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P0172 on Cadillac CT5: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code P0172 (System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix) specifically on the Cadillac CT5 (2020–2026, 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP)).

Cadillac CT5
DIY Parts Estimate
$30 - $280 (DIY Clean: $15)
CT5 OEM Fitment
Shop Labor Quote
$180 – $380
Based on $165/hr labor
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check P0172 On Another Cadillac Model:
Cadillac EscaladeCadillac Escalade-VCadillac CT5Cadillac CT5-V BlackwingCadillac XT5Cadillac Lyriq

1. Symptoms of P0172 on Cadillac CT5

When the Engine Control Module (ECM/PCM) on your Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP)) logs fault code P0172, drivers commonly observe:

Check Engine Light on on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Strong unburnt fuel odor from exhaust on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Black carbon soot around exhaust tip on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Rough idle and engine bogging under throttle on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Noticeable drop in MPG on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Cadillac CT5 OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell lower bezel near hood release. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Cadillac CT5

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

55%
Faulty or leaking fuel injector (Cadillac OEM Part)
25%
Contaminated Mass Air Flow (MAF) sensor (Cadillac OEM Part)
12%
Stuck closed EVAP canister purge valve (Cadillac OEM Part)
8%
Excessive fuel pressure regulator failure (Cadillac OEM Part)

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

01
Clean MAF Sensor and Throttle Body

Use dedicated MAF cleaner to remove carbon buildup from sensor wires. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

02
Check Short Term & Long Term Fuel Trims

Use live OBD-II scanner data; negative trims beyond -10% indicate the ECU is cutting fuel. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

03
Inspect Fuel Injector Leak-Down

Perform a fuel pressure leak-down test to identify injectors leaking raw gasoline into cylinders while parked. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Other Common Fault Codes on Cadillac CT5

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

4. Cadillac CT5 P0172 FAQs

What causes code P0172 to trigger on a Cadillac CT5?

On the Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP)), P0172 is most frequently caused by Faulty or leaking fuel injector or Contaminated Mass Air Flow (MAF) sensor.

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

On the Cadillac CT5, the 16-pin DLC diagnostic connector is located Driver footwell lower bezel near hood release. 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 with code P0172?

Driveable short distances, but unburnt fuel can damage catalytic converters. Given that P0172 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.