Cummins fault code 1938 is documented on this DiagTechPro library page for Cummins ISM CM871 (2007-09) engines, where it flags the Ecu Power Output Supply Voltage 1 – Data Valid but Below Normal Operational Range – Moderately Severe Level condition (PID S212, SPN 3597, FMI 1/18, Amber lamp). This 5-page PDF reproduces the manufacturer description, shop talk, component location and step-by-step troubleshooting so technicians can confirm and clear the code.
Cummins fault code 1938 overview
Cummins identifies this code as “Ecu Power Output Supply Voltage 1 – Data Valid but Below Normal Operational Range – Moderately Severe Level” on the VGT Actuator Circuit. The variable geometry turbocharger (VGT) is electronically activated by the VGT actuator. The VGT actuator is a smart device and receives information via the J1939 datalink from the primary engine ECM. The VGT actuator performs its own diagnostics and reports failures back to the primary engine electronic control module (ECM) using the J1939 datalink.
Official document details
| Brand | Cummins |
| Model coverage | Cummins ISM CM871 (2007-09); Cummins ISX CM871 (2007-09) |
| System / Group | VGT Actuator Circuit — ISM CM871 fault codes |
| Fault code | 1938 (SPN 3597, FMI 1/18) |
| PID | S212 |
| Warning lamp | Amber |
| Source | TruckFaultCodes.com Cummins fault code reference (© 2017) |
| Pages | 5 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code identification (PID, SPN, FMI, lamp)
- Description
- Shop Talk
- Component Location
- Troubleshooting Steps
Applicable truck models and engines
This document applies to Cummins ISM CM871 (2007-09); Cummins ISX CM871 (2007-09) equipped diesel engines that log Fault Code 1938. Always confirm engine calibration and use a Cummins diagnostic tool such as INSITE to read live data before replacing parts. Full specifications are published on the Cummins official website.
Who needs this Cummins fault code 1938 manual
Heavy-duty truck technicians, fleet workshops and owner-operators diagnosing an electronic control module warning on ISM CM871 engines use this sheet to verify the fault before parts are replaced.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download.
Related manuals library
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
