 16 |
| 6 | Allow the engine to idle. Select the minimum auxiliary blower speed. Select the warmest auxiliary temperature setting. Feel the temperature of the inlet and outlet heater hoses to the auxiliary heater core. Does the inlet heater hose feel warmer than the outlet heater hose? | Go to Step 10 | Go to Step 7 |
| 7 | Install a thermometer into an auxiliary air outlet. Secure a thermometer on the outlet heater hose of the auxiliary heater core. Select the maximum auxiliary blower speed. Select the warmest auxiliary temperature setting. Record the temperature at the following locations: The auxiliary air outlet The auxiliary heater core outlet hose Compare the recorded temperatures. Are the two temperature readings about equal? | Go to Step 8 | Go to Step 9 |
| 8 | Inspect the following areas of the vehicle for cold air leaks: The auxiliary HVAC module case The auxiliary air ducts Perform any necessary repairs. Is the repair complete? | Go to Step 16 | |
| 9 | Inspect the auxiliary HVAC module for correct temperature door operation. Refer to Diagnostic System Check - Vehicle in Vehicle DTC Information. Does the temperature door operate correctly? | Go to Step 16 | Go to Step 15 |
| 10 | Turn OFF the engine. Backflush the auxiliary heater core. Start the engine and allow the engine to idle. Select the minimum auxiliary blower speed. Select the warmest auxiliary temperature setting. Feel the temperature of the inlet and outlet heater hoses at the auxiliary heater core. Does the inlet heater hose feel warmer than the outlet heater hose? | Go to Step 11 | Go to Step 16 |
| 11 | Replace the auxiliary heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 16 | |
| 12 | Replace the coolant bypass valve. Refer to Coolant Bypass Valve Replacement . Is the repair complete? | Go to Step 16 | |
| 13 | Repair the vacuum condition. Refer to Vacuum Control System Diagnostic in HVAC Systems - Manual or Vacuum Control System Diagnostic in HVAC Systems - Automatic. Is the repair complete? | Go to Step 16 | |
| 14 | Repair the low engine temperature concern. Refer to Engine Fails To Reach Normal Operating Temperature in Engine Cooling. Is the repair complete? | Go to Step 16 | |
| 15 | Repair the temperature door operation. Is the repair complete? | Go to Step 16 | |
| 16 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
| CAUTION |
|---|
| Refer to Moving Parts and Hot Surfaces Caution in Cautions and Notices. |
Heating Performance Diagnostic (Auxiliary System)
Noise Diagnosis - Auxiliary Blower Motor
| Step | Action | Yes | No |
|---|
| DEFINITION: Noise originating from the auxiliary blower motor. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual in HVAC Systems Manual or Diagnostic System Check - Vehicle in Vehicle DTC Information |
| 2 | Sit inside the vehicle. Close the vehicle doors and windows. Turn ON the ignition, with the engine OFF. Cycle the auxiliary blower motor through all of the speeds and modes in order to determine where and when the noise occurs. Is a noise evident during auxiliary blower operation? | Go to Step 3 | Go to Step 10 |
| 3 | Does the noise vary with the auxiliary blower speed? | Go to Step 4 | Go to Step 5 |
| 4 | Inspect for excessive vibration at each auxiliary blower motor speed by feeling the auxiliary blower case. Is excess vibration present? | Go to Step 5 | Go to Step 10 |
| 5 | Remove the auxiliary blower motor. Refer to Blower Motor Replacement - Auxiliary (Rear Auxiliary) or Blower Motor Replacement - Auxiliary (Front Auxiliary) . Inspect the auxiliary blower motor for deposits of foreign material. Did you find foreign material on the auxiliary blower motor? | Go to Step 7 | Go to Step 6 |
| 6 | Inspect the auxiliary 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 8 | Go to Step 9 |
| 7 | Remove the foreign material. Is the action complete? | Go to Step 10 | |
| 8 | Replace the auxiliary blower motor. Refer to Blower Motor Replacement - Auxiliary (Rear Auxiliary) or Blower Motor Replacement - Auxiliary (Front Auxiliary) . Is the action complete? | Go to Step 10 | |
| 9 | Install the auxiliary blower motor. Refer to Blower Motor Replacement - Auxiliary (Rear Auxiliary) or Blower Motor Replacement - Auxiliary (Front Auxiliary) . Is the action complete? | Go to Step 10 | |
| 10 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Noise Diagnosis - Auxiliary Blower Motor
