ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – Engine Brake Does Not Operate

Symptom Tree  t036

This is symptom tree t036
Cause Correction

Engine brake on/off switch is off

Turn on the switch.

 

Programmable parameters or selected features are not correct

Check the programmable parameters and the selected features with an electronic service tool. Set the parameters and features again if necessary. Refer to Section 1 of the Operation and Maintenance Manual, ISC, ISCe, and ISL Engines, Bulletin 4021428 or the Operation and Maintenance Manual, QSC8.3 and QSL9 Engines, Bulletin 4021518.

 

Electronic fault codes active or high counts of inactive fault codes

Refer to Section TF in the Troubleshooting and Repair Manual, CM850 Electronic Control System, ISC and ISL Engines, Bulletin 4021416, or Troubleshooting and Repair Manual, Electronic Control System, ISC, QSC8.3, and QSL Engines, Bulletin 3666271 for fault code troubleshooting.

 

Engine brake on/off switch or circuit is malfunctioning

Check the engine brake on/off switch and circuit. Refer to Procedures 020-012, 020-015, or Procedures 019-034 and 019-035 in the Troubleshooting and Repair Manual, CM850 Electronic Control System, ISC and ISL Engines, Bulletin 4021416, or Procedures 019-034 and 019-035 in Troubleshooting and Repair Manual, Electronic Control System, ISC, QSC8.3 and ISL Engines, Bulletin 3666271.

 

Engine brake harness connectors are loose or broken

Check the engine brake harness connectors. Check the engine brake harness for continuity.

 

Clutch switch or circuit is malfunctioning

Check the clutch switch adjustment, switch, and circuit. Refer to Procedures 019-009 and 019-010 in the Troubleshooting and Repair Manual, CM850 Electronic Control System, ISC and ISL Engines, Bulletin 4021416, or Procedure 019-009 in Troubleshooting and Repair Manual, Electronic Control System, ISC, QSC8.3 and ISL Engines, Bulletin 3666271.

 

Accelerator pedal or lever position sensor or circuit is malfunctioning

Check for foot pedal restriction. Check the accelerator pedal or lever position sensor and circuit. Refer to Procedures 019-085 and 019-086 in Troubleshooting and Repair Manual, CM850 Electronic Control System, ISC and ISL Engines, Bulletin 4021416, or Procedures 019-085 and 019-086 in Troubleshooting and Repair Manual, Electronic Control System, ISC, QSC8.3 and ISL Engines, Bulletin 3666271.

 

Service brake pressure switch or circuit is malfunctioning

Check the service brake pressure switch and circuit. Refer to the OEM service manual.

 

Engine electrical ground is malfunctioning

Check engine ground to chassis and chassis ground to battery negative (-) post. Refer to the OEM service manual and Procedure 013-009.

 

Lubricating oil leak (internal)

Check the engine brake control valve and the engine brake piston. Refer to Procedures 020-004.

 

Engine brake lubricating oil passage is restricted

Check the engine brake assembly for restriction. Refer to Procedure 020-004.

 

Engine brake adjustment is not correct

Adjust the engine brakes. Refer to Procedure 020-004.

 
Last Modified:  29-Jul-2005