Cummins ISM Code 155 documents the Intake Manifold Air Temperature High diagnostic and troubleshooting procedure for the Cummins ISM CM570 (1999-02) engine platform. This 2-page fault code sheet from TruckFaultCodes.com (Copyright 2017) covers fault code 155 (PID P105, SPN 105, FMI 0/0, RED lamp) and the checks used to confirm and clear it.
Official document details
| Brand | Cummins |
|---|---|
| Model coverage | ISM CM570, ISX CM570, Signature CM570 (1999-02) |
| System / Group | Diagnostic Trouble Codes (DTCs) |
| Fault code | 155 — PID P105, SPN 105, FMI 0/0 |
| Warning lamp | RED |
| Pages | 2 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Circuit description
- Component location
- Shop talk
- Troubleshooting steps
- Fault code verification and clearing
Cummins ISM Code 155 diagnostic steps
This fault reports that intake manifold air temperature has exceeded the maximum engine-protection limit. The variable-resistor sensor sits in the air intake manifold and is fed 5 volts by the ECM. Possible causes include restricted airflow through the charge air cooler and an undersized charge air cooler. Technicians verify the ECM calibration, inspect the charge-air system, and confirm the reading before the engine-protection event is cleared with a diagnostic tool.
Applicable truck models
This sheet applies to Cummins ISM CM570, ISX CM570, and Signature CM570 (1999-02) engines built around the CM570 ECM and the intake manifold air temperature. The intake manifold air temperature sensor is in the air intake manifold. The document is laid out with a circuit description, a component location note, shop-talk tips, and a step-by-step troubleshooting chart whose go-to branches route the technician through each measurement. Refer to the official Cummins engine support site for wiring diagrams and component part numbers.
Who needs this Cummins ISM Code 155 manual
Heavy-duty diesel technicians, fleet service teams, and owner-operators diagnosing a red-lamp intake manifold air temperature fault will use this sheet to follow the factory decision tree, confirm the reading, and repair the harness, connector, or component instead of replacing parts on guesswork. It spells out each measurement threshold and its pass or fail branch, so the fault can be verified active, the repair validated, and the inactive code cleared with the diagnostic tool.
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