TECHNICAL SERVICE BULLETIN
3.5/3.7L - Lack Of Heat Or Uneven Heat From The Front Vents

20-2053
28 February
2020

This bulletin supersedes 19-2097. Reason for update: Incorrect or Missing Parts
Model:
Ford
2015-2019 Transit

Assembly Plant: Kansas City Assembly Plant
Engine: 3.5L
Engine: 3.7L

Summary
This article supersedes TSB 19-2097 to update the Parts List.
Issue: Some 2015-2019 Transit vehicles equipped with a 3.5L or 3.7L engine may exhibit a lack of heat or
uneven heat from side to side. This condition may be due to deposits from the engine coolant becoming
trapped in the heater core. To correct the condition, flush the cooling system and replace the heater core.
Action: Follow the Service Procedure steps to correct the condition on vehicles that meet all of the
following criteria:
• 2015-2019 Transit
• 3.5L or 3.7L engine
• Lack of heat or uneven heat from side to side
NOTE: Part quantity refers to the number of that service part number required, which may be
different than the number of individual pieces. Service part numbers contain 1 piece unless
otherwise stated.
Parts
Part
Number

Description

BR3Z-8255A

-

6103599

-

CK4Z18476-A

-

6E5Z19B596-A

-

W711137S442

Package Contains 4
Pieces, 1 Piece Required

Steering Shaft Pinch Bolt

FPS 8262

Package Contains 25
Pieces, 1 Piece Required

Authorized Modification Label

VC-1

-

YN-12-D

-

Thermostat O-Ring Seal
Left A-pillar Trim Panel - Refer To The Parts
Catalog For The VIN Specific Application
Heater Core
A/C Evaporator O-Ring Kit

Quantity
1
1
1
1
1
1

Motorcraft® Premium Cooling System Flush

As
Needed

Motorcraft® PAG Refrigerant Compressor Oil

As
Needed

VC-13-G

-

Motorcraft® Yellow Concentrated
Antifreeze/Coolant (All Markets Except Canada)

2

CVC-13-G

-

Motorcraft® Yellow Concentrated
Antifreeze/Coolant (Canada Only)

2

Obtain
Locally

-

As
Needed

Distilled Water

Warranty Status: Eligible under provisions of New Vehicle Limited Warranty (NVLW)/Service Part
Warranty (SPW)/Special Service Part (SSP)/Extended Service Plan (ESP) coverage. Limits/policies/prior
approvals are not altered by a TSB. NVLW/SPW/SSP/ESP coverage limits are determined by the
identified causal part and verified using the OASIS part coverage tool.
Labor Times
Operation
No.

Description
2015-2019 Transit 3.5L/3.7L: Diagnose And Flush The Cooling System Includes
Time To Replace The Heater Core (Do Not Use With Any Other Labor Operations)

202053A

Time
9.3
Hrs.

Repair/Claim Coding
Causal Part:

18472

Condition Code: 49

Service Procedure
1. Run the engine until it reaches normal operating temperature. Does the vehicle exhibit a lack of heat or
uneven heat from the vents in the instrument panel?
(1). Yes - proceed to Step 2.
(2). No - this article does not apply. Refer to Workshop Manual (WSM), Section 412-00.
2. Select the FLOOR position on the control assembly. Set the temperature control to full warm and the
fan speed to medium setting.
3. Increase the engine speed to 3,500 revolutions per minute (RPM). After 30 seconds, allow the engine to
return to idle for an additional 30 seconds.
4. Using a suitable temperature measuring device, check the heater core inlet hose temperature. Is the
heater core inlet hose temperature above 66°C (150°F)?
(1). Yes - proceed to Step 5.
(2). No - this article does not apply. Refer to WSM, Section 412-00.
5. Measure the heater core inlet and outlet hose temperature. Are the hose temperatures within 6-17°C
(10-30°F)?
(1). Yes - this article does not apply. Refer to WSM, Section 412-00.
(2). No - proceed to Step 6.
6. Drain the engine coolant. Refer to WSM, Section 303-03.
7. Remove the coolant hoses from the transmission fluid cooler. Refer to WSM, Section 307-02.
8. Remove the thermostat. Refer to WSM, Section 303-03.
9. Disconnect the lower radiator hose.
10. Using a garden hose, flush inlet and outlet radiator hoses for 2 minutes each.
11. Reassemble the thermostat housing without the thermostat installed. Do not reconnect radiator hoses
to the housing at this time.

