Fault Family System: Powertrain (P-Codes) 4 SAE Codes

Throttle Airflow Detected Fault

Diagnostic & Technical Explanation

Code P2172 (Throttle Actuator Control System - Sudden High Air Flow Detected) is set when the ECM calculates that more or less air is entering the engine than the throttle plate's commanded angle should allow, comparing MAF/MAP-derived airflow against expected throttle-body flow. An unmetered vacuum leak downstream of the throttle plate, a throttle plate not fully closing due to carbon buildup, and a sticking or torn throttle body gasket are the most common physical causes.

These 4 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 4 times.

Codes in this family (4)

Code	Definition	Repair coverage
P2172	Throttle Actuator Control System - Sudden High Air Flow Detected	3 ranked fixes
P2173	Throttle Actuator Control System - High Air Flow Detected	3 ranked fixes
P2174	Throttle Actuator Control System - Sudden Low Air Flow Detected	3 ranked fixes
P2175	Throttle Actuator Control System - Low Air Flow Detected	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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