Fault Family System: Powertrain (P-Codes) 10 SAE Codes

Turbo Speed Sensor Circuit

Diagnostic & Technical Explanation

Code P2578 (Turbocharger/Supercharger Speed Sensor A Circuit) sets when the ECM sees an open, shorted, implausible, or intermittent signal from the turbocharger or supercharger shaft-speed sensor (A or B on twin-charger engines) used to protect the compressor wheel from overspeed and to fine-tune boost control. Causes are a sensor tip contaminated by oil mist from the turbo's center housing, a corroded connector baked by turbo heat, or the sensor's air gap disturbed by bearing wear in the rotating assembly.

These 10 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 10 times.

Codes in this family (10)

Code	Definition	Repair coverage
P2578	Turbocharger/Supercharger Speed Sensor A Circuit	4 ranked fixes
P2579	Turbocharger/Supercharger Speed Sensor A Circuit Range/Performance	4 ranked fixes
P2580	Turbocharger/Supercharger Speed Sensor A Circuit Low	4 ranked fixes
P2581	Turbocharger/Supercharger Speed Sensor A Circuit High	4 ranked fixes
P2582	Turbocharger/Supercharger Speed Sensor A Circuit Intermittent	4 ranked fixes
P2593	Turbocharger Speed Sensor B Circuit	4 ranked fixes
P2594	Turbocharger Speed Sensor B Circuit Range/Performance	4 ranked fixes
P2595	Turbocharger Speed Sensor B Circuit Low	4 ranked fixes
P2596	Turbocharger Speed Sensor B Circuit High	4 ranked fixes
P2597	Turbocharger Speed Sensor B Circuit Intermittent	4 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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