PIT5801B

Bulletin No.: PIT5801B
Published date: 12/8/2021
Preliminary Information
PIT5801B Diagnostic Tip / Vehicle Sits Unlevel / Leans / Sags /
Leveling Unavailable Message / Speed Limited Message / Service
Air Suspension Message / DTC C1190 C1191 C1192 C1193 C1187
C1188 C1189 C118A C118B C118C C118E C118F
Models
Brand:
Model:
Model Years:
VIN:
from
to
Engine:
Transmissions:
Cadillac
Escalade Models
2021 - 2022
All
All
All
All
Chevrolet
Suburban
2021 - 2022
All
All
All
All
Chevrolet
Tahoe
2021 - 2022
All
All
All
All
GMC
Yukon Models
2021 - 2022
All
All
All
All
Involved Region or Country North America
Additional Options (RPO)
Condition
Cause
F47 - Air Ride Suspension
Some customers may notice one or more of the following conditions related
with the air ride suspension.
- Vehicle suspension trim height is too high or too low at one or more corners.
- DIC Messages "Leveling Unavailable", "Service Air Suspension" and/or "Speed
Limited"
- DTC's: C1190, C1191, C1192, C1193, C1187, C1188, C1189, C118A, C118B, C118C,
C118E, C118F
The cause of these concerns could be one or more of the air lines not being fully
seated into an air spring or air manifold block assembly. An air line that is not fully
seated can cause the air spring to be either over in ated or under in ated.
It can be easy to understand and explain why an air line that is not fully seated can
cause an air spring to be under in ated, due to the air leaking out, but over in ated
air springs will require some additional details. The air springs use a unique air line
tting that contains a one way check valve. This one way check valve was needed for
manufacturing purposes to keep a small amount of air inside the air spring before it
is installed on the vehicle. Once the air spring is installed in the vehicle and the air
line is fully seated into the air spring tting, the one way check valve is no longer
needed and the air line holds the check valve open. If the air line is not fully seated
into the tting, it will not fully open the one way check valve. When this happens, air
can be pushed past the one way check valve into the air spring, but air can not be
released. This will cause the air spring to in ate but during a de ate it cannot
release the air from inside the air spring.
Because it is critical for the air lines to be fully seated into the air ttings, there are
white marks on each air line to indicate when the air line is fully seated. The air line
has to be inserted into the air tting until it bottoms out AND the white marks are
going into the top of the tting. Below is a picture of an air line, at one of the air
springs, which is NOT fully seated (1). This is indicated by the white markings not
actually going into the tting. The second photo below shows the air line after it was
fully seated (2). You can see the white marks are now down into the top of the air
line tting (2) and the air line is bottomed out in the tting.
NOTE: It is recommended to push the line into the tting as far as it will go. At least
part of the white marking MUST be into the top of the tting.
For additional examples see the third photo below. This is a picture of the air lines
at the air manifold block. In this example, there are several fully seated lines as
shown in call out 4. Each of these lines are fully seated as indicated by the white
markings being into the top of the air line tting. Call out 3 is an example of a line
that is not fully seated. In call out 3 you can see the white marking is not into the air
line tting as it should be.
Correction:
Note: The purpose of this PI is to focus on the air line connections at the air shocks and air manifold block. It is
understood that other issues with the air suspension system can cause over or under in ated air springs. In
addition to this PI, please follow all published SI diagnostics and safety procedures when working on the air
suspension system.
Typically, performing a very thorough inspection of each air line at the four shocks and manifold valve block will
prove to be the most fruitful way at discovering the root cause within the system. Make sure the white
marking on each air line is into the top of the tting and that the air line is bottomed out in the tting, as both
shown and described above. If an air line is not fully seated, then push the air line into the tting until it is fully
seated and the white marking is into the top of the tting. In most cases, there is no need to loosen the air line
tting to fully seat the air line.
Perform the following test to ensure the air lines are fully seated:
1. To test for an air spring that will not de ate due to the air line not being fully seated into the air spring,
perform the following test:
If this condition exists, suspect the side or corner that is sitting higher than the others. For example, if the vehicle
sits high on the left side, then suspect the left side air springs are not able to de ate.
