924089 Volvo.Penta Stud

Table 1
J1939 Code CDL Code Comments
N/A 1076-5
Engine Cooling Fan Bypass Solenoid open circuit The Electronic Control Module (ECM) detects an open circuit in the circuit for the engine cooling fan bypass solenoid.
The ECM sends minimum current to the fan control solenoid. The code is logged.
N/A 1076-6
Engine Cooling Fan Bypass Solenoid short to ground The ECM detects a short circuit to ground in the circuit for the engine cooling fan bypass solenoid.
The ECM sends minimum current to the fan bypass solenoid. The code is logged. The cooling fan bypass solenoid is used in areas with cold ambient temperatures. Under normal operating circumstances, the main cooling fan never turns off. The main cooling fan continues to operate at a minimum speed regardless of need. When the cooling fan bypass solenoid is activated, hydraulic flow to the fan motor will be bypassed. The result is no fan speed or slow fan speeds.The following conditions must be met in order for the cooling fan bypass solenoid to activate.
The temperature of the hydraulic oil must be between 50 °C (122 °F) and 100 °C (212 °F).
The intake manifold air temperature must be less than a map-dependent value that is based on engine rpm.
The coolant temperature must be below 88 °C (190 °F).
The engine speed must be between 500 rpm and 1500 rpm.Note: The ECM will only detect an open in the circuit if the cooling fan bypass solenoid is not activated. The ECM will only detect a short in the circuit if the cooling fan bypass solenoid has been activated.
Illustration 1 g02308317
Schematic for the cooling fan bypass solenoid
Table 2
Troubleshooting Test Steps Values Results
1. Check for Active Diagnostic Codes
A. Turn the keyswitch to the ON position.
B. Verify that the solenoid connector is free of debris and connected securely.
C. Connect Cat ET to the service tool connector.
D. Restore the electrical power to the ECM.
E. Select diagnostic tests from Cat ET.
F. Select the "Override Parameters" screen on Cat ET.
G. Activate the fan override.
H.Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.
Wait at least 30 seconds in order for the diagnostic code to become active.
I. Disable the fan override.
Active Diagnostic Codes
Result: No diagnostic codes are active.
The problem may have been related to a faulty connection in the harness. Carefully inspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Result: A short circuit diagnostic code (-6) is active currently.
Proceed to Test Step 2.
Result: An open circuit diagnostic code (-5) is active currently.
Proceed to Test Step 3.
2. Create an Open Circuit at the Connector for the Cooling Fan Bypass
A. Turn the keyswitch to the OFF position.
B. Disconnect the connector for the engine fan control solenoid.
C. Turn the keyswitch to the ON position.
D. Activate the fan override.
E. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.
Wait at least 30 seconds in order for the diagnostic code to become active.
F. Disable the fan override.
Short Circuit
Result: A short circuit diagnostic code (-6) remains active. There is a short circuit between the harness connector for the engine fan control solenoid and the ECM.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Reset all active codes and clear all logged codes. Verify that the problem is resolved.
Result: A short circuit diagnostic code (-6) was active before disconnecting the connector. An open circuit diagnostic code (-5) became active after disconnecting the connector.
Repair: Replace the engine fan control solenoid. Reset all active codes and clear all logged codes. Verify that the problem is resolved.
3. Create a Short at the Connector for the Cooling Fan Bypass Solenoid
A. Turn the keyswitch to the OFF position.
B. Fabricate a jumper wire that is long enough to create a short between the terminals of the connector for the cooling fan bypass solenoid. Crimp connector pins to each end of the jumper wire.
C. Install the jumper wire between terminal 1 (engine fan control solenoid) and terminal 2 (solenoid return) on the harness side of the connector.
D. Turn the keyswitch to the ON position.
E. Activate the cooling fan bypass solenoid.
F. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.
Wait at least 30 seconds in order for the diagnostic code to become active.
Disable the fan override for the cooling fan bypass solenoid. Remove the jumper wire.
Open Circuit
Result: The open circuit diagnostic code (-5) remains active with the jumper in place.
Repair: Repair the connectors or wiring and/or replace the connectors or wiring. Reset all active codes and clear all logged codes. Verify that the problem is resolved.
Result: A short circuit diagnostic code (-6) is active when the jumper wire is installed. An open circuit diagnostic code (5) is active when the jumper wire is removed.
Repair: Replace the engine fan control solenoid. Reset all active codes and clear all logged codes. Verify that the problem is resolved.
4. Check the Operation of the ECM
A. Disconnect the J1/P1 ECM connector.
B. Fabricate a jumper wire that is long enough to create a short between the ECM connector and engine ground. Crimp a connector socket to one end of the jumper wire.
C. Remove the wire from terminal location P1-43 (cooling fan bypass solenoid) at the ECM connector. Install the jumper wire into this terminal location.
D. Connect the J1/P1 ECM connector.
E. Create an open at the ECM:
1. Turn the keyswitch to the ON position.
Do not allow the loose end of the jumper wire to connect to any other wires or to engine ground.
2. Monitor the "Active Diagnostic Code" screen on Cat ET. Check and record any active diagnostic codes.
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
3. Select diagnostic tests from Cat ET.
4. Select the "Override Parameters" screen on Cat ET.
5. Activate the override for the cooling fan bypass solenoid.
6. Monitor the active diagnostic code screen on Cat ET. Check and record any active diagnostic codes.
Note: Wait at least 30 seconds in order for the diagnostic codes to become active.
7. Disable the override for the cooling fan bypass solenoid.
F. Create