24820-ZW1-V21 Honda HOUSING ASSY., REMOTE CONTROL (Honda Code 4898730). BOX (A)

Table 1
Diagnostic Codes    
Code and Description     Conditions which Generate this Code     System Response    
1900-5 Engine Coolant Diverter Solenoid : Current Below Normal     The ECM detects an open circuit.     The code is logged    
1900-6 Engine Coolant Diverter Solenoid : Current Above Normal     The ECM detects a short circuit.    During normal operation, the diverter valve directs warm jacket water coolant through the aftercooler to warm combustion air going to the cylinders. The ECM regulates the inlet manifold air temperature by sending a control signal to the diverter valve to regulate the coolant flow through the aftercooler.The coolant diverter valve will operate until the inlet manifold air temperature reaches 30° C (86° F). The ECM will then close the coolant diverter valve to prevent warm coolant from circulating through the aftercooler. If the inlet manifold temperature drops below 20° C (68° F), the ECM will operate the coolant diverter valve in order to allow warm coolant to circulate through the aftercooler."Coolant Diverter Valve Test"The "Coolant Diverter Valve Test" is a diagnostic test that is available on the Cat® Electronic Technician (Cat® 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. The small current 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.
Illustration 1 g03374859
Illustration 2 g03374861
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 lb in).
Check the harness and wiring for abrasion and for pinch points.Expected Result:All connectors, pins, and sockets are completely coupled 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 current diagnostic code 05 or the high current diagnostic code 06.Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active.Repair: The problem may have been related to a faulty connection in the harness. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A low current diagnostic code (05) is active at this time. Proceed to Test Step 3.
Not OK - An high current diagnostic code (06) is active at this time. Proceed to Test Step 4.Test Step 3. Create a Short Circuit at the Harness Connector for the Solenoid
Turn the key switch to the OFF position.
Disconnect the connector for the coolant diverter valve.
Fabricate a jumper wire to short terminal A and terminal B of the connector for the solenoid on the engine harness.
Turn the key switch to the ON position.
Access the "Special Tests" under the "Diagnostics" menu.
Start the "Coolant Diverter Valve Test" on Cat ET.
Once Cat ET displays the status of the coolant diverter valve, stop the "Coolant Diverter Valve Test".Expected Result:The test indicated "Not Active: Device Short" with the jumper wire in place.Results:
OK - The test indicated "Not Active: Device Short". The ECM recognized the short at the connector for the coolant diverter valve. The harness wiring is OK.Repair: Temporarily connect a new coolant diverter valve to the harness, but do not install the new coolant diverter valve on the engine. Verify that there are no active diagnostic codes for the coolant diverter valve. If there are no active diagnostic codes for the coolant diverter valve, permanently install the new coolant diverter valve. Clear any logged diagnostic codes.STOP
Not OK - The test indicated "Not Active: Device Open". The ECM did not see the short at the connector for the coolant diverter valve. Proceed to Test Step 5.Test Step 4. Create an Open at the Harness Connector for the Solenoid
Turn the key switch to the OFF position.
Disconnect the connector for the coolant diverter valve.
Turn the key switch to the ON position.
Access the "Special Tests" under the "Diagnostics" menu.
Start the "Coolant Diverter Valve Test" on Cat ET.
Once Cat ET displays the status of the coolant diverter valve, stop the "Coolant Diverter Valve Test".Expected Result:The test indicates "Not Active: Device Open".Results:
OK - The test indicates "Not Active: Device Open". The ECM recognized the open at the connector for the coolant diverter valve. The harness wiring is OK.Repair: Temporarily connect a new coolant diverter valve to the harness, but do not install the new coolant diverter valve on the engine. Verify that there are no active diagnostic codes for the coolant diverter valve. If there are no active diagnostic codes for the coolant diverter valve, permanently install the new coolant diverter valve. Clear any logged diagnostic codes.STOP
Not OK - The test indicates "Not Active: Device Short". Proceed to Test Step 6.Test Step 5. Short the Circuit at the ECM
Turn the key switch to the OFF position.
Disconnect the P2 ECM connector.
Remove the wires from P2-11 (coolant diverter valve) and P2-21 (return for the coolant diverter valve).
Fabricate a jumper wire