NHTSA ID Number: 10177693
Manufacturer Communication Number: SB54-331
TSB/Document Date: 2020-07-31
Summary
Freightliner
Service Bulletin for Updated ULB Control Unit for LED Headlamps. New Cascadia vehicles with light emitting diode (LED) headlamps built from January 1, 2017 through February 17, 2020 may experience intermittent disabled headlamps due to an issue with the universal light ballast (ULB). The LED headlamps can turn off if the supply voltage drops below approximately 9V. This low voltage commonly and momentarily occurs when cranking the engine on a vehicle with batteries that are not fully charged. The momentary low voltage may cause the electronic ULB control unit to malfunction. The ULB may not resume normal function until the power supply to the headlamp is disconnected.
54-331
Updated ULB Control Unit for LED Headlamps
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado
Freightliner
Service Bulletin
Business Class M2
Cascadia
108SD/114SD
> New Cascadia
General Information
New Cascadia vehicles with light emitting diode (LED) headlamps built from January 1, 2017 through February
17, 2020 may experience intermittent disabled headlamps due to an issue with the universal light ballast (ULB).
The LED headlamps can turn off if the supply voltage drops below approximately 9V. This low voltage
commonly and momentarily occurs when cranking the engine on a vehicle with batteries that are not fully
charged. The momentary low voltage may cause the electronic ULB control unit to malfunction. The ULB may
not resume normal function until the power supply to the headlamp is disconnected.
If this malfunction occurs, the entire headlamp does not need to be replaced. Replace the ULB control unit with
a new ULB, DTNA part number 66-01405-050/software number S07.70 or newer. Do not replace it with the
same or older ULB, DTNA part number 66-01405-040/software number S07.26. See Fig. 1 for software number
location.
A
S07.70
07/29/2020
f547300
A. Software Number Location
Fig. 1, Inner ULB Cover With Software Number
When replacing the ULB on one headlamp, replace the ULB on the other headlamp, if it has not previously
been replaced.
NOTE: New Cascadia vehicles built after February 17, 2020 have LED headlamps with a ULB control
unit with software that allows the headlamp to recover from low voltage as soon as voltage returns to
normal.
Parts
ULB Replacement Parts
DTNA Part
Number
ULB Software
Number
66-01405-050
07.70
Part Name
New LED Headlamp ULB Control Unit (with seal and
screws)
Table 1, ULB Replacement Parts
Freightliner Service Bulletin, 07/30/2020
Page 1
54-331
Updated ULB Control Unit for LED Headlamps
Freightliner
Service Bulletin
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado
Business Class M2
Cascadia
108SD/114SD
> New Cascadia
Work Instructions
1. Park the vehicle on a level surface, apply the parking brakes, and shut down the engine. Chock the tires.
2. Open the hood.
3. Disconnect the electrical connector from the back of the headlamp assembly.
3.1
Press down on the locking tab with a screwdriver. See Fig. 2.
04/25/2017
f546721
Fig. 2, Pressing Down on the Locking Tab
3.2
With the locking tab pressed down, remove the electrical connector from the headlamp.
NOTICE
Hold the headlamp assembly mounting stud with a Torx® tool while removing the nuts with a wrench. If
the stud spins when the nut is removed, it will unscrew from the housing and potentially damage the
assembly.
4. With an assistant supporting the headlamp assembly, remove the four mounting fasteners.
5. Remove the headlamp assembly from the vehicle.
6. Remove the ULB control unit. See Fig. 3.
6.1
Manually remove the four screws from the ULB control unit.
6.2
Remove the ULB control unit from the headlamp assembly. See Fig. 4. Dispose of the old seal.
Page 2
Freightliner Service Bulletin, 07/30/2020
54-331
Updated ULB Control Unit for LED Headlamps
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado
Freightliner
Service Bulletin
Business Class M2
Cascadia
108SD/114SD
> New Cascadia
2
1
07/21/2020
f546724a
1. Daytime Running Lights/Marker Unit
2. ULB Control Unit
Fig. 3, Headlamp Assembly (reverse side shown)
04/25/2017
f546722
NOTE: The electrical connector is integrated into the
ULB control unit.
Fig. 4, ULB Control Unit
6.3
Position the new ULB control unit on the headlamp assembly. Make sure the new ULB outer seal is
positioned correctly within the headlamp housing and verify the electrical connector is fully seated.
6.4
Manually install the four new screws and tighten them 8.9 to 13.28 lbf·in (100 to 125 N·cm).
7. To provide corrosion protection, coat the headlamp harness connector terminals with dielectric grease. See
Table 2 for approved electrical lubricants.
Approved
Manufacturer
Standard Oil Co.
Shell Oil Co.®
Texaco, Inc.®
Quaker State®
Electrical Lubricants
Lubricant or Part Number
White Vasoline
No. 71032; No. 71306
No. 955
No. NYK-77
Table 2, Approved Electrical Lubricants
8. Install the headlamp assembly on the vehicle.
8.1
Position the headlamp assembly on the vehicle.
8.2
With an assistant supporting the headlamp assembly, install the fasteners and tighten 5.5 lbf·ft (7.
25±1 N·m).
9. Connect the electrical connector to the headlamp assembly.
Freightliner Service Bulletin, 07/30/2020
Page 3
54-331
Freightliner
Service Bulletin
Updated ULB Control Unit for LED Headlamps
FLA COE
FLB COE
FLD Conventional
Business Class
FLC 112 Conventional
Century Class Conventional
Argosy
Cargo
Columbia
122SD and Coronado
Business Class M2
Cascadia
108SD/114SD
> New Cascadia
10. Check the headlamps for proper operation.
11. Verify and, if necessary, adjust the headlamp aim as described in Subject 54.04.120 of the New Cascadia
Workshop Manual.
12. Close the hood. Remove the tire chocks.
Warranty
This procedure is warrantable only if the described condition exists and the repair is performed within the
applicable base or extended coverage warranty period. If a failure is not found, this procedure is considered
preventive and warranty does not apply.
Normal warranty applies. See Table 3 for OWL VMRS codes and labor allowance information. Enter this service
bulletin number in the Service Bulletin # field.
Primary Failed Part
LED Headlamp ULB
Control Unit
LED Headlamp ULB
Control Units
OWL VMRS Codes and Labor Allowance
Component
Cause Code SRT Code
Description
Code
HEADLIGHT ULB MODULE, LED
034-001-093
03
312-5026A HEADLAMPS, ONE SIDE ONLY, R/R
(SB54-331)
HEADLIGHT ULB MODULE, LED
034-001-093
03
312-5026B HEADLAMPS, BOTH LH AND RH,
REPLACE ULBS ONLY, (SB54-331)
Time: Hours
0.3
0.5
Table 3, OWL VMRS Codes and Labor Allowance
Page 4
Freightliner Service Bulletin, 07/30/2020
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TSB/Document ID: SB54-331
Replacement Service Bulletin Number:
MFR Communication Date: 2020-07-30
MFR Internal Campaign ID/Software Version:
Communication Type: Service Bulletin/Repair Instructions
NHTSA Components: EXTERIOR LIGHTING
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