Noise Diagnosis - Blower Motor
| Step | Action | Yes | No |
|---|
| DEFINITION: Noise originating from the blower motor. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual or to Symptoms - HVAC Systems - Automatic |
| 2 | Sit inside the vehicle. Close the vehicle doors and windows. Turn ON the ignition switch, with the engine OFF. Cycle through all the blower motor speeds and modes in order to determine where noise occurs. Is the noise evident during blower operations? | Go to Step 3 | Go to Step 10 |
| 3 | Does the noise vary with the blower speed? | Go to Step 4 | Go to Step 10 |
| 4 | Inspect for excess vibration at each blower motor speed by feeling the blower case. Is excess vibration present? | Go to Step 5 | Go to Step 10 |
| 5 | Remove the blower motor. Refer to Blower Motor Replacement . Inspect the blower motor for deposits of foreign material. Did you find any foreign material on the blower motor? | Go to Step 7 | Go to Step 6 |
| 6 | Inspect 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 8 | Go to Step 9 |
| 7 | Remove the foreign material. Is the action complete? | Go to Step 10 | |
| 8 | Replace the blower motor. Refer to Blower Motor Replacement . Is the action complete? | Go to Step 10 | |
| 9 | Install the blower motor. Refer to Blower Motor Replacement . Is the action complete? | Go to Step 10 | |
| 10 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Noise Diagnosis - Blower Motor
Noise Diagnosis - Air Conditioning (A/C) System
| Step | Action | Yes | No |
|---|
| DEFINITION: Noise originating from the A/C compressor, drive belt or the A/C lines. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual in HVAC Systems Manual or Symptoms - HVAC Systems - Automatic in HVAC Systems Automatic |
| 2 | A/C system noises can be generally categorized into three areas: Screeching, squealing or chirping noises Moaning noises Vibration/Rattle noises Start the engine. Ensure that the A/C is ON. Do you hear a screeching, squealing noise when you engage the A/C? | Go to Step 3 | Go to Step 9 |
| 3 | With the engine OFF, inspect the drive belt for excessive wear. Refer to Drive Belt Excessive Wear Diagnosis in Engine Mechanical. Is the drive belt excessively worn? | Go to Step 18 | Go to Step 4 |
| 4 | Inspect the drive belt tension. Refer to Drive Belt Tensioner Diagnosis in Engine Mechanical. Is the drive belt tension correct? | Go to Step 5 | Go to Step 19 |
| 5 | Inspect the drive belt for excessive oil coverage. Is the drive belt covered with oil? | Go to Step 17 | Go to Step 6 |
| 6 | Start 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 23 | Go to Step 7 |
| 7 | Is the A/C compressor clutch slipping? | Go to Step 23 | Go to Step 8 |
| 8 | Using a stethoscope, listen to the A/C compressor for any abnormal noises. Is the compressor causing an abnormal noise? | Go to Step 15 | Go to Step 10 |
| 9 | Does a moaning noise exist when the A/C clutch is engaged? | Go to Step 10 | Go to Step 12 |
| 10 | Listen 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 20 | Go to Step 11 |
| 11 | Start 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 22 | Go to Step 13 |
| 12 | Does a vibration or rattle noise exist when the A/C clutch is engaged? | Go to Step 13 | Go to Step 14 |
| 13 | Does the noise stop when the A/C clutch is disengaged? | Go to Step 15 | Go to Step 24 |
| 14 | Idle the engine in PARK with the A/C compressor clutch engaged. Using a stethoscope, move around the entire A/C system listening for any abnormal noises caused by a component. Do any of the A/C components cause an abnormal noise? | Go to Step 21 | Go to Step 24 |
| 15 | Verify that the A/C system is properly charged. Refer to Refrigerant System Capacities . Is the A/C system properly charged? | Go to Step 24 | Go to Step 16 |
| 16 | Recharge the A/C system to specification. Refer to Refrigerant Recovery and Recharging . Is the abnormal compressor noise still present? | Go to Step 23 | Go to Step 25 |
| 17 | Repair the oil leak. Refer to the appropriate repair procedure in Engine Mechanical. Is the repair complete? | Go to Step 25 | |
| 18 | Replace the drive belt. Refer to Drive Belt Replacement in Engine Mechanical. Is the replacement complete? | Go to Step 25 | |
| 19 | Replace the drive belt tensioner. Refer to Drive Belt Tensioner Replacement in Engine Mechanical. Is the replacement complete? | Go to Step 25 | |
