54790 Mercruiser STUD, CRANKSHAFT BEARING CAP AND OIL PAN BAFFLE

Table 1
Diagnostic Trouble Codes for the Data Link Circuit
J1939 Code CDL Code Code Description Comments
- 248-9 Cat Data Link: Abnormal Update Rate The engine ECM detects a loss of communications with the Cat data bus.
The ECM will log the diagnostic code.
The engine will not start. The following background information is related to this procedure:The data link is the standard data link that is used by the ECM in order to communicate with the electronic service tool.The ECM provides multiple connections for the data link. The technician must ensure that the correct connector is being tested. The connection that is used is dependent on the application.If the diagnostic connector is off the engine, the positive data link signal will be from P1:20 to pin "D" of the diagnostic connector. The negative data link signal will be from P1:28 to pin "E" of the diagnostic connector.If the diagnostic connector is on the engine, the positive data link signal will be from P2:47 to pin "D" of the diagnostic connector. The negative data link signal will be from P2:55 to pin "E" of the diagnostic connector.The following information refers to the pin number. Ensure that the correct connector is used.CommunicationThe electronic service tool may indicate the following error message:The version of the ECM is not recognized and the integrity of the changed parameters and displayed data is not guaranteed.This message will indicate that the version of the software that is in the electronic service tool is obsolete. Install the latest version of the software for the electronic service tool in order to rectify the fault.
Illustration 1 g03705762
Schematic of the diagnostic connector and the data link connector for a diagnostic connector that is mounted off engine
Illustration 2 g03705767
Schematic of the diagnostic connector and the data link connector for an engine mounted diagnostic connector
Illustration 3 g03134661
P1 pin locations for the diagnostic connector
(20) Data link +
(28) Data link -
Illustration 4 g03134662
Typical view of the P2 pin locations for the diagnostic connector
(47) Data link +
(55) Data link -
(56) Voltage supply (diagnostic connector)
(64) Return (diagnostic connector) Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position.
B. Inspect the connectors in the circuit for the data link.
Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires that are associated with the CAN data link.
D. Check the screw for the P1 and P2 ECM connectors for correct torque of 6 N m (53 lb in).
E. Check all of the wiring associated with the data link for abrasions and pinch points.
Damaged wire or connector
Result: A damaged wire or damaged connector was found.
Repair: Repair the damaged wire or the damaged connector.
Use the electronic service tool to clear all logged diagnostic codes. Verify that the repair eliminates the fault.
Result: A damaged wire or damaged connector was not found.
Proceed to Test Step 2.
2. Determine the Type of Fault in the Data Link
A. Connect the electronic service tool to the diagnostic connector that is on the engine harness or on the application.
Repair: Turn the keyswitch to the ON position.
Power to the comms adapter
Result: The power lamp illuminates on the communications adapter. The communications adapter is currently receiving the correct voltage.
Proceed to Test Step 5.
Result: The power lamp is not illuminated on the communications adapter. The communications adapter is not currently receiving the correct voltage.
Proceed to Test Step 3.
3. Check the Battery Voltage at the Diagnostic Connector
A. Turn the keyswitch to the ON position.
B. Use a multimeter in order to measure the voltage from pin A (battery+) and pin B (ground) of the diagnostic connector.
11.0 VDC and 13.5 VDC for a 12 VDC system. 22.0 VDC and 27.0 VDC for a 24 VDC system.
Result: The voltage is between 22.0 VDC and 27.0 VDC for a 24 V system. The voltage is between 11.0 VDC and 13.5 VDC for a 12 V system. The diagnostic connector is currently receiving the correct voltage.
Proceed to Test Step 5.
Result: The voltage is not between 22.0 VDC and 27.0 VDC for a 24 V system. The voltage is not between 11.0 VDC and 13.5 VDC for a 12 V system. The diagnostic connector is not currently receiving the correct voltage.
Proceed to Test Step 4.
Illustration 5 g03705906
Typical view of the diagnostic connector from the wire side
(A) Switched battery +
(B) Battery ground (GND)
(D) Data link +
(E) Data link -
Table 3
Troubleshooting Test Steps Values Results
4. Bypass the Wiring for the Diagnostic Connector
A. Disconnect the wires from pin A and pin B of the diagnostic connector.
Note: If the diagnostic connector is mounted on the engine, perform Steps B to D. If the diagnostic connector is mounted off the engine, perform Step E.
B. Disconnect the wires from P2:56 and P2:64.
C. Fabricate a jumper wire in order to connect pin A of the diagnostic connector to P2:56.
D. Fabricate a jumper wire in order to connect pin B of the diagnostic connector to P2:64.
E. Fabricate a jumper wire in order to connect pin "A" of the diagnostic connec