Cummins Revision + JDCM850

Jaltest Cummins Revision + JDCM850 — CM850 ECM Insulation Harness

This is the Cummins CM850 ECM insulation harness required to perform the Jaltest Cummins Revision Update (Central Services action) on engines running the CM850 control module. The CM850 was the Cummins electronic control module used primarily in ISX, ISM, ISL, and ISB engines produced during the mid-2000s through approximately 2010. If your shop services pre-emissions or early emissions-era Cummins engines, the JDCM850 harness is what you need on the bench when a Cummins revision is called for.

Jaltest Central Services: Cummins Revision Update

The Jaltest Cummins Revision Update is a Central Services action — a remote, assisted ECM recalibration carried out by Cojali USA's ASE-certified diesel technicians with you connected and the vehicle in the bay. The technician uses Jaltest Diagnostics software to write an updated calibration file directly to the Cummins ECM, addressing factory-released software revisions that can resolve fault codes, improve fuel economy, correct driveability concerns, and restore proper aftertreatment function.

To perform this action, you need two things: an active Jaltest license and the correct insulation harness cable for your specific Cummins ECM family. The cables below are the required harnesses — they provide the proper electrical isolation between the Jaltest interface and the ECM during the programming event, protecting both the ECM and the diagnostic tool.

Central Services Process

• Verify initial conditions in Jaltest Diagnostics software
• Request the Cummins Revision Update through your distributor or Cojali USA directly
• Payment processed (Central Service action: 50)
• Schedule a time — Cojali USA technician connects remotely and carries out the revision
• Your ECM receives the latest factory calibration; faults are cleared

Important: Each cable below includes one FREE Cummins Central Services action as part of the Jaltest Central Services Cables Promotion. The 85 cable price effectively bundles the cable and your first revision action together, making the cable itself nearly cost-neutral for a shop that intends to perform even one Cummins revision.

JDCM850 Cable Specifics

• Compatible ECM family: Cummins CM850 control module
• Applicable engines: Cummins ISX, ISM, ISL, ISB with CM850 ECM (mid-2000s through approximately 2010 production)
• Function: Insulation harness providing proper electrical isolation during Cummins ECM programming events via Jaltest Central Services
• Required for: Jaltest Cummins Revision Update (Central Services action, part number 70810000)
• Includes one free Central Services action — per the Jaltest Central Services Cables Promotion, purchase of this harness includes one complimentary Cummins Revision Update (Detroit Diesel actions excluded from this offer)
• Compatible with Jaltest Link V9 — use with an active Jaltest CV license and the Jaltest Link V9 interface
• Cojali USA part number: 78901064 / JDCM850

Who Needs This Cable

Shops running Jaltest CV that service Cummins-powered commercial vehicles with CM850 control modules. This includes heavy-duty repair shops, fleet maintenance operations, and independent technicians working on Class 6-8 trucks, coaches, and motorhomes with pre-2010 Cummins ISX and ISM engines. If a customer brings in a truck with a Cummins CM850 and you want to perform a factory calibration update — whether to address a fault, update emissions calibration, or restore correct fueling strategy — this is the cable that makes the Central Services process possible.

Why Buy From OEM Diagnostic Tools?

OEM Diagnostic Tools has specialized in professional diagnostic equipment since 2016. We stock the complete Jaltest cable library including all Cummins Central Services harnesses. Free shipping on every order, free tech support at 866-217-0063 from people who understand how the Central Services process works, full warranty, and honest guidance on which Cummins harness matches the ECM in your customer's vehicle.

Call 866-217-0063 for quick answers and help!