Cummins X15 CM2450 X124B (2018 & Newer) Fault Code: 3494 PID: SPN: 1081 FMI: 7/7 Engine Wait to Start Lamp – Mechanical System Not Responding or Out of Adjustment

Lamp:
Amber

Reason:
Engine wait to start lamp – mechanical system not responding or out of adjustment. Wait to start lamp has malfunction.

Effect:
None on performance.

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 OEM ECM over the SAE J1939 data link. Messages sent from OEM VECUs or transmission ECUs are received by the OEM ECM and used for controlling the engine. The OEM 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 at initial key ON when the intake air heater is commanded ON.

Conditions for Setting the Fault Codes:
The Engine Control Module (ECM) detected a malfunction of the wait to start lamp.

Action Taken When the Fault Code is Active:
The ECM illuminates the amber check 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, and leave the key in the ON position for 1 minute.
2. The fault code status displayed by the diagnostic tool will change to inactive immediately after the diagnostic runs and passes.
3. The ECM will turn off the amber check engine lamp immediately after the diagnostic runs and passes.
4. The reset all faults command in the diagnostic tool 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. A malfunctioning wait to start lamp.
2. A short circuit to ground in the OEM harness.
3. An open circuit in the OEM harness.