Volvo VNL D13 - Intermittent SPN 249 FMI 9 Data Link Issues

Question

My 2018 VNL started throwing an SPN 249 FMI 9 code while hauling over the Grapevine. The dash is showing a 'Transmission Service' warning and sometimes the engine starts derating after a hard pull. It feels like the ECU is losing track of fuel/air parameters or getting garbage data from the network.

torque_terry · Accepted Answer

Found the issue after pulling the floor mat. The main J1939 harness connector under the steering column had three pins that were pushed back and corroded from road salt tracked in during the winter. I replaced the connector shell (Part #20396637) and repinned the wires with new terminals. Resistance back to a steady 61.2 ohms and the SPN 249 fault has not returned in over 5,000 miles of driving.

Ashley Park · Answer

I had this on a Mack which is basically the same setup. It turned out to be the terminating resistor on the end of the rail. If the resistor gets moisture in it, the whole CAN bus goes haywire and starts throwing those 249 codes.

Chris Donovan · Answer

Check the wiring harness near the pass-through on the firewall. The D13 vibration tends to rub the green and yellow twisted pairs against the bracket, which causes intermittent shorts to ground.

turbo_tony · Answer

When you see SPN 249 combined with 639, you are looking at a Backbone J1939-1 issue. Check your resistance at the diagnostic port between pins C and D; you should see 60 ohms with the batteries disconnected.

Volvo VNL D13 - Intermittent SPN 249 FMI 9 Data Link Issues

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