A. Test using GDS2 (preferred):
- Ensure the battery is fully charged
- Close all Doors, Hood and Liftgate
- Ignition on and engine o
- Connect GDS2 and go into the Automatic Level Control Module > Data Display > Automatic Level Control System
Data and note the suspect corner's "Position O set from Trim" shown in millimeters (mm). Note: The units
button in GDS2 may have to be selected to change from cm to mm.
- Once the "Position O set from Trim" is noted for the suspect corner, then use GDS2 and go into Control
Functions > Short Term De ate > then select the suspect corner (LF, RF, LR, RR) and perform two short term
de ate commands.
- Once complete, use GDS2 and go back into Data Display > Automatic Level Control System Data and note the
suspect corner's "Position O set from Trim" again. Typically, the vehicle will lower 5 to 8 mm's. If the vehicle
does not lower after performing the Short Term De ates, then suspect the air line is not fully seated at the air
spring. In some cases, if the air spring is full of air and under high pressure, it can be very di cult to push the air
line into the air tting. This is because the one way check valve is being pushed closed by the high pressure air
inside the air spring. In these cases, try lifting the vehicle by the frame so the suspension is fully extended and/or
if necessary, while using extreme care, push the air line into the tting with a suitable tool. If the air line gets
kinked, pinched, or damaged, it will need to be replaced.
-B. Alternate test without using GDS2:
- Ignition turned o
- Vehicle frame supported
Important: The vehicle must be properly supported by the frame before performing test or injury may occur.
- Access the air compressor manifold block and locate the air line for the suspect air spring
- Slowly loosen the air line tting at the compressor manifold block, for the suspect air spring (it is not
necessary to completely remove). If air is released from the suspect air spring, then the air line is fully
seated/installed at the air spring. If air does NOT release from the suspect air spring, then inspect the air line for
not being fully seated/installed into the air spring tting and/or a blocked/kinked air line.
2. To test for an under in ation condition where the air line is not fully seated and leaking air, perform the
following test:
If this condition exists, then suspect the side or corner that is low. Example, if the vehicle sits very low on the left
side then suspect that the left side air spring lines may be leaking.
- Apply soapy water to the air lines and ttings at the air spring and air manifold block, while looking for any
leaks. If the air pressure is too low in the air spring, then perform the following steps to add air into the suspect
corner, while inspecting for any leaks.
- Ensure the battery is fully charged
- Close all Doors, Hood and Liftgate
- Ignition on and engine o
- Connect GDS2 and go into the Automatic Level Control Module > Control Functions > Short Term In ate > then
select the suspect corner (LF, RF, LR, RR) and perform short term in ate commands, as needed.
Note: If the vehicle was driven for a period of time with no air pressure in an air spring, it may have damaged the
air spring. Once the vehicle is repaired, a thorough inspection of the in ated air spring should be performed. If
any damage is found, or if it is uncertain that any damage occurred, then the air spring should be replaced.
Warranty Information
For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following
labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage
information.
Labor
Operation
Description
8020980
Automatic Level Control Module Replacement
8021000
Automatic Level Control Air Supply Reservoir Replacement
8044650
Rear Shock Absorber, Shock Absorber Component, Spring or Seat Air Line
8044651
Rear Shock Absorber, Shock Absorber Component, Spring or Seat Air Line Both Sides
Use Published
Time
Use Published
Time
Use Published
Time
Use Published
Time
8033620
Front Shock Absorber, Shock Absorber Component, Spring or Seat Air Line -
Use Published
Labor Time
8033630
Left Side
Front Shock Absorber, Shock Absorber Component, Spring or Seat Air Line Right Side
Time
Use Published
Time
Version History
Version
Modi ed
3
11/30/2020 - Created on.
04/19/2021 - Update to warranty sections
12/08/2021 - Update to the Correction, Warranty sections and Model Years.
© 2022 General Motors. All Rights Reserved.