99-01-37-009C

Bulletin No.:
Service Bulletin
Date:
99-01-37-009C
March, 2023
TECHNICAL
Subject:
Odor from A/C at Vehicle Start-Up (Remove Debris from Evaporator Case, Disinfect
Evaporator or Apply Cooling Coil Coating, and/or Enable Afterblow Function)
Models:
2000-2002 Saturn S-Series Vehicles with A/C (RPO C60)
Attention: Parts Manager and Technician
This bulletin is being revised to update the Customer Information. Please discard Corporate
Bulletin Number 99–01–37–009B (Section 01 — HVAC).
Condition
Some customers may comment on a musty odor from
A/C system, most noticeable at vehicle start-up.
Cause
An unpleasant (musty) odor from A/C outlets at vehicle
start-up may be the result of microbial growth on the
evaporator core. This bacteria feeds on the organic
matter and moisture that is present on the
evaporator core.
Correction
Remove any debris from evaporator case, clean
evaporator with disinfectant or apply cooling coil
coating, and/or enable afterblow function according to
the procedures in this bulletin.
Important: Before enabling afterblow function, the
following information must be explained to the
customer.
Customer Information
The current draw of the blower motor will lower the
state of charge of the vehicle’s battery, and may
negatively impact battery life depending on the driving
habits of the customer. The delayed blower motor
control function will not affect normal A/C or blower
motor operation. However, the body control module
(BCM) will activate the blower motor on high speed for
32 or 176 seconds, depending on the ambient
temperature, vehicle speed, and if the A/C compressor
clutch has been engaged during the same ignition
cycle. The BCM will wait approximately 50 minutes
after the ignition is turned off before activating the
blower motor. The blower run time reduces the amount
of condensate on the evaporator core that my
contribute to undesirable odors. The blower motor will
be turned on with no driver input if the conditions as
Copyright 2023 General Motors LLC. All Rights Reserved.
stated above are met. The air rush sound created by
the blower motor is noticeable from outside of the
vehicle.
Procedures
A/C EVAPORATOR DISINFECTING/COOLING COIL
COATING APPLICATION
Depending on part availability, use A/C system
disinfectant kit or cooling coil coating when
performing this procedure.
Before starting procedures, obtain the following
equipment and supplies:
• A/C System Disinfectant Kit, P/N 21030784 (P/N
10953503 for Canada), or Cooling Coil Coating, P/
N 12346390.
• Cleaning Spray Gun, Special Tool SA9216NE, or
equivalent.
Caution: WHEN USING DISINFECTANT KIT, P/N
21030784, ORDINARY SAFETY GLASSES ARE NOT
SUFFICIENT.
• For Disinfectant Kit, P/N 21030784 (P/N
10953503 for Canada), use safety goggles or face
shield.
• For Disinfectant Kit, P/N 21030784 (P/N
10953503 for Canada), use a National Institute of
Occupational Safety and Health (NIOSH)
approved acid gas/organic vapor respirator with
chlorine dioxide cartridges (3M® P/N 5103-small,
5203-medium, 5303-large), which are to be used
with a pre-filter (P/N 5010) and retainer (P/N 501),
or equivalents.
• When applying Cooling Coil Coating, P/N
12346390, use safety glasses.
• Rubber gloves
Page 2
March, 2023
• Pedestal fan
• Plug, P/N 21121827
1. Dry evaporator by:
• Adjusting temperature to full hot
• Adjusting mode to heater only
• Turning RECIRC On
• Making sure A/C button is Off
• Close all doors and windows
• Start engine and allow to reach operating
temperature
• Allow blower motor to operate on HI blower for
5 minutes, once engine reaches operating
temperature
Caution: MAKE SURE VEHICLE IS PROPERLY
SUPPORTED AND SQUARELY POSITIONED ON
HOIST. TO HELP AVOID PERSONAL INJURY,
PROVIDE ADDITIONAL SUPPORT TO OPPOSITE
END OF VEHICLE THAT COMPONENTS ARE
REMOVED FROM.
2. Raise vehicle on a hoist.
Bulletin No.: 99-01-37-009C
880462
5. To reduce the risk of debris from entering the
HVAC module, check for gaps between cowl panel
foam and windshield, at base of windshield. Repair
gaps by repositioning panels or by removing cowl
panels and installing additional foam to panel. Use
Kent Industries P/N 40115 Adhesive Back Shim
Stock, or equivalent, 5/16 x 3/8 inch foam.
