PACCAR PX-9 CM2350 (2013-17) Fault Code:3326 PID: SPN:91 FMI:9 SAE J1939 Multiplexed Accelerator Pedal or Lever Sensor System – Abnormal Update Rate

Reason:
SAE J1939 Multiplexed Accelerator Pedal or Lever Sensor System – Abnormal Update Rate. The ECM expected information from a multiplexed accelerator pedal or lever sensor but did not receive it soon enough or did not receive it at all.

Effect:
Engine will only idle.

Circuit Description:
Normally, switches, accelerators, and other components are connected to the engine control module (ECM) directly through individual wires. Multiplexing allows those same components to be hard wired to an original equipment manufacturer (OEM) vehicle electronic control unit (VECU) or transmission electronic control unit (ECU) in the cab. Then component values and states from components such as sensors, accelerators, and switches can be transmitted from the OEM VECU to the Cummins® ECM over the SAE J1939 data link.

Messages sent from OEM VECUs or transmission ECUs are received by the Cummins® ECM and used for controlling the engine. The Cummins® ECM and OEM VECU(s) must be configured properly, so that proper operation of the multiplexed components will occur.

Component Location:
The SAE J1939 data link wiring and the SAE J1939 devices vary by OEM options.

Conditions for Running the Diagnostics:
This diagnostic runs continuously when the keyswitch is in the ON position or when the engine is running.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) did not receive a message from a multiplexed device.

Action Taken When the Fault Code is Active:
The ECM illuminates the red STOP ENGINE lamp and/or the Malfunction Indicator Lamp (MIL) immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code:
1) To validate the repair, perform a key cycle, start the engine and let it idle for 1 minute.
2) The fault code status displayed by INSITE™ electronic service tool will change to INACTIVE immediately after the diagnostic runs and passes.
3) The ECM will turn off the red STOP ENGINE lamp immediately after the diagnostic runs and passes.
4) For On-Board Diagnostics (OBD) engines, the ECM will extinguish the Malfunction Indicator Lamp (MIL) after three consecutive trips where the diagnostic runs and passes.
5) The Reset All Faults command in INSITE™ electronic service tool can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
When this fault code is active, some multiplexed devices may not function as desired. This fault can occur for the following reasons:
1) The ECM is set up properly (components enabled and OEM VECU source addressed correctly) to receive information from an OEM VECU, but the OEM VECU is actually transmitting a message that says that component is not available for multiplexing. This can be caused when a multiplexed component is enabled in the Cummins® ECM, but the OEM VECU source address of the VECU transmitting the component message is incorrect in the Cummins® ECM, or the OEM VECU is not set up to transmit the multiplexed component message.
2) This fault can also be caused by a damaged J1939 data link connection between the OEM VECU and Cummins® ECM, a damaged connection between the component and the OEM VECU, damaged OEM VECU, or damaged Cummins® ECM. It may be necessary to contact the OEM for proper multiplexing configuration. It is possible to use INSITE™ electronic service tool to monitor multiplexed components. Reference the appropriate OEM wiring diagram when troubleshooting circuits that utilize wiring supplied by the OEM.

Possible Causes:
1) Inactive fault codes
2) Faulty OEM VECU
3) Faulty ECM
4) Faulty service data link harness