COIL AS 2186806 - Caterpillar

Illustration 1 g00860104
Schematic of the +8 Volt Sensor SupplyThe diagnostic code is recorded when the power train electronic control module (ECM) indicates that the voltage of the sensor supply circuit is too low. Possible causes of this diagnostic code are listed:
The output of sensor supply has an open circuit.
The torque converter speed sensor is faulty or the transmission oil temperature is faulty.System Response:The machine response is listed:
The lockup clutch is disabled.
Hesitation during direction shifts.
Calibrations will not function.Test Step 1. CHECK THE VOLTAGE AT THE ECM.
Turn the disconnect switch and the key start switch to the ON position.
Check the voltage at the ECM connector from contact J2-12 (sensor supply) to contact J1-16 (ground). Use the 7X-1710 Cable probes to measure the voltage. Do NOT disconnect the machine harness from the ECM. Expected Result:The voltage is 8.0 0.5 DCV or the voltage is 10.0 0.5 DCV.Results:
OK - The voltage is 8.0 or 0.5 DCV or the voltage is 10.0 0.5 DCV. The sensor supply voltage is correct. Verify that the diagnostic code is present. If the diagnostic code is still present the ECM has failed.Repair: It is unlikely that the ECM has failed. Exit this procedure and perform this procedure again. Also, recheck if the diagnostic code is active. If the cause of the diagnostic code is not found, replace the ECM. See Testing and Adjusting, "Electronic Control Module (ECM) - Replace". Stop.
NOT OK - Voltage is NOT 8.0 0.5 DCV or the voltage is 10.0 0.5 DCV. The voltage is less than 8.0 0.5 DCV or the voltage is 10.0 0.5 DCV. The sensor supply voltage is NOT correct. Proceed to test step 2.Test Step 2. CHECK FOR A SHORT TO GROUND.
Turn the key start switch and the disconnect switch to the OFF position.
Disconnect the machine harness from the ECM.
At the harness connector for the ECM, measure the resistance between frame ground and contact J2-12 and J1-16 of the sensor supply circuit. Expected Result:The resistance is greater than 5000 ohms.Results:
OK - The resistance is greater than 5000 ohms. The