Cummins ISX11.9 code 1938 is the diagnostic fault code for the ECU power output supply voltage 1 reading below the normal range, and this page describes the official Cummins troubleshooting document for it. This fault is reported as SPN 3597 / FMI 18, and PID S212. The 13-page PDF gives the circuit description, the conditions that set fault code 1938, the action taken when it is active, and the guided troubleshooting steps needed to confirm and repair it.
Official document details
| Brand | Cummins |
|---|---|
| Model coverage | ISX11.9 CM2250 (2010-12), ISX12 CM2250 (2010-12) |
| System / Group | DTCs — Fault Code 1938 |
| SPN / FMI | 3597 / 18 |
| PID | S212 |
| Warning lamp | Amber |
| Pages | 13 |
| File size | 0.3 MB |
| Format | |
| Language | English |
Document table of contents
- Overview and circuit description
- Fault code 1938 — reason, cause and effect
- Conditions for running the diagnostics
- Conditions for setting the fault code
- Action taken when the fault code is active
- Conditions for clearing the fault code
- Shop Talk — possible causes
- Associated procedures and guided troubleshooting steps
Cummins ISX11.9 code 1938 coverage
The variable geometry turbocharger is activated by the VGT actuator, a smart device that receives commands over the J1939 data link, runs its own diagnostics, and reports malfunctions back to the ECM. The procedure covers ISX11.9 CM2250 (2010-12) and ISX12 CM2250 (2010-12) engines and is shared across the CM2250 engine family listed in the associated procedures table. Cummins publishes the full specifications and service procedures for this engine family; see the manufacturer at Cummins.
The document lists the possible causes the factory tree checks:
- low supply voltage reported on the ECU power output circuit
- a wiring or connector fault at the VGT actuator power supply
- a malfunctioning VGT actuator or power supply circuit
Who needs this Cummins ISX11.9 code 1938 manual
Fleet technicians and workshop owners will use this guide to read the amber-lamp fault with the INSITE electronic service tool, inspect the VGT actuator power supply and its wiring, and decide whether the sensor, harness, or ECM is at fault. Confirm Cummins ISX11.9 code 1938 against live data before replacing any part, and follow the guided troubleshooting steps in the order the document gives them.
The full PDF is available in the DiagTechPro manuals library; a free account is required to download it.
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
