Near-Luxury Platform Telemetry

GMC OBD-II Diagnostics & Fault Codes

Factory diagnostic trouble code directory for GMC vehicles (Sierra 1500, Yukon, Acadia, Canyon). Access model-specific sensor tolerances, live freeze-frame telemetry, and verified DIY repair procedures.

Reliability Index

Medium-High

Industry Standard

Dealership Labor Rate

$125/hr

National Average

Avg. Sensor Cost

$85 - $150

OEM Direct Replacement

Protocol Standards

ISO 15765-4 CAN

SAE J1979 Compliant

Model Selection

Select Your GMC Model (2 Supported)

Near-Luxury

2020–2026Truck

GMC Sierra 1500

5.3L / 6.2L EcoTec3 V8 (Denali 420HP) / 3.0L Duramax Turbo-Diesel

DLC Port GuideDTC Codes

Luxury

2021–2026SUV

GMC Yukon

5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax

DLC Port GuideDTC Codes

Brand Telemetry

Most Common GMC Check Engine Trouble Codes

P0420GMC Specific

Est. DIY Parts: $400 - $1,800 (DIY: $150 - $400)

P0420 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0420: P0420: Catalyst System Efficiency Below Threshold (Bank 1) specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

P0300GMC Specific

Est. DIY Parts: $100 - $600 (DIY: $30 - $120)

P0300 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0300: P0300: Random or Multiple Cylinder Misfire Detected specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

P0171GMC Specific

Est. DIY Parts: $80 - $350 (DIY: $15 - $70)

P0171 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0171: P0171: System Too Lean (Bank 1) specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

P0128GMC Specific

Est. DIY Parts: $120 - $300 (DIY: $25 - $60)

P0128 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0128: P0128: Coolant Temperature Below Thermostat Regulating Temperature specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

P0442GMC Specific

Est. DIY Parts: $25 - $200 (DIY: $15)

P0442 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0442: EVAP System Small Leak Detected - Diagnosis & Repair Guide specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

P0500GMC Specific

Est. DIY Parts: $140 - $340 (DIY: $30 - $75)

P0500 on GMC: Symptoms & Fix

Factory troubleshooting procedure for P0500: P0500: Vehicle Speed Sensor (VSS) Malfunction specifically affecting GMC (Sierra 1500, Yukon).

5-Step OEM FixDiagnose GMC

Full Diagnostic Library

All OBD-II Codes for GMC

Showing 1–18 of 122 codes

Active:

1. Filter by Vehicle Manufacturer (25 Makes)

2. DTC System Category

3. Risk Severity Level

P0300Critical Severity

Est. DIY: $100 - $600 (DIY: $30 - $120)

P0300: Random or Multiple Cylinder Misfire Detected

Flashing Check Engine Light (CEL) • Engine shaking, vibrating, or jerking at idle

5 Step DIY GuideTroubleshoot

P0420Medium Severity

Est. DIY: $400 - $1,800 (DIY: $150 - $400)

P0420: Catalyst System Efficiency Below Threshold (Bank 1)

Illuminated Check Engine Light (steady) • Rotten egg / sulfur odor from exhaust

5 Step DIY GuideTroubleshoot

P0171Medium Severity

Est. DIY: $80 - $350 (DIY: $15 - $70)

P0171: System Too Lean (Bank 1)

Check Engine Light on • Rough idling or engine hesitation on acceleration

5 Step DIY GuideTroubleshoot

P0128Low Severity

Est. DIY: $120 - $300 (DIY: $25 - $60)

P0128: Coolant Temperature Below Thermostat Regulating Temperature

Check Engine Light • Cabin heater takes too long to warm up

5 Step DIY GuideTroubleshoot

P0455Low Severity

Est. DIY: $15 - $250 (DIY: $15 - $50)

P0455: Evaporative Emission Control System Leak Detected (Gross Leak)

