856842 Mercury ELBOW

Table 1
Diagnostic Codes Table    
Code and Description    Conditions which Generate this Code    System Response    
296-9 Transmission Control abnormal update rate     Communication with the transmission control cannot be established within three seconds after the Electronic Control Module (ECM) is powered up. After communication with the transmission control has been established, communication stops for one second.     The ECM will log the diagnostic code. All features of the transmission control that rely on the data link are disabled. The ECM will disable the automatic control of engine speed through the throttle lock feature.    
588-9 Monitoring System Display abnormal update rate     Communication with the monitoring system cannot be established within three seconds after ECM powerup. After communication with the monitoring system has been established, communication stops for one second.     The ECM will log the diagnostic code. All features of the monitoring system that rely on the data link are disabled.    
596-9 Implement Control abnormal update rate     Communication with the implement control cannot be established within three seconds after ECM powerup. After communication with the implement control has been established, communication stops for one second.     The ECM will log the diagnostic code. All features of the implement control that rely on the data link are disabled.    
1639-2 Machine Security System Module erratic, intermittent, or incorrect     Communication with the machine security system cannot be established within three seconds after ECM powerup. After communication with the machine security system has been established, communication stops for one second.     The ECM will log the diagnostic code. All features of the machine security system that rely on the data link are disabled.    
1639-9 Machine Security System Module abnormal update rate     Communication with the machine security system cannot be established within three seconds after ECM powerup. After communication with the machine security system has been established, communication stops for one second.     The ECM will log the diagnostic code. All features of the machine security system that rely on the data link are disabled.    Note: This procedure checks for an open circuit or for a short circuit in the Cat Data Link. If you are experiencing problems with communications between Caterpillar Electronic Technician (ET) and the ECM, refer to Troubleshooting, "Electronic Service Tool Does Not Communicate" before you use this procedure.The Cat Data Link is the standard data link that is used by the ECM to communicate with Cat ET. The ECM communicates with Cat ET in order to share status information and diagnostic information. Cat ET can also be used to configure the ECM parameters.
Illustration 1 g01394350
Typical schematic for the Cat Data Link
Illustration 2 g01394355
Service tool connector (Terminal D) Cat Data Link + (Terminal E) Cat Data Link −Test Step 1. Inspect the Electrical Connectors and the Wiring
Remove electrical power from the ECM.
Illustration 3 g01167488
Engine view (typical example) (1) J1/P1 ECM connectors
Thoroughly inspect connector (1). Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 4 g01104274
P1 terminals that are associated with the Cat Data Link (P1-8) Cat Data Link + (P1-9) Cat Data Link −
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the Cat Data Link.
Check the allen head screw on each ECM connector for the proper torque. Also, check the allen head screw on the customer connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.Expected Result:All connectors, pins, and sockets are completely inserted and coupled. 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 - The connectors and/or the wiring are not OK.Repair: Repair the connectors and/or the wiring. 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 original problem is resolved.STOPTest Step 2. Check for a Short Circuit
Disconnect the P1 ECM connector.
Disconnect Cat ET from the service tool connector.
Disconnect any other control modules from the Cat Data Link. Refer to the electrical schematic in order to identify other control modules on the Cat Data Link.
Measure the resistance between the points that are listed in Table 2. Be sure to wiggle the wires in the harnesses as you make each resistance measurement.
Table 2
Resistance Measurements for the Cat Data Link    
Connector and Terminal    Terminal    
P1-8 (Cat Data Link +)     All of the other terminals on the P1 connector    
Ground stud
P1-9 (Cat Data Link -)     All of the other terminals on the P1 connector    
Ground stud Expected Result:Each check of the resistance indicates an open circuit.Results:
OK - Each check of the resistance indicates an open circuit. Proceed to Test Step 3.
Not OK - At least one check of the resistance does not indicate an open circuit. There is a short circuit in the harness or in a connector.Repair: Repair the connectors and/or the wiring. Replace parts, if necessary. Verify that the original problem is resolved.STOPTest Step 3. Check for an Open Circuit
Fabricate a jumper wire. Use the jumper wire in order to create a short circuit between terminals D (Cat Data Link +) and terminal E (Cat Data Link −) on the service tool connector.
Measure the resistance between P1-8 (Cat Data Link +) and P1-9 (Cat Data Link −).
Measure the resistance between the terminals at the connector for each control module that was connected to the Cat Data Link. Refer to Illustration 1.
Remove the jumper wire from the service tool connector.Expected Result:Each check of the resistance indicates a short circuit.Results:
OK - Each check of the resistance indicates a short circuit.Repair: Perform the following procedure:
Connect the J1/