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C0045 on Cadillac CT5: Fix & DLC Location

Factory diagnostic troubleshooting wire for fault code C0045 (C0045: Left Rear Wheel Speed Sensor Circuit Malfunction) 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
$120 - $320 (DIY: $30 - $70)
CT5 OEM Fitment
Shop Labor Quote
$180 – $380
Based on $165/hr labor
Drivability Status
Drivable (Short Trip)
High urgency level
Est. DIY Time
45 – 90 Min
Basic hand tools
Check C0045 On Another Cadillac Model:
Cadillac EscaladeCadillac Escalade-VCadillac CT5Cadillac CT5-V BlackwingCadillac XT5Cadillac Lyriq

1. Symptoms of C0045 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 C0045, drivers commonly observe:

System alert or indicator light illuminated (C0045) on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Intermittent performance throttling or unexpected operation halts on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Audible sensor relay clicking or anomalous status telemetry in dashboard logs on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Degraded operational throughput or error dialog popups on startup on Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP))
Readiness monitors failing state emissions or system compliance audits 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%
Component aging, oxidation, or degraded internal circuit element (Rear Left ABS Speed Sensor) (Cadillac OEM Part)
25%
Wiring harness abrasion, loose terminal pin, or ground voltage float (Cadillac OEM Part)
12%
Outdated firmware microcode or incompatible software driver update (Cadillac OEM Part)
8%
Thermal stress or excessive operational duty-cycle fatigue (Cadillac OEM Part)
8%
Contamination from carbon buildup, moisture ingress, or dirty filtration (Cadillac OEM Part)

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

01
Connect Diagnostic Scanner / Logging Monitor to Retrieve Telemetry

Interface with the diagnostic port or system console using verified scanning hardware. Record freeze-frame data, active sub-codes, and timestamps to isolate whether C0045 is static or intermittent. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Required Tool: Jack stands, Socket set
02
Perform Physical & Electrical Circuit Inspection

Visually inspect the physical component (Rear Left ABS Speed Sensor), connector pins, and associated wiring harnesses for signs of corrosion, thermal melting, or loose grounding clips. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Required Tool: Multimeter, Flashlight, Contact Cleaner Spray
03
Component Testing & Resistance / Voltage Verification

Measure reference voltages and resistance thresholds against manufacturer factory specifications. Replace any component failing nominal impedance tolerances. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Required Tool: Jack stands, Socket set
04
Execute Component Replacement or Software Configuration Patch

Install genuine OEM replacement hardware or execute registry / service commands. Ensure all mounting bolts are torqued to factory specifications. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Required Tool: Standard Hand Tool Set / Terminal Commands
05
Clear Diagnostic Trouble Code & Complete Verification Drive Cycle

Erase the fault code from non-volatile memory. Perform a standard verification cycle (e.g. 15-minute mixed drive or system stress benchmark) to ensure monitors reset to 'Ready' state without recurrent fault flags. on the Cadillac CT5 equipped with 2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP).

Required Tool: OBD-II Code Reader / Diagnostic Suite

Other Common Fault Codes on Cadillac CT5

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

4. Cadillac CT5 C0045 FAQs

What causes code C0045 to trigger on a Cadillac CT5?

On the Cadillac CT5 (2.0L Twin-Scroll Turbo (237HP) / 3.0L Twin-Turbo V6 (CT5-V 360HP)), C0045 is most frequently caused by Component aging, oxidation, or degraded internal circuit element (Rear Left ABS Speed Sensor) or Wiring harness abrasion, loose terminal pin, or ground voltage float.

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 C0045?

Caution. Limited operation permitted only to reach a nearby repair facility or backup critical personal files. Given that C0045 carries a High severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.