Cummins fault code 1691 is the official Cummins troubleshooting manual for the Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency fault on ISX11.9 CM2250 engines. This 15-page PDF documents SPN 100, FMI 18, and the amber-lamp response, and it walks through the circuit description, the guided diagnostic steps, and the exact conditions for setting and clearing the code. The aftertreatment system is monitored by three exhaust temperature sensors: the diesel oxidation catalyst intake, the diesel particulate filter intake, and the filter outlet. The ECM compares these readings to judge catalyst conversion efficiency.
Official document details
| Brand | Cummins |
| Model coverage | ISX11.9 CM2250 and ISX12 CM2250 (2010–2012) |
| System / Group | Diagnostic Trouble Codes (DTCs) — Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency |
| Fault code | 1691 (SPN 100, FMI 18) |
| Fault description | Aftertreatment Diesel Oxidation Catalyst Conversion Efficiency — Data Valid But Below Normal Operating Range – Moderately Severe Level |
| Warning lamp | Amber |
| Reference | Cummins INSITE service tool; Procedure 019-032 (ECM Calibration Code) |
| Pages | 15 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Cummins fault code 1691 table of contents
- Overview and circuit description
- Component location
- Conditions for running the diagnostics
- Conditions for setting fault code 1691
- Action taken when the fault code is active
- Conditions for clearing the fault code
- Shop Talk service notes
- Guided troubleshooting steps and associated procedures
Applicable truck models and engines
This document applies to Cummins ISX11.9 CM2250 and ISX12 CM2250 engines from the 2010–2012 range fitted in heavy-duty on-highway trucks. The SPN 100 / FMI 18 definition and the guided steps follow the same fault-code logic Cummins publishes for its CM2250 platform, so always confirm the ECM calibration on the vehicle against the current revision using the Cummins INSITE electronic service tool. Verify engine coverage on the Cummins official website before ordering parts.
Who needs this Cummins fault code 1691 manual
Any technician or workshop owner diagnosing Cummins fault code 1691 on an ISX11.9 CM2250 engine needs this procedure to work through the fault correctly. Low conversion efficiency is diagnosed against the temperature-sensor readings, fuel dosing, and exhaust leaks before the catalyst is condemned. The manual ends with the associated-procedures table and the “Reset All Faults” clearing steps so the repair can be validated.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it.
Related manuals library documents
Sản phẩm liên quan cho hãng này
Cùng brand theo taxonomy hiện có trong catalog WooCommerce.
Cummins Calterm Version 5.16 – Advanced ECM Control and Precision Tuning for Cummins Engines
Cummins INSITE 9.3 – The Essential Diagnostic Tool for Cummins Engines
Cummins InCal CE – The Calibration and Configuration Tool for Cummins Engines
