839128 Volvo.Penta Plastic plug

Illustration 1 g01983794
Schematic for air ambient temperature sensor
Illustration 2 g01983795
Air ambient temperature sensor connector
(A) Sensor +5 Volt supply
(B) Sensor return
(C) Sensor signal
Illustration 3 g01983796
A typical view of the P1 connector (harness side) pin locations.
(33) Sensor return
(41) Sensor +5 Volt supply
(56) Sensor signal Test Step 1. Inspect Electrical Connectors And Wiring
Remove the electrical power from the ECM.
Thoroughly inspect the ECM engine harness connector and the connector for the air ambient temperature sensor. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires that are associated with the air ambient temperature sensor.
Verify that the latch tab of the connector is correctly latched.
Check the allen head screws for each ECM connector for the proper torque. Refer to Troubleshooting, "Electrical Connectors - Inspect" for the correct torque values.
Check the harness for abrasions, for pinch points, and for corrosion. Expected Result:All connectors, pins, and sockets are completely coupled and/or inserted. The harness is free of corrosion, of abrasion, and of pinch points.Results:
OK - The connectors and wiring appear to be OK. Proceed to Test Step 2.
Not OK - There is a fault 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 correctly installed and ensure that the connectors are completely coupled.If necessary, perform the "Wiggle Test" on the electronic service tool.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check the Supply Voltage at the Sensor Connector
Remove the electrical power from the ECM.
Disconnect the harness connector for the air ambient temperature sensor.
Restore the electrical power to the ECM.
Measure the voltage between terminals A (+5 Volts DC) and B (Return) at the sensor connector on the engine harness.
Remove the electrical power from the ECM.
Reconnect the sensor. Expected Result:The voltage measurement is 5.0 0.2 Volts DC.Results:
OK - The voltage measurement is 5.0 0.2 Volts DC. Proceed to Test Step 3.
Not OK - The voltage measurement is not 5.0 0.20 Volts DC.Repair: The correct voltage is not reaching the sensor. Refer to Troubleshooting, "Analog Sensor Supply Circuit - Test".STOPTest Step 3. Check for Active and/or Logged Diagnostic Codes
Connect the electronic service tool to the diagnostic connector.
Restore the electrical power to the ECM.
Monitor the active diagnostic code screen on the electronic service tool. Check and record any active diagnostic codes. Note: Wait at least 30 seconds in order for the diagnostic codes to become active.Note: A diagnostic code that is logged several times is an indication of an intermittent problem. Most intermittent problems are the result of a poor connection between a socket and a pin in a connector or of a poor connection between a wire and a terminal.
Look for a 171-3 diagnostic code or a 171-4 diagnostic code. Expected Result:No diagnostic codes are active.Results:
OK - No diagnostic codes are active. The problem appears to be resolved.Repair: The problem may have been intermittent. Carefully reinspect the connectors and wiring. Refer to Troubleshooting, "Electrical Connectors - Inspect".STOP
Not OK - A 171-4 diagnostic code is active at this time. Proceed to Test Step 4.
Not OK - A 171-3 diagnostic code is active at this time. Proceed to Test Step 5.Test Step 4. Disconnect the Sensor in Order to Create an Open Circuit
Remove the electrical power from the ECM.
Disconnect the sensor from the engine harness.
Restore the electrical power to the ECM. Wait at least 30 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Codes" screen on the electronic service tool and check for an active 171-3 diagnostic code for the suspect sensor.
Remove the electrical power from the ECM. Expected Result:A 171-3 diagnostic code is now active for the sensor.Results:
OK - A 171-4 diagnostic code was active before disconnecting the sensor. A 171-3 diagnostic code became active after the sensor was disconnected. There may be a problem with the sensor.Repair: Temporarily connect a new sensor to the harness, but do not install the new sensor in the engine. Use the electronic service tool in order to verify that the repair eliminates the fault. If there are no active diagnostic codes for the sensor, permanently install the new sensor.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOP
Not OK - The 171-4 diagnostic code is still present. Leave the sensor disconnected. Proceed to Test Step 7.Test Step 5. Check the Signal Wire for a Short Circuit
Remove the electrical power from the ECM.
Disconnect the P1 ECM connector.
Disconnect the harness connector for the ambient air temperature sensor.
Measure the resistance between terminal P1-56 and the remaining terminals on the ECM connector.
Connect the P1 ECM connector. Connect the connector for the air ambient temperature sensor. Expected Result:Each resistance measurement indicates an open circuit.Results:
OK - Each resistance measurement indicates an open circuit. Proceed to Test Step 6.
Not OK - At least one resistance measurement does not indicate an open circuit.Repair: There is a short circuit in the harness. Repair the harness or replace the harness.If necessary, perform the "Wiggle Test" on the electronic service tool.Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 6. Create a Short at the Sensor Connector
Disconnect the ambient air temperature sensor at the sensor connector.
Fabricate a jumper wire that can be used to create a short between terminal A (signal) and terminal B (sensor return) at the connector for the ambient air temperature sensor. Crimp connector pins to each end of the jumper wire.
Install the jumper onto the harness side of the sensor connector.
Restore the electrical power to the ECM. Wait at least 30 seconds for activation of the diagnostic codes.
Access the "Active Diagnostic Code" screen on the electronic service tool. Check for an active 171-4 diagnostic code for the ambient air temperature sensor.
Remove the electrical