Turn Signal Flashing Fast in The IPC – 2021 Ford F-150

NHTSA ID Number: 10201617

Manufacturer Communication Number: TSB 21-2291

 

Summary

Some 2021 F-150 vehicles equipped with blind spot information system (BLIS) and rear lamp assemblies utilizing 2 incandescent bulbs and built on 01-Jan-2021 and through 30-Apr-2021 may experience a turn signal indicator flashing fast in the instrument panel cluster (IPC) with one or more of the rear lamp bulbs not flashing. This may be due to an incandescent rear lamp bulb not being completely inserted or has fallen out of the bulb socket. To correct the condition, follow the Service Procedure to inspect and replace the rear lamp wire harness.

 

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Model:

Ford

2021 F-150

 

Issue: Some 2021 F-150 vehicles equipped with blind spot information system (BLIS) and rear lamp assemblies utilizing 2 incandescent bulbs and built on 01-Jan-2021 and through 30-Apr-2021 may experience a turn signal indicator flashing fast in the instrument panel cluster (IPC) with one or more of the rear lamp bulbs not flashing. This may be due to an incandescent rear lamp bulb not being completely inserted or has fallen out of the bulb socket. To correct the condition, follow the Service Procedure to inspect and replace the rear lamp wire harness.

Action: Follow the Service Procedure steps to correct the condition if the vehicle meets all of the following criteria:

• 2021 F-150
• Built on 01-Jan-2021 and through 30-Apr-2021
• Equipped with BLIS and rear lamp assemblies utilizing 2 incandescent bulbs
• Turn signal indicator flashing fast in the IPC with one or more of the rear lamp bulbs not flashing.

 

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. “As Needed” indicates the part is required but the number may vary or is not a whole number; parts can be billed out as non-whole numbers, including less than 1. “If Needed” indicates the part is not mandatory.

 

Parts

Service Part Number	Quantity	Description
ML3Z-13410-B	2	Tail Lamp Harness	Package Contains 1 Piece, 2 Pieces Required
9T4Z-13466-A	If Needed	3157 Bulb	–

 

Service Procedure

1. Remove the rear lamp bulb socket on the affected side and location in the rear lamp assembly. Refer to Workshop Manual (WSM), Section 417-01, Removal and Installation, Rear lamp bulb, Steps 1 and 2 only.

2. Is the rear lamp bulb completely inserted into the bulb socket? A completely inserted bulb will have the top of the bulb connector flush with the top of the bulb socket. (Figure 1)

Figure 1

 

NOTE: If a bulb has fallen out of the bulb socket and is inside the rear lamp assembly, the loose bulb must be removed from inside the rear lamp assembly and discarded before reassembly.

(1). Yes – proceed to Step 3.

(2). No – discard the affected bulb and obtain a replacement bulb for installation later in this procedure. Proceed to Step 4.

3. Inspect the affected rear lamp bulb filament for being burned out or open. Is the affected rear lamp bulb filament burned out or open?

(1). Yes – this article does not apply.

(2). No – proceed to Step 4.

4. Remove the rear lamp assembly on the other side of the vehicle. Refer to WSM, Section 417-01. Proceed to Step 5.

5. Remove and discard the rear lamp wire harness assemblies on both sides.

(1). Using pliers, remove the rear lamp wire harness fastener from the rear lamp housing near the upper bulb socket. The metal retainer from the rear lamp wire harness fastener may remain in the lamp housing. Needle nose pliers can be used to extract and discard the metal retainer. (Figure 2)

Figure 2

 

(2). Using a tool, lift the metal tab on the connector mounting retainer to release the rear lamp wire harness connector from the rear lamp housing and lift upwards. (Figure 3)

Figure 3

 

(3). Remove the upper and lower bulb sockets from the rear lamp assemblies.

(4). Remove all rear lamp bulbs from the rear lamp wire harnesses that were removed and transfer the bulbs to the replacement rear lamp wire harnesses. Any discarded bulbs in Step 2(2) will require replacement.

(5). Secure the rear lamp wire harness fastener to the rear lamp housing near the upper bulb socket. (Figure 2)

(6). Secure the connector mounting retainer for the rear lamp wire harness connector to the rear lamp housing. (Figure 3)

(7). Install the upper stop/turn/tail/sidemarker and the lower stop/turn/tail bulb socket into the rear lamp assembly.

6. Install the rear lamp assemblies. Refer to WSM, Section 417-01.

 

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1 Affected Product

Vehicle

MAKE	MODEL	YEAR
FORD	F-150	2021

 

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1 Associated Document

Manufacturer Communications

21-2291
24 September 2021

https://www.nhtsa.gov/recalls?nhtsaId=10201617

MC-10201617-0001.pdf 146.44KB

 

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Last update on 2026-06-03 / Affiliate links / Images from Amazon Product Advertising API

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