22211432 Volvo.Penta Bracket

Table 1
Diagnostic Codes Table
CDL Code Code Description Comments
2734-2 Compression Brake Switch : Erratic, Intermittent, or Incorrect
2734-3 Compression Brake Switch : Voltage Above Normal
2734-4 Compression Brake Switch : Voltage Below Normal Operation of the engine retarder switchThe engine retarder switch is a momentary push button switch that is in the pedal assembly that is on the floor of the cab. This switch is used to select the operating mode of the engine retarders by the operator. There are two control modes for the engine retarder that are available to the operator, auto mode and manual mode.The auto mode is selected when the engine retarder switch is in the released position. In auto mode, the retarder will be activated only when the engine speed is above 2100 rpm. The retarder will remain on until the engine speed falls below 1750 rpm.The manual mode is selected when the engine retarder switch is actuated continuously by the operator. In the manual mode, the engine retarder will be activated only when the engine speed is above 1500 rpm. The retarder will remain on until the engine speed falls below 1400 rpm, or the engine retarder switch is released.While compression brake operation is directly controlled by the engine ECM, the transmission ECM provides an interlock control for protection of the transmission and of the drive train. This interlock control ensures that the operating conditions for the engine, the transmission, and the machine are favorable prior to enabling the compression brakes. Once the conditions are met, the transmission ECM communicates a favorable status of the interlock control over the Cat Data Link to the engine ECM. The engine ECM then has direct control over the operation of the compression brakes. A problem with communications between the engine ECM and the transmission control will affect operation of the compression brake. The transmission control will restrict operation to the automatic mode during an active fault for the compression brake switch.Operation of the right brake pedal switchThe right brake pedal switch is a momentary contact switch. The ECM uses the switch inputs for the right brake pedal switch in order to detect the status of the right brake pedal switch. The ECM uses this status information in order to disengage the throttle lock control when the brake is depressed. The throttle lock feature is used by the operator in order to maintain a desired engine speed.Both of these switches are momentary switches that provide two switch inputs to the ECM. One of these inputs is normally open and the other input is normally closed.Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the engine ECM.
Illustration 1 g02126664
Location of the J1/P1 ECM connectors (typical left side engine view)
Thoroughly inspect the J1/P1 ECM connectors and the connectors for each switch. Also inspect each of the machine connectors that are in the circuit. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Illustration 2 g02126667
Terminal locations at the P1 ECM connector for the switch circuits
(P1-5) Digital return
(P1-44) Retarder switch (NC)
(P1-49) Retarder switch (NO)
Perform a 45 N (10 lb) pull test on each of the wires for the suspect switch.
Check the torque of the allen head screw on each of the ECM connectors. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points from the switch back to the ECM.Expected Result:Allof the connectors, pins and sockets are completely coupled and/or inserted and the harness and wiring are free of corrosion, of abrasion and of pinch points.Results:
OK - The harness and the connectors appear to be OK. Proceed to Test Step 2.
Not OK - There is a problem with the connectors and/or wiring.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. 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.STOPTest Step 2. Check for Active Diagnostic Codes
Connect Caterpillar Electronic Technician (ET) to the service tool connector.
Restore the electrical power to the engine ECM.Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
Check the "Active Diagnostic Codes" screen for an active code for one of the switches. Toggle the suspect switch as you monitor Cat ET for the active diagnostic code.
Remove electrical power from the engine ECM.Expected Result:A diagnostic code that is related to one of the switches is not active.Results:
OK - A diagnostic code that is related to one of the switches does not become active.Repair: The switches are operating normally. There may be an intermittent problem in the wiring harness or in a connector. Check the wiring harness and the connectors for an intermittent electrical problem. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A diagnostic code for one of the switches is active. Proceed to Test Step 3.Test Step 3. Create a short at the Connector for the Suspect Switch and Check for Diagnostic Codes
Disconnect the connectors for the suspect switch.
Fabricate a jumper wire that is long enough to create a test circuit at the connector for the suspect switch. Crimp a connector pin to both ends of the jumper wire.
Install the jumper wire between the terminal for the normally closed contact and the terminal for the digital return on the harness side of the connector for the suspect switch.
Restore the electrical power to the engine ECM.
Check the "Active Diagnostic Codes" screen on Cat