6. Place a drain pan directly below the HVAC drain to
collect disinfectant or cooling coil coating and rinse
water runoff.
7. Open all doors and windows in the vehicle and
position pedestal fan so that it provides cross
ventilation through the vehicle during the cleaning/
coating procedure.
8. Cover interior of vehicle to protect it from spray.
9. Disconnect blower motor connector.
880679
3. Check the HVAC module drain for blockage. If
necessary, clear drain hole with a soft blunt tool
such as the eraser end of a pencil.
4. Lower vehicle from hoist.
859699
Bulletin No.: 99-01-37-009C
March, 2023
10. Remove blower motor mounting screws and
remove blower motor assembly.
Notice: Use care when removing debris from front of
evaporator so no damage is done to the fins.
11. Check the HVAC module for debris through the
blower motor opening. Remove any debris from
evaporator face.
12. Install blower motor and connect electrical
connector.
Tighten
Tighten the Blower Motor Mounting Screws to
1.7Y(15 in-lbs).
Page 3
Caution: THIS PROCEDURE SHOULD ONLY BE
PERFORMED ON A COLD CAR. IT HAS BEEN
DEMONSTRATED THAT IRRITATING VAPORS WILL
BE FORMED IN THE ENGINE COMPARTMENT IF
THE DISINFECTANT COMING OUT OF THE DRAIN
OUTLET CONTACTS HOT ENGINE COMPONENTS.
DISINFECTANT CAN CAUSE SUBSTANTIAL, BUT
TEMPORARY EYE INJURY. DO NOT GET
DISINFECTANT IN EYES OR ON CLOTHING. WASH
THOROUGHLY WITH SOAP AND WATER AFTER
HANDLING.
FIRST AID: IF DISINFECTANT GETS INTO EYES,
HOLD EYELIDS OPEN AND FLUSH WITH A
STEADY, GENTLE STREAM OF WATER FOR 15
MINUTES. OBTAIN MEDICAL ATTENTION IF
IRRITATION PERSISTS.
1. Allow vehicle to cool down before performing
disinfectant procedure.
2. Put on rubber gloves, safety goggles and NIOSH
approved acid gas/organic vapor respirator.
3. Pour the small bottle of the two part A/C System
Disinfectant Kit, P/N 21030784 (P/N 10953503 for
Canada), into the large bottle. Put the cap back on
the large bottle and invert bottle once or twice to
mix the contents.
4. Using cleaning gun, Special Tool SA9216NE (or
equivalent siphon-type parts cleaning spray gun
capable of delivering 2 ounces per minute of liquid
with shop air at 552-620 kPa [80-90 psi]), insert
siphon hose into container of disinfectant. Take
care to place the bottle in a secure upright position
to avoid spilling contents.
880601
13. Using a 15/32 in. drill bit, attach a drill stop or depth
gauge, or masking tape to allow for a 4 mm (5/32
in.) depth.
14. Locate the center of the triangle shaped portion of
the plenum which slopes upward and to the right,
next to the left-most blower motor fastener.
Notice: Running the drill bit in more than 4 mm (5/32
in.) can damage the evaporator.
15. Drill a 15/32 in. hole. Be careful not to let the drill
bit penetrate beyond a 4 mm (5/32 in.) depth.
Important: Depending on part availability, two different
products may be available for use on A/C evaporators.
Select the appropriate procedure to follow based on the
product you will be using:
• If using the Disinfectant Kit, P/N 21030784 (P/N
10953503 for Canada), continue to the
“Evaporator Disinfecting Using Disinfectant
Kit, P/N 21030784” procedure in this bulletin.
• If using the Cooling Coil Coating, P/N
12346390, continue to the “Applying Cooling
Coil Coating, P/N 12346390, to Evaporator”
procedure in this bulletin.
EVAPORATOR DISINFECTING USING
DISINFECTANT KIT
Perform this procedure only if you are using A/C
System Disinfectant Kit, P/N 21030784.
880615
5. Insert nozzle tip of spray gun through the drilled
hole and orient so spray pattern will be parallel to
the evaporator face.
