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

NH3 Sensor Heater Circuit

Diagnostic & Technical Explanation

Code P24E6 (NH3 Sensor Heater Circuit/Open) sets when the ECM detects an open circuit, out-of-range current, or a heater-performance fault while driving the heater that brings the NH3 sensor's ceramic element to operating temperature. Because the heater is sealed inside the sensor body, a genuine heater failure requires a complete sensor replacement, but the heater fuse and connector should be checked first since they are far less expensive to repair.

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
P24E6	NH3 Sensor Heater Circuit/Open	3 ranked fixes
P24E7	NH3 Sensor Heater Circuit Low	3 ranked fixes
P24E8	NH3 Sensor Heater Circuit High	3 ranked fixes
P24E9	NH3 Sensor Heater Circuit Performance	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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