System Operation Description:
Use this procedure under the following situation:
The clutch pedal position switch is suspected of preventing normal operation of cruise control, idle
set speed, or PTO operation.
The following switch circuits can also prevent the correct operation of the cruise control, idle set speed or PTO operation:
• Service Brake Pedal Position (Switch 1)
• Service Brake Pedal Position (Switch 2)
• Neutral Switch
• Cruise Control Set/Resume Switch
• Cruise Control On/Off Switch
• PTO On/Off Switch
The switches are described in the respective circuit tests in Troubleshooting.
All of the following customer programmable parameters can affect cruise control, idle set speed, and PTO operation:
• “Low Cruise Control Speed Set Limit”
• “High Cruise Control Speed Set Limit”
• “Idle Vehicle Speed Limit”
• “Cruise/Idle/PTO Switch Configuration”
• “Idle/PTO Bump rpm”
• “Idle/PTO rpm Ramp Rate”
• “PTO Vehicle Speed Limit”
The vehicle speed calibration can also affect the cruise control, the idle set speed, and the PTO if the vehicle speed calibration is incorrectly programmed. Refer to Troubleshooting, “Customer Specified Parameters”.
Clutch Switch
The clutch pedal position switch is normally closed when the pedal is released. Depressing the clutch pedal should open the circuit. This switch is OEM supplied. The clutch pedal position switch is typically a limit switch that is mounted near the pedal. The clutch pedal position switch is usually adjustable.
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 Caterpillar 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 by using 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.
Usage of Transmission Style Switches
The “Transmission Style” parameter determines the switches that will be used. The following switches can be used with being dependent on the parameter setting:
• Clutch Pedal Position
• Neutral
• Service Brake Pedal Position (Switch 1)
• Service Brake Pedal Position (Switch 2)
Refer to Table 2 for additional information.
If the “Transmission Style” parameter is programmed to one of the following options, the input for the
clutch pedal position switch is not used:
• Automatic Option 1
• Automatic Option 2
• Automatic Option 3
• Automatic Option 4
A Service Brake Pedal Position (Switch 1) is required for all configurations. The Service Brake Pedal Position (Switch 1) connects to the ECM through connector P1:45. The Service Brake Pedal Position (Switch 2) connects to the ECM through connector P1:64. The clutch pedal position switch connects to the ECM through connector P1:22. The neutral switch connects to the ECM through Connector P1:62.
Test Step 1. Check the Status for the “Clutch Pedal Position Switch”
A. Connect the electronic service tool to the data link connector.
B. Turn the key switch to the ON position.
C. Check the status of the “Clutch Pedal Position Switch”.
D. Depress the clutch.
E. Check the status of the “Clutch Pedal Position Switch”.
Expected Result:
The status for the “Clutch Pedal Position Switch” is “Off” when the clutch is released. The status for the “Clutch Pedal Position Switch” is “On” when the clutch is depressed.
Results:
• OK – The clutch pedal position switch is operating correctly. STOP.
• Not OK – The clutch pedal position switch is not operating correctly. Proceed to Test Step 2.
Test Step 2. Determine the Configuration of the Clutch Pedal Position Switch
A. Determine if the wiring for the clutch pedal position switch is wired directly to the ECM or through the J1939 data link.
Note: J1/P1:22 can only be used for the clutch pedal position switch. If the clutch pedal position switch is wired to J1/P1:22, the clutch pedal position switch is wired directly to the ECM.
B. Verify that the “Clutch Pedal Position Switch” parameter is programmed to reflect the proper wiring.
Expected Result:
The clutch pedal position switch is wired directly to the ECM.
Results:
• OK – The clutch pedal position switch is wired directly to the ECM.
Repair: Verify that the “Clutch Pedal Position Switch” parameter is programmed to “J1/P1:22”.
Proceed to Test Step 3.
• Not OK – The clutch pedal position switch uses the J1939 data link.
Repair: Verify that the “Clutch Pedal Position Switch” parameter is programmed “J1939 – Body Controller”, “J1939 – Cab Controller”, or “J1939 – Instrument Cluster”.
Refer to Troubleshooting, “Powertrain Data Link Circuit – Test”.
STOP.
Test Step 3. Inspect Electrical Connectors and Wiring
A. Thoroughly inspect the J1/P1 ECM connector, the firewall bulkhead connector and the terminals
for the following switches in the connectors:
• J1/P1:22 (Clutch Pedal Position Switch)
• J1/P1:5 (AP Sensor/Switch Sensor Common)
Refer to Troubleshooting, “Electrical Connectors – Inspect” for details.
