Cummins ISB4.5 CM2150 Fault Code: 3226 PID: SPN: 91 FMI: 9 SAE J1939 Multiplexed Accelerator Pedal or Lever Sensor System – Abnormal Update Rate.

Circuit Description
Normally, switches, accelerators, and other components are connected to the engine ECM directly through individual wires. Multiplexing allows those same components to be hard wired to an 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® engine ECM over the SAE J1939 data link.

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

Component Location
The J1939 data link wiring and VECU location varies by OEM. Refer to the OEM service manual.

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

Conditions for Setting the Fault Codes
The ECM does not receive a valid J1939 message from the multiplexed accelerator pedal or lever sensor for more than 1 second.

Action Taken When the Fault Code is Active
-The ECM illuminates the red STOP ENGINE light immediately when the diagnostic runs and fails.

Conditions for Clearing the Fault Code
-To validate the repair, start the engine and let it idle for 1 minute.
-The ECM will turn off the red STOP ENGINE light immediately after the diagnostic runs and passes.
-This fault code can also be cleared with INSITE™ electronic service tool.

Shop Talk
When this fault code is active, some multiplexed devices may not function as desired.

This fault can occur for the following reasons:
-When 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.
-This fault can also be caused by a malfunctioning J1939 data link connection between the OEM VECU and Cummins® ECM, a malfunctioning connection between the component and the OEM VECU, bad OEM VECU or malfunctioning 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.