Page 4
March, 2023
880608
6. With blower motor on HI and engine Off, spray the
entire contents of the disinfectant mix. Rotate the
nozzle tip up and down while spraying disinfectant
to allow for an even distribution and to ensure full
coverage of the evaporator.
7. Turn blower motor Off.
8. Allow evaporator core to soak for at least 5
minutes.
9. With blower motor on HI, thoroughly rinse the
evaporator core (using the above procedure) with 1
quart of clean water to remove any disinfectant
residue.
Bulletin No.: 99-01-37-009C
Important: Before enabling afterblow function, refer to
Customer Information in this bulletin and review
operation of afterblow function with customer.
13. If the afterblow function is to be enabled (based on
customer input), proceed to "BCM Afterblow
Function Enabling" in this bulletin.
APPLYING COOLING COIL COATING, P/N
12346390, TO EVAPORATOR
Perform this procedure only if you are using Cooling
Coil Coating, P/N 12346390.
Caution: COOLING COIL COATING CAN CAUSE
TEMPORARY EYE INJURY. DO NOT GET COOLING
COIL COATING IN EYES OR ON CLOTHING. WASH
THOROUGHLY WITH SOAP AND WATER AFTER
HANDLING.
FIRST AID: IF COOLING COIL COATING GETS INTO
EYES, HOLD EYELIDS OPEN AND FLUSH WITH A
STEADY, GENTLE STREAM OF WATER FOR 15
MINUTES. OBTAIN MEDICAL ATTENTION IF
IRRITATION PERSISTS.
1. Allow vehicle to cool down before performing
cooling coil coating procedure.
2. Put on rubber gloves and safety glasses.
3. Using cleaning gun, Special Tool SA9216NE (or
equivalent siphon-type parts cleaning spray gun
capable of delivering 2 ounces per minute of liquid
with shop air at 552-620 kPa [80-90 psi]), insert
siphon hose into container of cooling coil coating.
Take care to place the bottle in a secure upright
position to avoid spilling contents.
4. Regulate shop air to 276-414 kPa (40-60 psi).
880615
880618
10. Install hole plug, P/N 21121827.
11. Properly dispose of disinfectant and rinse water
runoff collected in drain pan into a sanitary drain.
12. Remove protective covering from interior of
vehicle.
5. Insert nozzle tip of spray gun through the drilled
hole and orient so spray pattern will be parallel to
the evaporator face.
6. Apply cooling coil coating using short bursts and
rotating the nozzle tip up and down. This will allow
for an even distribution and to ensure full coverage
of the evaporator.
Bulletin No.: 99-01-37-009C
March, 2023
7. Allow evaporator core to soak for 30 minutes.
8. Dry evaporator by:
• Adjusting temperature to full hot
• Turning RECIRC On
• Making sure A/C button is Off
• Open windows 1/2 in. and close doors
• Start engine and allow to reach operating
temperature
• Allow blower motor to operate on HI blower for
5 minutes once engine reaches operating
temperature
9. Install hole plug, P/N 21121827.
10. Properly dispose of cooling coil coating runoff
collected in drain pan into a sanitary drain.
11. Remove protective covering from interior of
vehicle.
Important: Before enabling afterblow function, refer to
Customer Information in this bulletin and review
operation of afterblow function with customer.
12. If the afterblow function is to be enabled (based on
customer input), proceed to "BCM Afterblow
Function Enabling" in this bulletin.
BCM AFTERBLOW FUNCTION ENABLE
Using a Tech 2, enable BCM Afterblow Function by
performing the following:
1. Navigate to BODY CONTROL MODULE menu.
2. Select SPECIAL FUNCTIONS menu.
3. Select PERSONALIZATION.
Page 5
4. Select HVAC AFTERBLOW and press ENTER to
enable afterblow function.
5. Select SAVE OPTIONS.
Parts Information
Part Number
Description
12346390
Coating – A/C Evap Organic Matl
Growth Prev
21030784
(P/N 10953503
for Canada)
A/C System Disinfectant Kit
21121827
Hole Plug
Claim Information
To receive credit for this repair during the warranty
coverage period, submit a claim through the Saturn
Dealer System as follows:
Case
Type
Description
Labor
Operation
Code
Labor
Time
VW
Reprogram Afterblow
Function
D3317
0.2 hr
VW
Disinfect A/C System
and Reprogram
Afterblow Function
Z4046
1.4 hrs
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
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