AftertreatmentCaterpillar Diesel ECM

SPN

Name: ECM Performance
Address: Fort Lauderdale, FL, 33325, US
Telephone: (888) 768-2447
Price range: $$-$$$

DPF, DEF, SCR, and NOx-reduction system faults.

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System

Caterpillar Aftertreatment

Caterpillar ECM Service

Needs VerificationThis code as listed may be incomplete or non-standard (e.g. a partial code, placeholder term, or reference number rather than a confirmed fault code). Pull the exact code in the Cat ET tool before using this page for a repair decision.

Diagnostic Overview

SPN is not a complete fault code by itself. It means Suspect Parameter Number and identifies the system, sensor, or data item that the ECM is monitoring. CAT diagnostic codes usually need both the SPN and FMI to provide useful direction. Without the FMI, the same SPN could mean high voltage, low voltage, abnormal rate of change, above-normal condition, below-normal condition, or another failure type. Always capture the full SPN/FMI pair before writing service content or performing repairs.

Likely Causes

Incomplete diagnostic code; missing FMI; scanner or display only showing part of the fault; copied list not including complete detail.

What To Check First

Use Cat ET to read the complete code with SPN, FMI, occurrence count, active/inactive status, and event timestamp.

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Related Aftertreatment Fault Codes

View All Aftertreatment Codes

SPN 1761 FMI 17

CAT fault code 1761-17 commonly relates to diesel exhaust fluid level or a DEF level signal that is below the expected range.

SPN 3360 / SPN 3820

CAT codes listed as 3360/3820 generally point toward the DEF supply, DEF quality, DEF tank, or SCR dosing system depending on the exact FMI shown in Cat ET.

SPN 3361 / SPN 3821

CAT codes listed as 3361/3821 commonly belong to the DEF dosing or SCR control side of the aftertreatment system.

SPN 3474 FMI 31

CAT fault code 3474-31 is typically associated with aftertreatment regeneration or ARD-related operation.

SPN 3701 FMI 15

CAT fault code 3701-15 commonly indicates an aftertreatment condition that is above normal but at a least-severe level, often connected with DPF soot load, regeneration need, or aftertreatment restriction.

SPN 3701 FMI 16

CAT fault code 3701-16 usually represents a more serious aftertreatment condition than 3701-15, with the measured or calculated value above normal at a moderate severity level.

View All Aftertreatment Codes →