0325333 JOHNSON EXHAUST TUBE, Inner

Table 1
Diagnostic Codes Table
Code and Description Conditions which Generate this Code System Response
248-9 @CatDatalinkLong@ not communicating The Electronic Control Module (ECM) detects a loss of communication over the data link for two or more seconds. The code is logged. The Cat Data Link is used for communication between electronic modules. The data link is used to communicate information from the engine's ECM to Caterpillar Electronic Technician (ET). The data link is used for programming and for troubleshooting the ECM.The ECM communicates with Cat ET in order to share engine information that may affect engine operation. The ECM communicates with the Cat ET in order to share status and diagnostic information. Cat ET can also be used to configure the ECM parameters. This information will not be available if communications fail between the ECM and Cat ET.
Illustration 1 g01338352
Typical example
Illustration 2 g01241456
P1 ECM connector
(P1-8) Cat Data Link +
(P1-9) Cat Data Link −
Illustration 3 g01241457
Customer connector
(Terminal h) Cat Data Link +
(Terminal g) Cat Data Link −
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Service tool connector
(Terminal D) Cat Data Link +
(Terminal E) Cat Data Link −
Illustration 5 g01337991
Connector locations
(1) A-C1/E-C2 RH rigid harness connectors
(2) A-C2/J-C2 RH rigid harness connectors
(3) P-C1/A-C90 Connectors for the power distribution panel
(4) P-C2/A-C91 Connectors for the power distribution panel
(5) G-C6/F-C2/F-C1/A-C92 Connectors for a RH Control panel
(6) C-C22 Connection for the P2 ECM connector
(7) C-C15 Connection for the P1 ECM connector
(8) G-C6/F-C2/F-C1/C-C17 Connectors for a LH Control panel
(9) C-C18/TB-C1 Customer connectors
(10) C-C2/J-C1 LH rigid harness connectors
(11) C-C1/E-C1 LH rigid harness connectors Test Step 1. Inspect Electrical Connectors and Wiring
Turn the engine control switch (ECS) to the OFF/RESET position.
Thoroughly inspect the ECM connectors J1/P1. Inspect all of the other connectors for any module on the Cat Data Link. Refer to the diagnostic functional test Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with the circuit.
Check the allen head screw on each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness and the wiring for abrasion and for pinch points. Expected Result:All 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 connectors and wiring are OK. Proceed to Test Step 2.
Not OK - The connectors and/or wiring need repair.Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring.STOPTest Step 2. Check for Electrical Shorts in the Harness
Disconnect the ECM connectors.
Disconnect any module that is connected to the Cat Data Link.
Measure the resistance at the following points. Wiggle the harness during the measurement in order to reveal an intermittent short.
Cat Data Link + to Cat Data Link −
Cat Data Link + to −Battery terminal
Cat Data Link − to −Battery terminal
Cat Data Link + to +Battery terminal
Cat Data Link − to +Battery terminal
Cat Data Link + to engine ground
Cat Data Link − to engine groundExpected Result:The resistance measurement indicates an open circuit.Results:
OK - The resistance measurement indicates an open circuit. Proceed to Test Step 3.
Not OK - The resistance measurement indicates a short circuit. There is a short in the harness or in the connectors.Repair: Repair the connector and/or wiring or replace the connector and/or wiring.STOPTest Step 3. Check the Resistance through the Harness for an Open Circuit
Short the wires of the Cat Data Link together. Create the short at P1-9 and P1-8 of the ECM connector.
Set an ohmmeter on the 200 Ohm scale. Measure the resistance between the terminals of the Cat Data Link + and the Cat Data Link −. Measure the resistance at the connectors for the ECM. Measure the resistance between the terminals of any module that was connected to the Cat Data Link. Wiggle the harness during the measurements in order to reveal an intermittent open condition.
Reconnect all connectors and modules. Expected Result:The resistance measurement indicates a short circuit.Results:
OK - The resistance measurement indicates a short circuit.Repair: The harness is OK. There could be a problem with a module or with the ECM. Connect the suspect module on another engine. If the problem returns on the other engine, replace the suspect module. Turn the ECS to the OFF/RESET position. Turn the ECS to the STOP position. If the diagnostic code is still present, replace the ECM. Refer to Troubleshooting, "ECM - Replace".STOP
Not OK - The resistance measurement indicates an open circuit.Repair: There is an open circuit or there is excessive resistance in the harness. Repair the connectors and/or wiring or replace the connectors and/or wiring.STOP