CM870 and ISX Engines – FAULT CODE 2366

Engine Brake Solenoid Number 1 Signal Circuit

Overview

CODE	REASON	EFFECT
Fault Code: 2366 PID: S28 SPN: 1072 FMI: 3/3 LAMP: Amber SRT:	Engine Brake Actuator Circuit Number 1 – shorted high. Open circuit or high voltage detected at the engine brake solenoid number 1 signal circuit.	Engine brake on cylinder number 1 can be on all the time, or can not be activated.

Engine Brake Solenoid Signal Circuit SMALL | MEDIUM | LARGE

Circuit Description

The electronic control module (ECM) controls the engine brakes on cylinder number 1 by sending a signal on engine brake solenoid number 1 signal circuit. The ECM will only command the brakes ON under certain operating conditions.

The engine brake fault code will only become active once the engine brakes are activated and will remain active until the ECM is powered down. Once the ECM is powered down, the fault code will be inactive until the engine brakes are activated again if the circuit interruption is still present. This tree is designed to troubleshoot an inactive fault code.

Component Location

The engine brake solenoids are located under the valve cover. The engine brake connector is located on the intake side of the cylinder head above and forward of the air inlet horn.

Shop Talk

Possible causes of this fault include:

• Open circuit in the engine harness, brake harness, or engine brake solenoids
• Signal circuit shorted to voltage source in the engine harness
• Incorrect ECM calibration code in the ECM
• Damaged ECM
• Loose connection at the engine brake solenoid.

Refer to Troubleshooting Fault Code t05-2366v2