HOUSING AS-TURBINE 4W7636 - Caterpillar

Conditions Which Generate This Code:
Illustration 1 g00545923
System Schematic For CCM Data LinkThis "CCM data link" is not used for MUI applications. It is unlikely for a CID 770 to occur. However, the connector contacts 21 and 22 are present. Therefore, a fault is possible. The possible causes of a CID 0770 FMI 09 are listed below.
A short to the + battery ("B+") of either one of the two contacts, 21 or 22
A short to battery negative ("B-") of either of the two connector contacts, 21 or 22Note: The GSC+ cannot detect an open in the circuit of the "CCM data link". Troubleshoot and repair the wiring. See Testing And Adjusting, "Schematic And Wiring Diagrams".Test Step 1. CHECK THE CCM FOR A SHORT TO +BATTERY
Turn the ECS to the OFF/RESET position.
Disconnect the + and - battery leads from the battery.
Measure the resistance between contacts 21 and +B.
Measure the resistance between contacts 22 and +B.Expected Result:The resistance is greater than 5000 ohms for both cases.Results:
OK - The resistance is greater than 5000 ohms for both cases. The circuit is correct. Proceed to test step 2.
NOT OK - The resistance is less than 5000 ohms. The circuit is not correct.Repair: The "CCM data link" is shorted to B+. Repair the wiring or replace the wiring.The GSC+ treats a CID 770 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the engine control switch (ECS) is in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after the troubleshooting is complete. Stop.Test Step 2. CHECK THE CCM FOR A SHORT TO -BATTERY
Turn the ECS to the OFF/RESET position.
Disconnect the + and - battery leads from the battery.
Measure the resistance between contacts 21 and -B.
Measure the resistance between contacts 21 and -B.Expected Result:The resistance is greater than 5000 ohms for both cases.Results:
OK - The resistance is greater than 5000 ohms for both cases. The circuit is correct.Repair: The failure is intermittent. The probable cause is a poor electrical connection. Check the wiring and repair the wiring, as needed.The GSC+ treats a CID 770 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the engine control switch (ECS) is in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after the troubleshooting is complete. Stop.
NOT OK - The resistance is less than 5000 ohms. The circuit is not correct.Repair: The CCM data link is shorted to B-. Repair the wiring or replace the wiring.The GSC+ treats a CID 770 as an alarm fault. Active alarm faults are shown on the display when the alarm codes key is pressed and the engine control switch (ECS) is in any position except the OFF/RESET position. Clear the diagnostic code from the fault log after the troubleshooting is complete. Stop.