844486 Volvo.Penta Timer relay

Illustration 1 g00745644
Schematic for the R2900GTest Step 1. Inspect Electrical Connectors and Wiring
Turn the keyswitch to the OFF/RESET position.
Thoroughly inspect ECM connector J1/P1, engine speed/timing sensor connector J20/P20, and engine speed/timing sensor connector J44/P44. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
Check the harness and wiring for abrasion and pinch points from the engine speed/timing sensors to the ECM.Expected Result:All connectors, pins, and sockets should be completely inserted and coupled. The harness and wiring should be free of corrosion, abrasion, and pinch points.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the circuit. Verify that the repair eliminates the problem. Stop.Test Step 2. Check for Diagnostic Codes
Connect an electronic service tool to the service tool connector.
Turn the keyswitch to the ON position.
Observe Logged Diagnostic Codes on the electronic service tool.Expected Result:The electronic service tool should indicate one of the following diagnostic codes as being active or recently logged:
190-02 (Loss of Engine RPM Signal)
190-08 (Engine Speed Signal abnormal)
342-02 (Loss of Backup Engine RPM Signal)
342-08 (Backup Engine Speed Signal abnormal)Results:
OK - One of the above diagnostic codes is active or recently logged.Repair: If 190-02 (Loss of Engine RPM Signal) and/or 190-08 (Engine Speed Signal abnormal) is present, disconnect the secondary engine speed/timing sensor.If 342-02 (Loss of Backup Engine RPM Signal) and/or 342-08 (Backup Engine Speed Signal abnormal) is present, disconnect the primary engine speed/timing sensor. Proceed to Test Step 3.
Not OK - Neither of the above diagnostic codes is active or recently logged. Proceed to Test Step 3.Test Step 3. Check the Engine Speed/Timing Sensor
Turn the keyswitch to the OFF/RESET position.
The flange of the sensor should be flush against the engine in order to ensure proper operation.
Inspect the bracket in order to ensure that the installation allows the flange of the sensor to be flush against the engine.Verify that the bracket is not bent.Note: The bracket cannot be replaced separately.
Ensure that the O-ring has been installed on the sensor, and ensure that the O-ring is free of damage.Expected Result:The flange of the sensor should be flush against the engine in order to ensure proper orientation. The sensor mounting bracket should not be bent.Results:
OK - The engine speed/timing sensor is seated properly and the bracket is not bent. Proceed to Test Step 4.
Not OK - The engine speed/timing sensor is not seated properly or the bracket is bent.Repair: Perform the following procedure in order to properly install the sensors and the bracket:
Loosen the bolt that holds the sensor mounting bracket to the engine.
Seat the sensor and tighten the bolt.If the sensor will not seat, repair the sensor or replace the sensor, as required.Note: The sensor must not be removed from the bracket.
Ensure that the sensor is properly oriented and that the harness is secured in the proper location.
Verify that the repair eliminates the problem. Stop.Test Step 4. Check Engine Speed on an Electronic Service Tool
Turn the keyswitch to the ON position and crank the engine.
Observe the engine speed on the electronic service tool while you crank the engine.Expected Result:The electronic service tool should display a steady engine speed between 100 and 250 rpm while the engine is cranking and the engine should start.Results:
OK - The engine speed/timing sensor is operating normally at this time.Repair: Reconnect the known good engine speed/timing sensor.If you are troubleshooting an intermittent problem, refer to Troubleshooting, "Electrical Connectors - Inspect". Stop.
No Engine Speed - The engine does not start and the engine speed does not appear on the electronic service tool. Proceed to Test Step 5.
Engine Speed OK/Engine Will Not Start - The engine will not start. Engine speed appears on the electronic service tool.Repair: Reconnect the known good engine speed/timing sensor.Proceed to Troubleshooting, "Engine Cranks But Will Not Start". Stop.Test Step 5. Check for a Short Circuit in the Wiring Harness
Turn the keyswitch to the OFF/RESET position.
Disconnect ECM connector J1/P1 and the connector on the suspect engine speed/timing sensor.
Measure the following resistances at the connector on the suspect engine speed/timing sensor (harness side).
Terminal 1 (Speed/Timing -) and Terminal 2 (Speed/Timing +)
Terminal 1 (Speed/Timing -) and engine ground
Terminal 2 (Speed/Timing +) and engine groundExpected Result:The resistance should be greater than 20,000 Ohms for each measurement.Results:
OK - Proceed to Test Step 6.
Not OK - There is a short circuit in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 6. Check the Resistance through the Harness
Illustration 2 g00754948
ECM connector P2 (ECM side)
Illustration 3 g00754209
ECM connector P1 (ECM side)
Fabricate a jumper wire with pins at both ends.
Use the jumper wire to short P2:4 (Secondary Speed/Timing -) and P2:39 (Secondary Speed/Timing +) together.
Measure the resistance between J20:1 (Secondary Speed/Timing -) and J20:2 (Secondary Speed/Timing +).
Use the jumper wire to short P1:12 (Primary Speed/Timing -) and P1:18 (Primary Speed/Timing +).
Measure the resistance between J44:1 (Primary Speed/Timing -) and J44:2 (Primary Speed/Timing +).
Remove the jumper wire and reconnect all of the connectors.Expected Result:The resistance should read less than 10 Ohms when the jumper wire is installed.Results:
OK - The harness resistance is within acceptable limits. Proceed to Test Step 7.
Not OK - There is an open circuit or excessive resistance in the harness or connectors.Repair: Repair the circuit.Verify that the repair eliminates the problem. Stop.Test Step 7. Measure The Resistance Of The Sensor At The Sensor.
Turn the keyswitch to the OFF position.
Check the harness and the wiring for abrasion and pinch points from the sensor back to the ECM.
Disconnect the suspect sensor from the engine harness.
Thoroughly inspect ECM engine harness connectors for the sensors J20/P20 or J44/P44. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.