Cummins M11 code 145 is the Cummins M11 CELECT Plus diagnostic entry for fault code 145, coolant temperature sensor circuit (SPN 110, FMI 4). This page summarises what the code reports, the circuit involved, and the official Cummins troubleshooting document behind it, taken from the fault-code publication for Cummins M11 CELECT Plus engines. It is written for mechanics and workshop owners who want to confirm the code before ordering parts.
What Cummins M11 code 145 means
Fault code 145 is logged against coolant temperature sensor circuit. The document reports a warning lamp, which tells the driver to have the engine serviced soon. The coolant temperature sensor is used by the ECM to monitor the temperature of the engine coolant. The coolant temperature is used by the ECM for the engine protection system, timing, and fueling control.
Circuit description and component location
Component location. M11 – The coolant temperature sensor is located in the front of the thermostat housing support on most applications. On bus applications, the coolant temperature sensor is usually located at the rear of the thermostat housing support. N14 – The coolant temperature sensor is located on the top of the thermostat housing.
The official diagnostic identifiers for this fault let you match the code across scan tools and repair records:
- PID: P110
- SPN: 110
- FMI: 4
- Lamp: YELLOW
- SRT code: 00-089
The document walks the technician through the numbered troubleshooting steps for this circuit, from connector inspection to resistance and short-to-ground measurements, so the fault can be confirmed before any part is replaced. Each step ends in a yes or no branch that either clears the code or sends you to the next check, which keeps the diagnosis systematic and avoids guesswork on the bench.
How to diagnose Cummins M11 code 145
Start by reading the live codes with an approved Cummins diagnostic tool and confirming the code is active. Inspect the harness connector pins for bent or corroded terminals, pushed-back pins and moisture, then follow the manufacturer resistance and continuity checks in the order given. Diagnostic procedures for Cummins M11 CELECT Plus engines are published by Cummins; see the Cummins official website for engine documentation and authorised service-network support.
Official references and part numbers
Standard Repair Time reference SRT 00-089; Cummins Troubleshooting and Repair Manual, Bulletin 3666130; service tool part numbers such as 3823548, 3824437, 3824638. Use these identifiers to order the correct Cummins service publication and tooling, and to log the repair accurately for the fleet record. The full PDF is filed in the DiagTechPro manuals library for mechanics and workshop owners to download.
Applies to these truck models
This is the manufacturer document shared across 2 model families. It applies to:
- Cummins DTCs
- Cummins M11 CELECT Plus (1995-98)
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