The Cummins ISX code 3737 manual is a 6-page PDF that documents fault code 3737, the engine starter mode overcrank protection condition fault. It explains that overcrank protection, or starter lockout, prevents starter-motor damage by locking out the starter after excessive cranking until the motor has cooled. The procedure is credited to TruckFaultCodes.com and covers the circuit description, component location and full troubleshooting steps.
Official document details
| Brand | Cummins |
| Model coverage | Cummins ISX11.9 CM2250 and ISX12 CM2250 (2010-12) engines |
| System / group | ISX11.9 CM2250 (2010-12) / DTCs |
| Fault code | 3737 (PID S115, SPN 1675, FMI 31) |
| Warning lamp | None |
| Pages | 6 |
| File size | 0.2 MB |
| Format | |
| Language | English |
Document table of contents
- Fault code 3737 description
- Circuit description and ECM operation
- Component location
- Shop talk and possible causes
- Step-by-step troubleshooting flow
Applicable truck models
This diagnostic applies to Cummins ISX11.9 CM2250 and ISX12 CM2250 (2010-12) engines. The overcrank protection feature is controlled entirely by the ECM and cannot be modified. This is a no-lamp fault; while active, the starter is locked out and the engine cannot be cranked until the starter motor has adequately cooled. For engine data and authorised service, visit the Cummins official website.
Who needs this Cummins ISX code 3737 manual
Heavy-duty diesel technicians, fleet workshops and owner-operators reach for this manual when fault code 3737 is logged as an information event. It helps a technician confirm that a no-crank complaint after repeated start attempts is normal starter-protection behaviour rather than a starter or circuit fault.
Download the ISX code 3737 PDF
The complete procedure, wiring detail and step tables are available in the DiagTechPro manuals library; a free account is required to download the PDF. Keep it alongside the related ISX11.9 CM2250 fault-code sheets listed below.
Related manuals library