Check Engine Light on • Gas cap loose warning message on dashboard

5 Step DIY GuideTroubleshoot

P0101Medium Severity

Est. DIY: $45 - $220 (DIY Clean: $12)

Mass Air Flow (MAF) Sensor Circuit Range/Performance

Check Engine Light (CEL) illuminated • Rough or erratic engine idle

4 Step DIY GuideTroubleshoot

P0135Low to Medium Severity

Est. DIY: $80 - $240 (DIY Sensor: $45)

O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)

Check Engine Light on • Slightly increased fuel consumption on short trips

3 Step DIY GuideTroubleshoot

P0172Medium Severity

Est. DIY: $30 - $280 (DIY Clean: $15)

System Too Rich (Bank 1) - Symptoms, Causes & Step-by-Step Fix

Check Engine Light on • Strong unburnt fuel odor from exhaust

3 Step DIY GuideTroubleshoot

P0442Low Severity

Est. DIY: $25 - $200 (DIY: $15)

EVAP System Small Leak Detected - Diagnosis & Repair Guide

Check Engine Light on • Intermittent faint fuel odor near rear wheel well

3 Step DIY GuideTroubleshoot

P0507Medium Severity

Est. DIY: $40 - $250 (DIY Throttle Relearn: $0)

Idle Control System RPM Higher Than Expected - Diagnosis

Engine idles at 1,000+ RPM in park/neutral • RPM surges or hunts at red lights

3 Step DIY GuideTroubleshoot

P0010Moderate Severity

Est. DIY: $120 - $350 (DIY: $40 - $80)

P0010: Camshaft Position Actuator Circuit / Open (Bank 1)

System alert or indicator light illuminated (P0010) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0011High Severity

Est. DIY: $150 - $450 (DIY: $50 - $120)

P0011: Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)

System alert or indicator light illuminated (P0011) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0012High Severity

Est. DIY: $150 - $450 (DIY: $50 - $120)

P0012: Camshaft Position - Timing Over-Retarded (Bank 1)

System alert or indicator light illuminated (P0012) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0013Moderate Severity

Est. DIY: $120 - $320 (DIY: $40 - $75)

P0013: Exhaust Camshaft Position Actuator Circuit / Open (Bank 1)

System alert or indicator light illuminated (P0013) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0014High Severity

Est. DIY: $150 - $420 (DIY: $45 - $90)

P0014: Exhaust Camshaft Position Timing Over-Advanced (Bank 1)

System alert or indicator light illuminated (P0014) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0016Critical Severity

Est. DIY: $300 - $1,200 (DIY: $80 - $250)

P0016: Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)

System alert or indicator light illuminated (P0016) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0017Critical Severity

Est. DIY: $300 - $1,200 (DIY: $80 - $250)

P0017: Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)

System alert or indicator light illuminated (P0017) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

P0100Moderate Severity

Est. DIY: $100 - $300 (DIY: $15 - $80)

P0100: Mass or Volume Air Flow Circuit Malfunction

System alert or indicator light illuminated (P0100) • Intermittent performance throttling or unexpected operation halts

5 Step DIY GuideTroubleshoot

Technical FAQ

Frequently Asked Questions

What are the most common Check Engine fault codes on GMC vehicles?

On GMC vehicles, the most frequently logged diagnostic trouble codes are P0420 (Catalytic Converter Efficiency), P0300 (Random Misfire), P0171 (System Lean), and P0128 (Coolant Thermostat).

How much does a dealer diagnostic scan cost for a GMC?

Standard diagnostic fees at authorized GMC dealerships range from $120 to $180, aligned with their $125/hr standard hourly labor rate. Independent auto parts stores can read codes for free.

Can I clear a GMC Check Engine light with an OBD-II scanner?

Yes, any standard OBD-II / EOBD scanner connected to the 16-pin DLC port can clear logged DTC codes and turn off the Check Engine light once the underlying mechanical defect has been resolved.