Cummins ISM code 123 is the DiagTechPro reference page for this Cummins diagnostic fault code 123 document, a 8-page PDF sourced from TruckFaultCodes.com (Copyright 2017) that covers the intake manifold pressure sensor circuit. The intake manifold pressure/temperature sensor monitors intake manifold pressure and passes information to the electronic control module (ECM) through the engine harness. If intake manifold pressure becomes too high, it will cause a derate condition. When the condition is detected the ECM logs the fault and turns on the yellow warning lamp to alert the driver and technician.
Cummins ISM code 123 document details
| Brand | Cummins |
|---|---|
| Model coverage | ISM CM570 (1999-02) / DTCs; ISX CM570 (1999-02) / DTCs; Signature CM570 (1999-02) / DTCs |
| System / Group | ISM CM570 (1999-02) / DTCs |
| Fault identifier | Code 123 (PID P102, SPN 102, FMI 4) |
| Warning lamp | Yellow |
| Source | TruckFaultCodes.com |
| Year / Revision | Copyright 2017 |
| Pages | 8 |
| File size | 0.4 MB |
| Format | |
| Language | English |
Document table of contents
- Circuit Description
- Component Location
- Shop Talk
- Troubleshooting Steps
- Repair verification and clearing fault codes
Applicable truck models
This document applies to Cummins ISM CM570 (1999-02) / DTCs; ISX CM570 (1999-02) / DTCs; Signature CM570 (1999-02) / DTCs electronic engines used in on-highway and vocational trucks. The intake manifold pressure/temperature sensor is located in the intake air manifold toward the front of the engine. The troubleshooting section walks through connector and pin inspection, engine-harness resistance measurements and pin-to-pin continuity checks, and ends with a road test that confirms the code is inactive and all fault codes are cleared. Because the same procedure isolates the sensor, the harness and the ECM in turn, it prevents replacing parts that are still good. Verify engine calibration and coverage against the official Cummins engine support site before ordering parts.
Who needs this Cummins ISM code 123 manual
Any mechanic or workshop owner diagnosing ISM code 123 needs this PDF to follow the factory circuit and resistance checks in the correct order. Check for high restriction in the intake air manifold due to a shutdown device in the manifold if the vehicle is equipped with a shutdown device. Do not remove this device. If the engine is operated in a flammable atmosphere, the device is an essential safety feature.
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