Service Bulletin – Product

Subject: Transmission Low Air Pressure and/or Clutch Temperature Display Messages
– Endurant Transmissions
Document Number: TAIB-0876
Updated: May 11, 2021

Date: September 17, 2018

Issue Description:
Customers may experience a low transmission air pressure and/or clutch temperature
message during low speed maneuvering or stop and go traffic situations.
• Low transmission air pressure message: This issue may be induced by a
vehicle air system not functioning properly resulting in the inability to achieve or
maintain operating air pressure. Low air pressure may be induced by excessive
use or cycling of the service brake, exhausting the vehicle air supply.
• Clutch temperature message: This issue may be induced by “two footing” the
service brake and accelerator pedal simultaneously causing the clutch not to
fully close, inducing a clutch slip and increasing clutch temperature.
Fault codes that may set during these events:
• Transmission Air Supply Pressure: FC215 SPN 37 FMI 18
• Clutch Temperature: FC815 SPN 5939 FMI 15 and/or 16
Containment/Corrective Action:
Driver recommendations:
• Ensure the vehicle air system is operating per OEM requirements.
• Allow the vehicle air system to reach normal operating range, 99 (106 at the Air
Brake Tanks for Navistar) to 130 PSI (6.8 to 9.0 Bar), prior to selecting a gear
from neutral.
• Avoid “two footing” the service brake and accelerator pedal.
• Avoid using the accelerator pedal to hold the vehicle on a hill - depress and
hold the service brake until movement is required.
• During operation on a grade, rely on Hill Start Aid (HSA) when transitioning
from the service brake pedal to the accelerator pedal.
• During low speed maneuvering, select the lowest available start gear (1st or R1)
and rely on Urge to Move and Creep Mode to assist in moving the vehicle at
engine idle without having to apply the accelerator pedal.
Note: For additional information on how to operate the transmission refer to Driver
Instructions TRDR0950 and GET 2 KNOW videos .

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Service Bulletin – Product
Recommendations when messages are displayed:
•

Low transmission air message - allow the vehicle air system to reach normal
operating range (100 PSI or above / 106 at the Air Brake Tanks for Navistar)
and then continue operation. For optimal performance, the transmission
requires 99 to 130 PSI (6.8 to 9.0 Bar).
Note: Transmission software version 5516024 includes enhancements that
prevent Fault Code 215 from setting while transmission is in Neutral mode.
o Non-Navistar Chassis: With software version 5516024 and above, if
the driver attempts to select a non-neutral mode before transmission air
pressure reaches 80 psi, the transmission will prevent gear engagement
and Fault Code 215 will set Active.
o Navistar Chassis: At initial key on with software version 5516024 and
above, if a driver attempts to select a non-neutral mode before
transmission air pressure reaches 90 psi, and the air brake tanks reach
106 psi, the transmission will prevent gear engagement. The 106 psi
minimum on a Navistar chassis matches the tractor protection valve
(OEM Requirement). If chassis air pressure falls below 106 psi (Key on
normal operation) the transmission will continue to shift until a minimum
of 75 psi is reached (see Item A / Degraded Performance).

Note: Transmission and Air Brake Tanks can be monitored in SR4 / Data Monitor:

•

Clutch temperature message - safely and immediately discontinue the
operation that is being performed which is causing the clutch to overheat.
Depress and hold the service brake or set vehicle parking brake and idle the
engine until the message is no longer indicated and then continue normal
operation. Ensure the engine is allowed to idle, shutting off the engine prolongs
the condition.
Note: Transmission software version 5516024 includes enhancements that
allow the transmission to continue operation when Fault Code 815 sets.
Fallback mode of the Fault Code will still disable some transmission
functionality such as launching in a higher start gear and Urge to Move. The
driver will continue to be notified of a Clutch Abuse event via a dash message
and auditable tone. A software update to 5516024 for Fault Code 815 is
considered a non-warrantable issue.

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Service Bulletin – Product
NOTICE: In most cases the transmission will recover from the induced events outlined
above and towing of the vehicle is not required. In extreme cases depending on truck
operation, the air system requirement for air consumption may be higher than the
standard compressor (18.7 CFM) can produce. In those cases, a higher CFM (37.4)
compressor is available for aftermarket purchase (customer pay) or as an option in the
OEM Databook. See your Navistar representative for details.
Note: If the transmission low air and/or clutch temperature condition no longer exists
some OEM displays may require the driver to manually clear the message with older
cluster software versions. Refer to OEM guidelines regarding the display message
reset procedure.
Navistar is offering a dash cluster software update with 6024 transmission SW update
that has changed the warning displays. Reference Navistar iKNow article
(IK0800550).
•

Transmission Air Supply Low – Least Severe:
o Requirements to set dash response: Engine Running, Trans Current
Gear Neutral, Shift device Neutral, Vehicle Not Moving, and
Transmission Air Pressure < 90 psi or Brake Tank Pressure < 106 psi.
o Dash response was: “Transmission Air Pressure Low Warning” with
driver acknowledgment now “System Air Pressure Low” and does not
require the driver to manually clear the message

•

Transmission Air Supply Low – Moderately Severe Level:
o Requirements to set dash response: Vehicle Stopped, Neutral Mode,
Shift Device Not Neutral, and Trans Air Pressure 235 C
o Dash response was: “Clutch Temp Over Limit Allowed” now “Clutch
Overheated Allow Clutch to Cool”

•

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Service Bulletin – Product

Refer to OEM guidelines regarding the display message reset procedure.
Affected Models/Population:
• Endurant Transmissions
Warranty Information:
Informational only.
Item A:
Endurant Installation Guide link, go to Section 6: Pneumatic System Requirements.

The material contained in this bulletin is product improvement information. Eaton Corporation is not committed to,
FSUD: 2018-FSUD-2651
or liable for, canvassing existing products.

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