12. Using a garden hose, flush the degas bottle for 2 minutes.
13. Close the radiator drain valve.
14. Reattach the coolant hoses to the transmission fluid cooler.
15. Disconnect the inlet and outlet heater hoses from the heater core. Refer to WSM, Section 412-00.
16. Using a garden hose, flush inlet and outlet heater hoses back toward the engine for 5 minutes each.
17. Reattach all hoses except for the inlet and outlet heater hoses.
18. Using pinch pliers, clamp off inlet and outlet heater hoses.
19. Add 1 bottle of Motorcraft® Premium Cooling System Flush and fill the rest of the cooling system with
water.
20. Connect the appropriate Ford scan tool to the vehicle and start the engine.
21. Allow the engine to reach normal operating temperature.
22. Run the engine at 2,500 RPM for 15 minutes with the climate control system off.
23. Return the engine to idle. Using the Ford scan tool, command the cooling fans on high speed for 5
minutes.
24. Turn the engine off and open the degas bottle cap carefully as the water may be hot. Refer to WSM,
Section 303-03.
25. Drain the cooling system. Refer to WSM, Section 303-03.
26. Remove the coolant hoses from the transmission fluid cooler.
27. Using a garden hose, flush the degas bottle at the cap opening for 2 minutes.
28. Close the radiator drain valve.
29. Reattach the coolant hoses to the transmission fluid cooler.
30. Fill the cooling system with water. Refer to WSM, Section 303-03.
31. Repeat Steps 20 through 27.
32. Remove the pinch pliers from the inlet and outlet heater core hoses and backflush toward the engine
with a garden hose for 1 minute each.
33. Using a garden hose, flush the transmission fluid cooler coolant inlet and outlet with water for 1 minute
each.
34. Using a garden hose, flush the degas bottle at the cap opening for 2 minutes.
35. If equipped, disconnect the coolant hoses from the engine oil cooler and flush the inlet and outlet ports
of the cooler with water for 1 minute each. Reconnect the hoses. Refer to WSM, Section 303-01.
36. Remove the plug from the left side of the engine block to aid with cooling system drainage. (Figure 1)
Figure 1

37. Reinstall the block plug and close the radiator drain.
38. Install the thermostat. Refer to WSM, Section 303-03.
39. Reconnect the coolant hoses to the transmission fluid cooler.
40. If equipped, disconnect and backflush all rear heater components and hoses with a garden hose for 2
minutes.
41. Replace the heater core. Clean the heater core inlet and outlet metal tubes with hot water until free of
deposits. Refer to WSM, Section 412-00.
42. Fill the cooling system using Motorcraft® Yellow Concentrated Antifreeze/Coolant. Refer to WSM,
Section 303-03 to determine correct coolant concentration based on the climate.
43. Fill out the Authorized Modification Label with the following text: "Use Only Motorcraft® Yellow
Antifreeze/Coolant".
44. Clean the coolant reservoir surface with isopropyl alcohol and apply the Authorized Modification Label.
45. Advise the owner or driver that the unit will be using a different coolant (Motorcraft® Yellow
Antifreeze/Coolant) for the environmental conditions. Highlight the coolant used on the customer's copy
of the repair order.

© 2020 Ford Motor Company
All rights reserved.
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge,
tools, and equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or
provides information that could assist in proper vehicle service. The procedures should not be performed by "do-it-yourselfers". Do
not assume that a condition described affects your car or truck. Contact a Ford or Lincoln dealership to determine whether the
Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation determine Warranty and/or Extended
Service Plan coverage unless stated otherwise in the TSB article. The information in this Technical Service Bulletin (TSB) was
current at the time of printing. Ford Motor Company reserves the right to supersede this information with updates. The most recent
information is available through Ford Motor Company's on-line technical resources.