3861770 Volvo.Penta Engine control unit

Illustration 1 g01384979
Schematic diagram for the active temperature sensor
Illustration 2 g01385632
View of the pin locations on the P1 connector
(34) Ground (GND)
(42) Voltage supply (5 Volts DC)
(54) Signal (SIG)
Illustration 3 g01385625
Active temperature sensor
(A) Voltage supply (5 Volts DC)
(B) Ground (GND)
(C) Signal (SIG) The temperature sensor is an active sensor. The temperature sensor has three terminals. Active sensors require supply voltage from the ECM. The P1 ECM connector supplies +5 Volts to terminal A of the sensor. The common line is connected to the sensor connector terminal B. The signal voltage from terminal C of the sensor is supplied to terminal 54 on the P1 ECM connector.Test Step 1. Verify All Active Diagnostic Codes
Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
Verify if any of the following diagnostic codes are active:
1796-03 Intake Manifold #2 Air Temperature Sensor voltage above normal
1796-04 Intake Manifold #2 Air Temperature Sensor voltage below normalExpected Result:One or more of the preceding diagnostic codes are active.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: When this test is complete, return to the start of this test. If the preceding codes are logged, an intermittent condition may be causing the logged codes. Refer to Troubleshooting, "Electrical Connectors - Inspect".Perform a "Wiggle Test" by using the electronic service tool in order to identify intermittent connections.STOPTest Step 2. Inspect Electrical Connectors And Wiring
Thoroughly inspect the terminal connections on the P1/J1 ECM connectors.
Thoroughly inspect the connector for the second intake manifold air temperature sensor.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector and the sensor connector that are associated with the active diagnostic code.
Check the screws for the ECM connectors for the correct torque of 5 N m (44 lb in).
Check the harness for abrasions and for pinch points from the sensors back to the ECM.
Use the electronic service tool to perform a "Wiggle Test". The "Wiggle Test" will identify intermittent connections. Expected Result:All connectors, pins, and sockets should be completely coupled and inserted. The harness should be free of corrosion, abrasions and pinch points.Results:
OK - Proceed to Test Step 3.
Not OK - Repair: Repair the connectors or the harness and/or replace the connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are completely coupled.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 3. Verify that the Diagnostic Code is Still Active
Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
Use the electronic service tool to check for active diagnostic codes. Record all active diagnostic codes.
Determine if the fault is related to an open circuit diagnostic code or a short circuit diagnostic code. Expected Result:Either a short circuit diagnostic code is active or an open circuit diagnostic code is active.Results:
OK - Short Circuit - A voltage above normal diagnostic code is active at this time. Proceed to Test Step 4.
OK - Open Circuit - A voltage below normal diagnostic code is active at this time. Proceed to Test Step 5.
Not OK - A short circuit diagnostic code is not active. An open circuit diagnostic code is not active. An intermittent fault may exist.Repair: Use the electronic service tool to perform a "Wiggle Test". If faults are indicated then go to the appropriate procedure. STOPTest Step 4. Disconnect The Sensor In Order To Create An Open Circuit
Turn the keyswitch to the OFF position.
Disconnect the sensor connector.
Turn the keyswitch to the ON position. Wait at least 10 seconds for activation of the diagnostic codes.
Use the electronic service tool to check the "Active Diagnostic Code" screen. Check for an open circuit diagnostic code. Expected Result:An open circuit diagnostic code for the sensor is now active.Results:
OK - A voltage above normal diagnostic code was active before disconnecting the sensor. An open circuit diagnostic code became active after disconnecting the sensor. Proceed to Test Step 6.
Not OK - There is a short circuit between the sensor harness connector and the ECM. Leave the sensor disconnected. Proceed to Test Step 8.Test Step 5. Measure the Sensor Supply Voltage
Turn the keyswitch to the OFF position.
Disconnect the sensor from the engine harness.
Turn the keyswitch to the ON position.
Measure the voltage from terminal A to terminal B on the sensor connector. Expected Result:The voltage from terminal A to terminal B measures 4.84 to 5.16 Volts DC.Results:
OK - The sensor supply voltage is correct. Proceed to Test Step 7.
Not OK - The sensor supply voltage is out of the nominal range. Continue testing the sensor supply circuit.Repair: Go to Troubleshooting, "5 Volt Sensor Supply Circuit - Test".STOPTest Step 6. Determine if the Short Circuit is in the Connector or in the Sensor
Thoroughly inspect the connector for moisture.
Inspect the seals and reconnect the sensor.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
If the short circuit diagnostic code reappears, the sensor or the sensor connector has a fault.
Temporarily connect a new sensor to the harness but do not install the new sensor in the engine.
Use the electronic service tool to check for a short circuit diagnostic code. The new sensor should be connected to the harness at this time. Expected Result: