JEEP • 2021–2026Near-Luxury

Jeep Grand Cherokee OBD-II Diagnostic Guide

Comprehensive diagnostic trouble code telemetry, sensor voltage thresholds, and step-by-step repair manuals for Jeep Grand Cherokee models equipped with 3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP).

DLC OBD-II Port: Under driver side dashboard above foot pedals

2021–2026

Engine Powertrain

3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)

Factory Tolerances

Dealership Labor Rate

$125/hr

Jeep Certified Shop

O2 / MAF Sensor Part

$90 - $155

Direct-Fit OEM Unit

Diagnostic Protocol

SAE J1979 / ISO 15765

16-Pin DLC Gateway

Other Jeep Vehicle Models:

Jeep Grand Cherokee Jeep Wrangler

Model-Specific Telemetry

Top Check Engine Trouble Codes for Jeep Grand Cherokee

P0420Grand Cherokee Specific

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

P0420 on Jeep Grand Cherokee: Diagnosis & Fix

Troubleshooting procedure for P0420: P0420: Catalyst System Efficiency Below Threshold (Bank 1) specifically affecting Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

5-Step DIY GuideFix Grand Cherokee

P0300Grand Cherokee Specific

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

P0300 on Jeep Grand Cherokee: Diagnosis & Fix

Troubleshooting procedure for P0300: P0300: Random or Multiple Cylinder Misfire Detected specifically affecting Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

5-Step DIY GuideFix Grand Cherokee

P0171Grand Cherokee Specific

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

P0171 on Jeep Grand Cherokee: Diagnosis & Fix

Troubleshooting procedure for P0171: P0171: System Too Lean (Bank 1) specifically affecting Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

5-Step DIY GuideFix Grand Cherokee

P0128Grand Cherokee Specific

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

P0128 on Jeep Grand Cherokee: Diagnosis & Fix

Troubleshooting procedure for P0128: P0128: Coolant Temperature Below Thermostat Regulating Temperature specifically affecting Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

5-Step DIY GuideFix Grand Cherokee

P0520Grand Cherokee Specific

Est. DIY Parts: $130 - $320 (DIY: $25 - $60)

P0520 on Jeep Grand Cherokee: Diagnosis & Fix

Troubleshooting procedure for P0520: P0520: Engine Oil Pressure Sensor/Switch Circuit Malfunction specifically affecting Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)).

5-Step DIY GuideFix Grand Cherokee

Full Diagnostic Library

All OBD-II Codes for Jeep Grand Cherokee

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

Where is the OBD-II diagnostic port located on the Jeep Grand Cherokee?

On the Jeep Grand Cherokee (2021–2026), the standard 16-pin DLC port is located: Under driver side dashboard above foot pedals. It supports SAE J1979 / ISO 15765-4 CAN protocols for all handheld OBD-II code readers.

What are the most common Check Engine fault codes on the Jeep Grand Cherokee?

The most frequently logged trouble codes on the Jeep Grand Cherokee (3.6L Pentastar V6 (293HP) / 5.7L HEMI V8 / 4xe PHEV (375HP)) include P0420, P0300, P0171, P0128.

How much does an OBD-II diagnostic scan cost for a Jeep Grand Cherokee?

Most auto parts retailers (AutoZone, O'Reilly, Advance Auto) offer basic code reading free of charge. Dealership diagnostic scan fees average $120 to $180 based on Jeep's standard $125/hr labor rate.