The ISB and ISC ECM failures we see most

These modules live on the engine and take heat and vibration for a living. Most of what fails is repairable.

Injector driver failure: dead cylinder or injector circuit codes

What you see: A miss, a dead hole, or injector open/short codes that stay after a new injector.

What's happening: The driver stage inside the ECM has failed.

What we do: We rebuild the driver circuit and bench-fire every injector channel with a real load.

No communication with INSITE

What you see: No tool will connect on J1939 or J1708. Cannot read codes, cannot program.

What's happening: The datalink transceiver or its supply has failed.

What we do: We restore the datalink on the bench and verify with INSITE.

No power-up after a jump or battery swap

What you see: Dead key-on, no ECM power, sometimes after welding or a reverse-polarity jump.

What's happening: Overvoltage took out the internal supply or protection components.

What we do: We repair the supply section and load-test the module.

Heat-related stall or intermittent codes

What you see: Runs cold, quits hot, or codes that come and go with engine temperature.

What's happening: Cracked solder joints or a failing regulator from years of engine-mounted heat cycling.

What we do: We reflow and repair the failed section and thermal-cycle the module on the bench.

Don't see your exact symptom? Send it in anyway. We bench-test every unit before we tell you what's going on, and if we fix it the diagnostic cost you nothing.

ISB, ISC and ISL ECM families we repair

The ECM part number is on the module label.

ECM familyEnginesOur bench
CM550 / CM554ISB, ISC, ISL (1998-2002)about 5 days
CM850ISB, ISC, QSB (2003-2007)about 5 days
CM2150ISB, ISC, ISL (2007-2010)about 5 days
CM2250 / CM2350ISB6.7, ISL9, ISX12 (2010+)about 5 days

How the repair goes

  1. 1

    Ship it in

    Self-ship free, or add a prepaid UPS label. Drop-offs in Princeton, MN by appointment. Include your engine serial number.

  2. 2

    We test it

    $350 bench fee, credited toward the repair. We tell you exactly what failed, usually within a day of receipt.

  3. 3

    We fix it

    Injector driver repair, power and communication restoration, board-level reflow, connector pin repair, whatever it needs. About 5 days on the bench.

  4. 4

    Back to you

    Programmed to your engine, every channel bench-tested, 2-year warranty. Status email at receipt, at diagnosis, and at ship.

ISB exchange units we stock

If yours is beyond repair, or the truck can't wait: remanufactured, bench-tested, programmed to your engine serial, 2-year warranty. Usually ships the same day.

Questions we get on ISB ECMs

How much does a Cummins ISB ECM repair cost?

$675 flat, bench fee included. The $350 bench-test fee credits 100% to the repair. Dodge Ram pickup ECMs are priced separately at $545.

How long does an ISB or ISC ECM repair take?

About 5 days on the bench plus 1-3 days return shipping.

Will I keep my calibration?

Yes. We preserve the calibration and parameters and program the module back to your engine serial before it ships.

Do you stock ISB exchange units?

Yes, tested CM550, CM850, CM2150 and CM2350 units with a 2-year warranty, for trucks that cannot wait or modules beyond repair.

Related: All Cummins ECM repair · ISX / ISM ECM repair · Dodge Ram Cummins ECM repair · Komatsu (Cummins-based) ECM

Verified Google reviews

What truck owners & shops say

★★★★★
"Mike does great work and sent my repaired ECM back to me right away. Saved me thousands of dollars vs. using the dealer. Would recommend to anyone that needs prompt repair."
Michael B. via Google
★★★★★
"From ECMs and harnesses to straight-out cutting counter bores in-frame for us. Great shop — and a great person to have in your pocket."
Mega24v via Google
★★★★★
"Highly recommend these guys! Fast turnaround — I had my ECM back and repaired by the next day. Will definitely do more business in the near future."
Javon Z. via Google
★★★★★
"Michael is a diesel guru. He made my rig scream and had it done when he said, for the price we agreed to. I'd highly recommend him."
Glenn S. via Google
★★★★★
"Mike is highly knowledgeable in all areas of diesel repair — from mechanical work to advanced electrical diagnostics. You can count on him to get the job done right."
David F. via Google
★★★★★
"Mike is a very professional and skilled mechanic. I highly recommend him for any of your needs."
Justin N. via Google

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