Cummins X12 CM2350 X119B (2018 & Newer) Fault Code: 8157 PID: SPN: 521209 FMI: 11/31 Connectivity Module – Condition Exists

Lamp:
None

Reason:
The internal temperature of the connectivity module is above the warning limits.

Effect:
None on performance.

Circuit Description:
The connectivity module is the data logging device. The connectivity module system collects data from the ECM via the vehicle J1939 network.
The connectivity module is also the predictive cruise control system. The predictive cruise control system sends commands to the ECM via the vehicle J1939 network. Predictive cruise control dynamically adjust the vehicle speed profile while the vehicle is operating in cruise control. The vehicle speed profile is optimized for fuel economy based on the upcoming road grade.

Component Location:
The connectivity module in equipped with an internal temperature sensor, which monitors the temperature inside the module during operation. This temperature sensor is internal to the connectivity module and cannot be service separately.

Conditions for Running the Diagnostic:
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 internal temperature of the connectivity module was greater than 105°F [221°C] for more than 5 seconds.

Action Taken When the Fault Code is Active:
1. The ECM logs the fault code immediately when the diagnostic runs and fails.
2. The connectivity module is put into sleep mode.

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 the recommended diagnostic tool or equivalent will change to inactive immediately after the diagnostic runs and passes.
3. The “reset all faults” command in the recommended diagnostic tool or equivalent can be used to clear active and inactive faults, as well as extinguish the MIL for OBD applications.

Shop Talk:
Possible causes of this fault code include:
1. Inadequate air flow to cool connectivity module.
2. Improper mounting of connectivity module.
3. A malfunctioning connectivity module.