This fault code 346 DTCs document is a troubleshooting procedure for ECM calibration memory software faults caused by invalid switch configuration settings. It explains how shared OEM harness inputs or outputs can create feature conflicts in the ECM and how INSITE™ electronic service tool is used to check, correct, and clear the fault.
Official fault code 346 DTCs document details
| Brand | Cummins |
|---|---|
| Model coverage | ISB6.7 CM2250; ISC8.3 and ISL9 CM2250; also references ISX11.9 CM2250, ISX15 CM2250, GX CM2250, and QSL9 CM2250 in associated procedures |
| System/Group | ISB6.7 CM2250 (2010-12) / DTCs |
| Publication no. | Not specified in the extract |
| Year/Revision | Last modified dates shown include 20-Nov-2009, 11-Jun-2010, 20-Jul-2010, and 04-Jan-2011 |
| Pages | 18 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- FAULT CODE 145-fc346
- Fault Code Path Selection
- Overview
- Circuit Description
- Component Location
- Conditions for Running the Diagnostics
- Conditions for Setting the Fault Codes
- Action Taken When the Fault Code is Active
- Conditions for Clearing the Fault Code
- Shop Talk
- Associated Procedures
- Troubleshooting Steps
- Guided Step 1 – Check the fault codes.
- Guided Step 2 – Check the adjustable parameter settings.
- Guided Step 3 – Check ECM calibration and clear fault codes.
Applicable truck models
The extract identifies this procedure for Cummins CM2250 engine applications, including ISB6.7 CM2250, ISC8.3 and ISL9 CM2250, with Heavy Duty coverage shown for ISX11.9 CM2250 and ISX15 CM2250. The associated procedures table also references ECM Calibration Code Procedure 019-032 for ISX15 CM2250, GX CM2250, ISX11.9 CM2250, and QSL9 CM2250. The document is not a chassis-specific truck manual; it applies where these engines and their OEM harness switch input or output configurations are used. For manufacturer information, visit Cummins official website.
Who needs this fault code 346 DTCs manual
Workshop owners, diesel mechanics, and fleet technicians need this manual when Fault Code 346 is active and optional ECM switch inputs may not operate correctly. It is especially relevant after parameter changes, ECM calibration work, or feature setup involving accelerator interlock, powertrain protection torque limit, air shutoff valve, idle shutdown relay, switched maximum engine operating speed, switched maximum vehicle speed, or governor type switch functions.
The procedure directs technicians to turn the keyswitch ON, connect INSITE™ electronic service tool, read active fault codes, and inspect adjustable parameter settings. It explains that the Engine Control Module detects when two features sharing a common OEM wire are enabled at the same time. Corrective actions include disabling one conflicting feature, using SAE J1939 multiplexing where applicable, checking ECM code and revision information in System ID and Dataplate, and calibrating the ECM if a relevant update is available. The amber CHECK ENGINE lamp turns off after the diagnostic runs and passes, and “Reset All Faults” in INSITE™ can clear active and inactive faults after the repair is validated by idling the engine for 1 minute.
Full PDF available in the DiagTechPro manuals library, free account required to download.
Related manuals library
Sản phẩm liên quan cho hãng này
Cùng brand theo taxonomy hiện có trong catalog WooCommerce.

Cummins INSITE 9.3 – The Essential Diagnostic Tool for Cummins Engines

Cummins Calterm Version 5.16 – Advanced ECM Control and Precision Tuning for Cummins Engines

Cummins InCal CE – The Calibration and Configuration Tool for Cummins Engines

