The Cummins ISM code 398 manual is a 5-page diagnostic PDF for the actuator circuit on the ISM CM570 (1999–2002) engine. It covers the rear timing actuator that the electronic control module (ECM) pulses to control fuel metering on the fuel delivery housing.
Cummins ISM code 398 document details
| Brand | Cummins |
| Model coverage | ISM CM570 (1999–2002) |
| System / group | Actuator circuit — DTCs |
| DTC number | 398 |
| PID / SPN | S084 / 1245 |
| FMI | 5/5 |
| Warning lamp | YELLOW |
| Pages | 5 |
| File format | |
| Language | English |
Document table of contents
- Circuit description and component location
- Shop talk on open-circuit failure modes
- Actuator harness pin inspection
- Actuator resistance measurement
Applicable truck models
This procedure applies to the ISM CM570 (1999–2002) engine and the shared CM570 fuel-system platform found in on-highway trucks. The same fault-code logic is carried across related CM570 engine families of that era. For engine identification and factory service references, see the manufacturer at the Cummins official website.
Who needs this Cummins ISM code 398 manual
The document explains that each timing actuator connects to the ECM through a supply and a return wire and that the normally closed solenoid opens only on an electrical pulse. It locates the rear timing actuator as the third actuator from the front of the engine. For this fault the listed failure modes are an open circuit, a short circuit to ground, high actuator resistance, and loss of boost voltage inside the ECM. The steps inspect the actuator harness connector pins before measuring resistance.
This guide suits diesel technicians and workshop owners who face a rear timing actuator open-circuit or high-resistance fault and want the ordered pin and resistance checks. It reads as fault code 398 troubleshooting steps for the actuator circuit, so the ECM circuit diagnosis stays ordered and evidence-based rather than a parts-swap guess, and it maps cleanly onto a scan-tool session on the CM570 engine platform.
The full PDF is available in the DiagTechPro manuals library, where 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
