0321786 JOHNSON SEAL

Illustration 1 g01068730
While the cruise control On/Off Switch is in the ON position and the vehicle speed is within the range of the programmed "Low Cruise Control Speed Set Limit" and the "High Cruise Control Speed Set Limit", momentarily pressing the set switch will activate the cruise or controlled idle, and the Engine Control Module (ECM) will maintain the current speed.Pressing the resume switch will cause the vehicle speed to ramp to the last cruise control set speed. This assumes that the vehicle speed is above the low cruise control speed set limit for cruise control or the vehicle speed is below the Idle/PTO vehicle speed limit for the idle and the PTO.After a speed has been set, pressing and holding the Set/Resume switch in position will cause the engine to establish a new set speed. The system's reaction depends on the programming of the "Cruise/Idle/PTO Switch Configuration".When the Set/Resume switch is momentarily pressed, the setpoint for the cruise control will change one mph. The rate of change is dependent on the programmed "Idle/PTO Bump RPM" when an idle speed is set.The following background information is related to this procedure:The kickout switch refers to the switch that is used to exit the cruise control, the PTO, or the idle set speed.The operation of the electronic engine cruise control is similar to the operation of the cruise controls that are installed in automobiles. The operation of idle and PTO are similar to the operation of cruise except that the idle and the PTO govern engine rpm instead of vehicle speed.Note: Idle in this procedure is an engine idle rpm above the programmed low idle rpm. Idle is set with the cruise control On/Off switch and the Set/Resume switch. Refer to Troubleshooting, "PTO Switch Circuit - Test" for additional information regarding the programmable options for the dedicated PTO.Service Brake Switch and Clutch SwitchThe service brake switch and the clutch switch are kickout switches. A kickout switch refers to a switch that is used in order to exit the cruise control, the PTO, or the idle set speed. The switches may also be used in order to override the idle shutdown timer. This capability is determined by the customer parameter "Allow Idle Shutdown Override". The service brake switch and the clutch switch are normally closed switches. Depressing the clutch or the brake pedal will open the individual circuit. These switches are OEM supplied. The service brake switch is typically a pressure switch. The clutch switch is typically a limit switch that is mounted near the clutch pedal. The clutch switch is usually adjustable.The "Transmission Style" parameter determines if the clutch switch is used. If the "Transmission Style" parameter is set to "Auto w/o 2 Brk Sw", the clutch switch is ignored. If the "Transmission Style" parameter is set to "Auto w/2 Brk Sw", the clutch switch is replaced with a second service brake switch. If an automatic transmission is used and the "Transmission Style" is set to "Manual", the clutch switch must be replaced with a short circuit from J1/P1-24 to J1/P1-29. This will ensure the proper operation of the cruise control and the engine retarder.The service brake switch connects to vehicle harness connector J1/P1-14. The clutch switch connects to vehicle harness connector J1/P1-24.
Illustration 2 g01068720
Schematic for cruise control switch, service brake switch, and clutch switchTest Step 1. Check the Status of the Cruise Control On/Off Switch
Connect the Caterpillar Electronic Technician (ET) to the data link connector.
Turn the keyswitch to the ON position.
Monitor the status for the "Cruise/Idle On-Off Switch" while the cruise control On/Off switch is cycled.Expected Result:The status for the "Cruise/Idle On-Off Switch" is "On" when the cruise control On/Off switch is in the On position. The status for the "Cruise/Idle On-Off Switch" is "Off" when the cruise control On/Off switch is in the Off position.Results:
OK - The cruise control On/Off switch is working properly. Proceed to Test Step 2.
Not OK - The cruise control On/Off switch is not working properly. Proceed to Test Step 3.Test Step 2. Check the Status of the Set/Resume Switch
Put the cruise control On/Off switch in the On position.
Monitor the status for the "Cruise Control Set/Resume/Accel/Decel Switch J1/P1-25 & 15" while the Set/Resume switch is cycled.Expected Result:The status for the "Cruise Control Set/Resume/Accel/Decel Switch J1/P1-25 & 15" is "Set Switch On" when the Set/Resume switch is in the Set position. The status for the "Cruise Control Set/Resume/Accel/Decel Switch J1/P1-25 & 15" is "Resume Switch On" when the Set/Resume switch is in the Resume position.Results:
OK - The cruise control Set/Resume switch is working properly.STOP
Not OK - The cruise control Set/Resume switch is not working properly. Proceed to Test Step 3.Test Step 3. Determine the Configuration of the Cruise Control Switches
Determine if the wiring for the cruise control switches is wired directly to the ECM or through the J1939 data link.
Verify that the "Cruise Control On/Off Switch" and the "Cruise Control Set/Resume/Accel/Decel Switch" parameters are programmed to reflect the proper wiring.Expected Result:The cruise control switches are wired directly to the ECM.Results:
OK - The cruise control switches are wired directly to the ECM.Repair: Verify that the "Cruise Control On/Off Switch" and the "Cruise Control Set/Resume/Accel/Decel Switch" parameters are programmed correctly. Proceed to Test Step 4.
Not OK - The cruise control switches are wired through the J1939 data link.Repair: Verify that the "Cruise Control On/Off Switch" and the "Cruise Control Set/Resume/Accel/Decel Switch" parameters are programmed to "J1939 - Body Controller", "J1939 - Cab Controller", or "J1939 - Instrument Cluster".Refer to Troubleshooting, "Powertrain Data Link Circuit - Test".STOPTest Step 4. Inspect the Electrical Connectors and the Wiring
Illustration 3 g01068721
Terminal locations at the ECM
Thoroughly inspect the J1/P1 ECM connector, the firewall bulkhead connector and the terminals for the following switches in the connectors:
J1/P1-29 (Sensor Common)
J1/P1-25 & 15 (Set/Resume Switch)
J1/P1-20 (Cruise Control On/Off Switch)Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the switches.Refer to Illustration 3.
Check the allen head screws for each of