B. 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 55.
C. Check the ECM connector (Allen Head Screw) for the proper torque of 6.0 N·m (55 lb in).
D. Check the harness and wiring for abrasion and pinch points from the sensor to the ECM.
Expected Result:
All connectors, pins and sockets should be completely coupled and/or inserted and the harness and wiring should be free of corrosion, abrasion or pinch points.
Results:
• OK – Proceed to Test Step 4.
• Not OK
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.
Verify that the repair eliminates the problem.
STOP.
Test Step 4. Check the Switch Circuit
A. Turn the key switch to the Off position.
B. Fabricate a jumper wire 100 mm (4 inch) long.
Crimp a Deutsch pin to both ends of the wires.
C. Disconnect the P1 ECM connector.
D. Connect a 140-2266 Cable (Seventy-Pin Breakout) between the J1 and P1 ECM connectors.
E. Install the jumper into terminal 22 (Clutch Pedal Position Switch) of the breakout T. Connect the other end of the jumper to terminal 5 (AP Sensor/Switch Sensor Common) of the breakout T.
F. Turn the key switch to the On position.
G. Connect the electronic service tool to the data link connector.
H. Access the status for the “Clutch Pedal Position Switch” on the electronic service tool.
I. While the status for the “Clutch Pedal Position Switch” is being monitored on the electronic service tool, remove the jumper from terminal 5 (AP Sensor/Switch Sensor Common). Insert the jumper into terminal 5 (AP Sensor/Switch Sensor Common).
Expected Result:
When the jumper wire is installed, the status for the “Clutch Pedal Position Switch” is “Off”. When the jumper wire is removed, the status for the “Clutch Pedal Position Switch” is “On”.
Results:
• OK – The ECM is functioning properly.
Repair: Remove the breakout T and reconnect the P1 ECM connector to the ECM.
Proceed to Test Step 5.
• Not OK – The ECM is not functioning properly.
Repair: Perform the following repair:
1. Temporarily connect a test ECM.
2. Remove the breakout T and reconnect the P1 ECM connector to the ECM.
3. If the problem is resolved with the test ECM, reconnect the suspect ECM.
4. If the problem returns with the suspect ECM, replace the ECM.
5. Verify that the repair eliminates the problem.
STOP.
Test Step 5. Insert a Jumper at the Clutch Switch
A. Turn the key switch to the Off position.
B. Find the clutch switch in the vehicle.
C. Disconnect the wires from the clutch switch terminals.
D. Turn the key switch to the On position.
E. Connect the electronic service tool to the data link connector.
F. Access the status screen on the electronic service tool.
G. While the status for the “Clutch Pedal Position Switch” is being monitored on the electronic service tool, connect the switch wires and disconnect the switch wires.
Expected Result:
When the switch wires are connected the status for the “Clutch Pedal Position Switch” is “Off”. When the switch wires are disconnected the status for the “Clutch Pedal Position Switch” is “On”.
Results:
• OK – The wiring between the clutch pedal position switch and the ECM is OK.
Repair: Replace the faulty switch.
Verify that the repair eliminates the problem.
STOP.
• Not OK – There is a problem in the harness between the switch and the ECM. Proceed to Test Step 6.
Test Step 6. Insert a Jumper at the Bulkhead Connector
A. Turn the key switch to the Off position.
B. Fabricate a jumper wire 100 mm (4 inch) long. Crimp a Deutsch pin to both ends of the wires.
C. Locate the clutch switch terminal and find the AP Sensor/Switch Sensor Common terminal on the engine side of the bulkhead connector.
D. Insert the jumper wire between the two terminals in the engine side of the bulkhead connector.
E. Turn the key switch to the On position.
F. Connect the electronic service tool to the data link connector.
G. Access the status for the “Clutch Pedal Position Switch” on the electronic service tool.
H. While the status for the “Clutch Pedal Position Switch” is being monitored on the electronic service tool, remove the jumper wire between the two terminals and insert the jumper wire between the two terminals.
Expected Result:
When the jumper wire is installed, the status for the “Clutch Pedal Position Switch” is “Off”. When the jumper wire is removed, the status for the “Clutch Pedal Position Switch” is “On”.
Results:
• OK – The problem is in the vehicle wiring between the bulkhead connector and the switch.
Repair: Perform the following repair:
Inspect the vehicle wiring and repair the vehicle wiring, as required. If the problem still exists with the wiring, send the vehicle to the OEM dealer.
STOP.
• Not OK – The problem is in the vehicle wiring between the bulkhead connector and the ECM.
Repair: Perform the following repair:
Inspect the vehicle wiring and repair the vehicle wiring, as required. If the problem still exists with the wiring, send the vehicle to the OEM dealer.
STOP.
