Electronic Calibration Code Incompatibility
The CUMMINS-342 (Cummins) diesel fault code means: Electronic Calibration Code Incompatibility. This is a moderate severity code.
Unverified. We could not confirm this code's definition against freely available manufacturer documentation, so treat the meaning, severity and fix guidance on this page as unconfirmed. Check it against the manufacturer's service information for your exact model and serial range before acting on it. This page is kept out of search engines for that reason, and we are working through this family manual by manual.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- advanced
- Estimated cost
- $250-$800
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View pilot availability →What Are the Symptoms of CUMMINS-342?
- Check Engine Light illuminated
- Engine may shut down or fail to start
- Erratic engine behavior or warning messages on dash
- Loss of communication with scan tool
- Engine derate or limp mode
What Causes CUMMINS-342? (Most Likely First)
- Internal ECM processor or memory fault Very Likely
- ECM software corruption requiring reflash Likely
- Low battery voltage during ECM power-up Possible
- Damaged ECM connector or harness pins Possible
- Ground fault at ECM mounting location Less Likely
Can I Still Drive with CUMMINS-342?
Yes, but fix soon. CUMMINS-342 is rated moderate severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What is Cummins fault code 342?
Cummins fault code 342 indicates: Electronic Calibration Code Incompatibility. It is a moderate-severity fault in the engine control module or its circuits.
Can I drive with Cummins fault code 342?
Yes, short-term driving is typically safe with fault 342, but the fault will illuminate the Check Engine Light and must be diagnosed soon. Monitor for power loss, unusual noises, or gauge changes and pull over if conditions worsen.
How much does it cost to fix Cummins fault 342?
Repair cost is approximately $250-$800 including parts, labor, and any dealer programming required. DIY repairs (sensor replacement) fall at the low end; pump, aftertreatment, or ECM work falls at the high end and usually requires INSITE diagnostic software.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose CUMMINS-342?
Connect Cummins INSITE or Nexiq USB-Link and confirm fault code 342 (SPN 630 FMI 13) is active, not historical.
Measure ECM battery supply voltage at pins - must read battery voltage key-on and stable during cranking (no drops below 9V).
Inspect ECM grounds at frame and engine block for clean, tight connections with no paint or corrosion.
Check for available Cummins calibration updates via INSITE. Reflash if an update addresses this fault.
Perform ECM output driver and internal test via INSITE. If it fails, ECM replacement and dealer programming is the fix.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)
Which Vehicles Commonly Get CUMMINS-342?
- Peterbilt 579, 567 with Cummins ISX/X15
- Kenworth T680, T880 with Cummins X15
- Ram 2500/3500 with 6.7L Cummins
- Ram 4500/5500 with 6.7L Cummins
- Freightliner M2 106 with Cummins ISL9/L9
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