Fault Family System: Powertrain (P-Codes) 6 SAE Codes

EGT Sensor Correlation

Diagnostic & Technical Explanation

P20E2 (Exhaust Gas Temperature Sensor 1/2 Correlation Bank 1) compares two exhaust gas temperature sensor positions along the same bank and flags an implausible relationship between them — for example, a downstream sensor reading hotter than the sensor ahead of it with no regeneration event underway. A sensor with a slow-responding or drifted element, a sensor installed in the wrong bung position after service work, and exhaust gas leaking past a loose sensor threading are the typical causes.

These 6 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 6 times.

Codes in this family (6)

Code	Definition	Repair coverage
P20E2	Exhaust Gas Temperature Sensor 1/2 Correlation Bank 1	3 ranked fixes
P20E3	Exhaust Gas Temperature Sensor 1/3 Correlation Bank 1	3 ranked fixes
P20E4	Exhaust Gas Temperature Sensor 2/3 Correlation Bank 1	3 ranked fixes
P20E5	Exhaust Gas Temperature Sensor 1/2 Correlation Bank 2	3 ranked fixes
P24C2	Exhaust Gas Temperature Measurement System - Multiple Sensor Correlation Bank 1	3 ranked fixes
P24C3	Exhaust Gas Temperature Measurement System - Multiple Sensor Correlation Bank 2	3 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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