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P0300 on Cadillac CT5-V Blackwing: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0300 (P0300: Random or Multiple Cylinder Misfire Detected) specifically on the Cadillac CT5-V Blackwing (2022–2026, 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)).

Cadillac CT5-V Blackwing
DIY Parts Estimate
$100 - $600 (DIY: $30 - $120)
CT5-V Blackwing OEM Fitment
Shop Labor Quote
$180 – $380
Based on $165/hr labor
Drivability Status
Not Recommended
Critical urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0300 On Another Cadillac Model:
Cadillac EscaladeCadillac Escalade-VCadillac CT5Cadillac CT5-V BlackwingCadillac XT5Cadillac Lyriq

1. Symptoms of P0300 on Cadillac CT5-V Blackwing

When the Engine Control Module (ECM/PCM) on your Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)) logs fault code P0300, drivers commonly observe:

Flashing Check Engine Light (CEL) on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Engine shaking, vibrating, or jerking at idle on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Noticeable loss of engine power when accelerating on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Strong gasoline smell from exhaust or poor fuel economy on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Stumbling or stalling at stoplights on Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto))
Cadillac CT5-V Blackwing OBD-II Port Location
The 16-pin diagnostic connector is located Driver A-pillar base kick panel. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Cadillac CT5-V Blackwing

Historical warranty claims and technical repair bulletins for Cadillac CT5-V Blackwing point to the following failure distribution:

55%
Worn or fouled spark plugs and damaged spark plug wires (Cadillac OEM Part)
25%
Failing ignition coils or coil packs (Cadillac OEM Part)
12%
Clogged fuel injectors or low fuel rail pressure (Cadillac OEM Part)
8%
Intake manifold vacuum leak (Cadillac OEM Part)
8%
Low engine compression or faulty Camshaft/Crankshaft sensor (Cadillac OEM Part)

3. Step-by-Step DIY Repair Guide for Cadillac CT5-V Blackwing

01
Scan with OBD-II Scanner for Accompanying Codes

Plug a handheld OBD-II scanner into the 16-pin port under the dashboard. Check if specific cylinder codes like P0301 (Cylinder 1) or P0304 (Cylinder 4) accompany P0300. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: OBD-II Code Reader / Scanner
02
Inspect and Replace Spark Plugs

Remove the ignition coils, use a spark plug socket with ratchet to unthread spark plugs. Inspect electrode tips for carbon buildup, oil fouling, or burnt gaps. Replace with OEM iridium plugs gapped to spec. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: 5/8 Spark Plug Socket, Ratchet Extension, Gap Gauge
03
Test Ignition Coils

Perform an ignition swap test: Swap coil from a suspected misfiring cylinder to an adjacent cylinder. Clear codes and re-scan. If the misfire moves, replace the faulty coil. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: 10mm Socket, Multimeter
04
Check for Vacuum Leaks

Inspect PCV hoses, intake boot, and vacuum lines for cracking or hissing sounds while engine idles. Smoke test the intake if necessary. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: Carb cleaner spray or Smoke machine
05
Verify Fuel Delivery and Clear DTC Codes

Add a bottle of premium fuel injector cleaner (e.g. Chevron Techron). Clear the OBD-II codes with your scanner and take the car on a 15-minute drive cycle to confirm readiness monitors reset. on the Cadillac CT5-V Blackwing equipped with 6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto).

Required Tool: OBD-II Scanner

Other Common Fault Codes on Cadillac CT5-V Blackwing

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Cadillac CT5-V Blackwing:

4. Cadillac CT5-V Blackwing P0300 FAQs

What causes code P0300 to trigger on a Cadillac CT5-V Blackwing?

On the Cadillac CT5-V Blackwing (6.2L Handbuilt Supercharged LT4 V8 (668HP / 659 lb-ft / 6-Speed Manual / 10-Speed Auto)), P0300 is most frequently caused by Worn or fouled spark plugs and damaged spark plug wires or Failing ignition coils or coil packs.

Where is the OBD-II port located on my Cadillac CT5-V Blackwing?

On the Cadillac CT5-V Blackwing, the 16-pin DLC diagnostic connector is located Driver A-pillar base kick panel. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Cadillac CT5-V Blackwing with code P0300?

No. Driving with a flashing check engine light causes irreversible catalytic converter damage. Given that P0300 carries a Critical severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.