If the columns are missing during self test then return for repair.[support@jpitech.com for RMA number]

Otherwise:

• Swap the ‘faulty’ probes wire to the next cylinders ‘good’ probe.  Now since that ‘good’ probes wire is now off, fasten it to the ‘faulty’ probe. You just swap the wire, not the probes. Now turn on the EDM and get up to operating temperature. Does the other ‘good’ EDM cylinder channel now behave in the same way?  Then it’s the probe. If not and the original ‘faulty’ cylinder is still behaving in the same way, (no change)-  then it could be a bad crimp or connection or instrument is faulty.
• Check that the EDM is grounded at the engine (not in the instrument panel).
• Check for a bent or recessed pin on the rear P2 connector.
• Check crimps between probe and harness.
• Check that leads are not shorted together on the harness or where the probes connect to the harness.