| 20 | Repair or replace the A/C compressor mounting component. Is the repair complete? | Go to Step 25 | |
| 21 | Repair or replace the component which is causing the moaning concern as needed. Is the repair complete? | Go to Step 25 | |
| 22 | Correctly route or insulate the A/C component. Is the repair complete? | Go to Step 25 | |
| 23 | Replace the A/C compressor. Refer to Compressor Replacement (LL8) or Compressor Replacement (LM4) . Is the replacement complete? | Go to Step 25 | |
| 24 | The concern may be caused by an engine related component. Refer to Vibration Analysis - Engine in Vibration Diagnosis and Correction. Did you find and correct the condition? | Go to Step 25 | |
| 25 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Noise Diagnosis - Air Conditioning (A/C) System
Noise Diagnosis - HVAC Module
| Step | Action | Yes | No |
|---|
| DEFINITION: Noise originating from the HVAC module. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual or Symptoms - HVAC Systems - Automatic |
| 2 | Start the engine. Cycle through all of the following: Blower motor speeds HVAC Modes Temperature control settings Attempt to define 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 6 | Go to Step 3 |
| 3 | Is a tick/click, chirping, groaning or scraping noise present, but decreases as blower motor speed is decreased? | Go to Step 6 | Go to Step 4 |
| 4 | Is an air rush/whistle noise evident in all modes but not all temperature settings? | Go to Step 6 | Go to Step 5 |
| 5 | Is an air rush/whistle noise evident only in defrost or floor mode? | Go to Step 6 | Go to Step 6 |
| 6 | Remove the I/P carrier. Refer to Instrument Panel (I/P) Carrier Replacement in Instrument Panel, Gages and Console. Is the action complete? | Go to Step 7 | |
| 7 | Inspect the air flow doors for proper operation. Inspect the ducts for obstructions or foreign materials. Were any of these conditions found? | Go to Step 12 | Go to Step 8 |
| 8 | Inspect the mode and temperature doors and seals for warping or cracking. Are the doors in normal condition? | Go to Step 10 | Go to Step 9 |
| 9 | Replace the appropriate door and/or seals. Is the repair complete? | Go to Step 11 | |
| 10 | Remove any obstructions or foreign material found. Is the action complete? | Go to Step 11 | |
| 11 | Install the I/P carrier. Refer to Instrument Panel (I/P) Carrier Replacement in Instrument Panel, Gages and Console. Is the action complete? | Go to Step 12 | |
| 12 | Operate the system to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
Noise Diagnosis - HVAC Module
Odor Diagnosis
| Step | Action | Yes | No |
|---|
| DEFINITION: Odor originating or noticed through the HVAC system. |
| 1 | Were you sent here from Symptoms or another diagnostic table? | Go to Step 2 | Go to Symptoms - HVAC Systems - Manual or 49126 |
| 2 | Sit 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 3 | Go to Step 8 |
| 3 | Inspect the HVAC filter and the air inlet grille for debris. Is debris present? | Go to Step 4 | Go to Step 5 |
| 4 | Remove any debris. Is the action complete? | Go to Step 15 | |
| 5 | Inspect for wet carpeting. Is the carpet wet? | Go to Step 6 | Go to Step 14 |
| 6 | Inspect 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 7 | Go to Step 14 |
| 7 | Repair the leak as necessary. Is the repair complete? | Go to Step 15 | |
| 8 | Does the odor have a coolant smell? | Go to Step 9 | Go to Step 12 |
| 9 | Inspect the cooling system for leaks. Refer to Loss of Coolant in Engine Cooling. Is a leak present? | Go to Step 10 | Go to Step 12 |
| 10 | Inspect for coolant leaking inside the vehicle or for a film build-up on the windshield. Is the condition present? | Go to Step 11 | Go to Step 15 |
| 11 | Replace the heater core. Refer to Heater Core Replacement . Is the repair complete? | Go to Step 15 | |
| 12 | Does the odor have an oily smell? | Go to Step 13 | Go to Step 15 |
| 13 | Inspect the engine compartment for any leaks. Refer to the following procedures: Oil Leak Diagnosis in Engine Mechanical - 4.2L Fluid Leak Diagnosis in Automatic Transmission - 4L 60-E Power Steering Fluid Leaks in Power Steering System Repair any oil leaks. Is the repair complete? | Go to Step 15 | |
| 14 | A 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 | |
| 15 | Operate the system in order to verify the repair. Did you find and correct the condition? | System OK | Go to Step 2 |
