0326264 JOHNSON GASKET, Exhaust cover inner

Table 1
Diagnostic Codes Table
Code Conditions which Generate this Code System Response
524-3 Desired Engine Speed Sensor : Voltage Above Normal The Electronic Control Module (ECM) has been powered up for at least five seconds. The current to the ECM for the desired speed input is greater than 22 mA for more than five seconds. When the "Idle/Rated" switch is in the "Rated" position, the ECM assumes a default value for the desired engine speed.
The default value for the desired engine speed is equal to the "Minimum Engine High Idle Speed" that is programmed on the "Service/Configuration" screen of Caterpillar Electronic Technician (ET).
The alarm output is activated. The code is logged.
524-4 Desired Engine Speed Sensor : Voltage Below Normal The ECM has been powered up for at least five seconds. The current to the ECM for the desired speed input is less than 2 mA for more than five seconds. Note: For this troubleshooting procedure, the "Desired Speed Input" configuration parameter must be set to "4-20 mA Input" in the "Service/Configuration" screen of Cat ET. The selection of this setting requires a 4 to 20 mA signal for regulation of the desired engine speed. If the "Desired Speed Input" is set to "0-5 VDC Input", do not use this procedure to troubleshoot the circuit.When the desired speed input is correspondingly configured, the ECM controls the engine speed according to the 4 to 20 mA current.The value of the current corresponds to a range of desired engine speeds between minimum high idle and maximum high idle. The "Minimum Engine High Idle Speed" and the "Maximum Engine High Idle Speed" are set with the "Service/Configuration" screen of Cat ET. For more information, refer to Systems Operation/Testing and Adjusting, "Electronic Control System Parameters".When the "Idle/Rated" switch is in the Rated position, a current value of 4.0 mA corresponds to the programmed "Minimum Engine High Idle Speed". A current value of 20.0 mA corresponds to "Maximum Engine High Idle Speed". Current values within this range will vary the desired engine speed in a linear fashion between "Minimum Engine High Idle Speed" and "Maximum Engine High Idle Speed".The ECM will generate a diagnostic code in response to current outside of the range of 4 to 20 mA.Current values that are greater than 22 mA will activate the "524-3 Desired Engine Speed Sensor short to +batt" diagnostic code. Current values that are less than 2 mA will activate the "524-4 Desired Engine Speed Sensor short to ground" diagnostic code. The most likely causes of the diagnostic code are a poor connection or a problem in a wiring harness. The next likely cause is a problem with a component. The least likely cause is a problem with the ECM.Logged diagnostic codes provide a historical record. Before you begin this procedure, use Cat ET to print the logged codes to a file.The troubleshooting procedure may generate additional diagnostic codes. Keep your mind on correcting the cause of the original diagnostic code. Clear the diagnostic codes after the problem is resolved.
Illustration 1 g01442077
Schematic of the 4 to 20 mA desired speed input
Test Step 1. Inspect the Electrical Connectors and Wiring
Illustration 2 g01431198
Terminal Box
(1) ECM connector J2/P2
(2) ECM connector J1/P1
(3) 16 amp circuit breaker
(4) Connectors J3/P3 for the customer's connector
(5) Connectors J4/P4 for the optional control panel (if equipped) or for a customer's connector
(6) J5/P5 connectors for the harness
(7) J6/P6 connectors for the harness
Turn the engine control switch to the OFF/RESET position. Switch the 16 amp circuit breaker for the ECM OFF. Note: For the following steps, refer to Troubleshooting, "Electrical Connectors - Inspect".
Thoroughly inspect the following components:
ECM J1/P1 connectors
Customer connectors J3/P3 (if equipped)
Terminal box's J4/P4 connector for the control panel (if equipped)
Terminal strip in the control panel (if equipped)
Wiring and the connections between the terminal box and the device that supplies the 4 to 20 mA signal
Check the allen head screw on each of the ECM connectors for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Illustration 3 g01442148
Harness side of the ECM P1 connector
(P1-36) + Signal
(P1-37) − Signal
(P1-70) +Battery(keyswitch)
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the 4 to 20 mA circuit.
Inspect the terminal strip in the control panel (if equipped) for the following conditions: loose wires, frayed wires, foreign objects and corrosion.
Check the harness and wiring for abrasion and for pinch points between the device that supplies the 4 to 20 mA signal and the ECM. Expected Result:All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points.Results:
OK - All connectors, pins, and sockets are connected properly. The connectors and the wiring do not have corrosion, abrasion, or pinch points. The components are in good condition with proper connections. If you are troubleshooting a 524-3 diagnostic code, proceed to Test Step 2. If you are troubleshooting a 524-4 diagnostic code, proceed to Test Step 4.
Not OK - At least one of the connectors, pins, or sockets is not connected properly. At least one connector or wire has corrosion, abrasion, and/or pinch points. The components are not in good condition and/or at least one connection is improper.Repair: Perform the necessary repairs and/or replace parts, if necessary.STOPTest Step 2. Check for a Short Circuit to the +Battery Side at the ECM P1 Terminal 36
Verify that the engine control switch is in the OFF/RESET position and the 16 amp circuit breaker for the ECM OFF.
Make sure that there is no electrical power to the device that provides the 4 to 20 mA signal.
Remove the two wires ("+" and "-") for the 4 to 20 mA signal from the device that supplies the 4 to 20 mA signal. Tape the leads in order to ensure that the leads do not contact any object.
Disconnect the ECM P1 connector.
Use an ohmmeter to measure the resistance between terminals P1-36 and P1-70. Expected Result:The resistance is greater than 20,000 Ohms.Results:
OK - The resistance is greater than 20,000 Ohms. The wiring from terminal P1-36