BOLT 2860466 - Caterpillar

System Operation Description:Note: Valid only if engine is equipped with an engine coolant diverter.Use this procedure to troubleshoot any suspect problems with the solenoid circuit for the coolant diverter valve.This procedure covers the following diagnostic codes:
284-05 Engine Coolant Diverter current low
284-06 Engine Coolant Diverter current highDuring normal operation, coolant is sent to the air intake system in order to cool the intake air. A jacket water aftercooler in the air lines after the turbochargers cools the air before the air enters the air-to-air aftercooler. When the vehicle is at idle in cold climates, the aftercooler may overcool the engine. The coolant diverter valve stops the flow of coolant to the aftercooler in order to prevent the coolant temperature from becoming too low. Diverting the coolant will also prevent the temperature in the cab from becoming too low."Coolant Diverter Valve Test"The "Coolant Diverter Valve Test" is a diagnostic test that is available on the Caterpillar Electronic Technician (ET). The test helps diagnose problems with the solenoid for the coolant diverter valve. A small current is applied to the circuit at all times. This allows the Engine Control Module (ECM) to detect open circuits when the valve is not actuated. A short circuit will only be detected when the valve is actuated.The following conditions must be met before the "Coolant Diverter Valve Test" will function:
Engine speed is 0.
Vehicle speed is 0.
The neutral switch is in the Neutral position.
Illustration 1 g01098796
Schematic
Illustration 2 g01098798
P2 ECM connector
(5) Solenoid for the coolant diverter valve
(79) Return for the intake valve actuator Test Step 1. Inspect Electrical Connectors and Wiring
Turn the key switch to the OFF position.
Thoroughly inspect the J2/P2 ECM connector and the solenoid connector. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the solenoid connector.
Check the ECM connector (allen head screw) for the proper torque of 6 N m (55.0 lb in).
Check the harness and wiring for abrasion and for pinch points. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted and the harness and the wiring are free of corrosion, of abrasion, or of pinch points.Results:
OK - The harness and wiring are OK. Proceed to Test Step 2.
Not OK - There is a problem in the connectors and/or wiring.Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled.Verify that the repair eliminates the problem.STOPTest Step 2. Check for Active Diagnostic Codes
Connect the Cat ET to the service tool connector.
Turn the key switch to the ON position.
Check for active diagnostic codes that are related to the coolant diverter valve.
Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes. Note: Wait at least 15 seconds in order for the diagnostic codes to become active.
Determine if the problem is related to the low