This page lists 3 electrical bulb & socket parts for the 2021 Cadillac CT4, across 1 part type, covering both the 2.0L L4 Turbocharged and the 2.7L L4 Turbocharged. Every part shows its brand, manufacturer part number and fitment notes.
The bulb and socket system on the 2021 Cadillac CT4 covers every bulb and socket on the vehicle, from headlamps to instrument-cluster illumination. Every listed part is a Turn Signal Lamp Bulb.
The 2021 Cadillac CT4 was sold with both the 2.0L L4 Turbocharged and the 2.7L L4 Turbocharged. Every part on this page is engine-specific. Each part shows which engine(s) it fits.
The most listed brands for 2021 Cadillac CT4 electrical bulb & socket parts are PHILIPS (1 part), SYLVANIA (1 part) and GM GENUINE (1 part). Quality grades include Extended Life and Standard Replacement.
Each part number listed for the 2021 Cadillac CT4 opens a page with every vehicle that part fits.
Turn Signal Lamp Bulb
Extended Life
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| PHILIPS Fits: 2.7L L4 Turbocharged | 7444NALL | 🇺🇸 US 🇨🇦 CA | Longer LifeNatural Amber | View on Amazon |
| SYLVANIA Fits: 2.7L L4 Turbocharged | 7444NALL | 🇺🇸 US 🇨🇦 CA | Long LifeAmber | View on Amazon |
Standard Replacement
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| GM GENUINE Fits: 2.7L L4 Turbocharged | 13579188 | 🇺🇸 US 🇨🇦 CA | Trade # 7444NAAmber Glass Bulb | View on Amazon |
This table covers the bulbs in the turn-signal lamps. Typical signs include a dark lamp, flicker, or a bulb that keeps failing in one socket. If the same position keeps failing, replace the socket or repair the ground rather than chasing bulbs.
3 Turn Signal Lamp Bulb parts are listed for the 2021 Cadillac CT4, from PHILIPS, SYLVANIA and GM GENUINE.
The Extended Life section lists 2 options from PHILIPS and SYLVANIA — grouped under the catalog's "Extended Life" designation — the notes column spells out what sets them apart. PHILIPS 7444NALL is listed in this group.
The Standard Replacement section lists 1 option from GM GENUINE — built to original-equipment specification. GM GENUINE 13579188 is listed in this group.
Listed part numbers: PHILIPS 7444NALL and GM GENUINE 13579188, plus the other parts above.
Buying Electrical Bulb & Socket Parts for a 2021 Cadillac CT4
On this vehicle, the bulb and socket system covers every bulb and socket on the vehicle, from headlamps to instrument-cluster illumination.
- Match the engine first. Every electrical bulb & socket part here is engine-specific; each row shows which engine(s) it fits.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace bulbs in pairs so both sides age together, and put a smear of dielectric grease on the new socket contacts.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Turn Signal Lamp Bulb .
Frequently Asked Questions
How many electrical bulb & socket parts fit the 2021 Cadillac CT4?
Our catalog currently lists 3 electrical bulb & socket parts for the 2021 Cadillac CT4 across 1 subcategory and 3 brands, covering both the 2.0L L4 Turbocharged and the 2.7L L4 Turbocharged. Each part is matched to the engine(s) it fits.
Do electrical bulb & socket parts differ between 2021 Cadillac CT4 engines?
Yes. Every electrical bulb & socket part on this page is engine-specific. Each row shows which engine(s) it fits — use the filter at the top to hide the rest. If you're unsure which engine you have, check the emissions label under the hood or the 8th character of your VIN.
What are the signs of electrical bulb & socket problems on a 2021 Cadillac CT4?
Common symptoms include a lamp that flickers over bumps, melted or discolored socket plastic, or bulbs that keep failing early on one side. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What should I replace at the same time?
Where labor overlaps, replace bulbs in pairs so both sides age together, and put a smear of dielectric grease on the new socket contacts.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 2021 Cadillac CT4 was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 2021 Cadillac CT4?
First match the engine — each row shows which engine(s) the part fits. Then repeated bulb failure in one position usually means a socket or ground problem, not bad bulbs — replace the socket rather than chase it. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 2021 Cadillac CT4
Electrical Bulb & Socket Parts for Other Cadillac CT4 Years
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Manufacturer names, model designations and part numbers are used for identification and fitment reference only. AutoFactsDB is an independent catalog and is not affiliated with, endorsed by, or sponsored by any vehicle manufacturer displayed on this page.