Circuit Description
The electronic control module (ECM) enables the exhaust brake by sending a signal to the
relay that controls the exhaust brake under certain conditions.
Component Location
Refer to the original equipment manufacturer’s (OEM) diagram for the location of the engine brake.
Cummins ISB CM550 (1990-94) Fault Code: 242 PID: 84 SPN: 84 FMI: 10 Vehicle Speed Sensor (VSS Circuit
Cummins ISB CM550 (1990-94) Fault Code: 241 PID: 84 SPN: 84 FMI: 2 Vehicle Speed Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 235 PID: 111 SPN: 111 FMI: 1 Engine Coolant Level – Engine Protection
Cummins ISB CM550 (1990-94) Fault Code: 234 PID: 190 SPN: 190 FMI: 0 Engine Overspeed Circuit
Cummins ISB CM550 (1990-94) Fault Code: 222 PID: 108 SPN: 108 FMI: 4 Ambient Air Pressure Sensor Circuit
Cummins ISB CM550 (1990-94) Fault Code: 221 PID: 108 SPN: 108 FMI: 3 Ambient Air Pressue Sensor Circuit
