924090 Volvo.Penta Stud

Table 1
Diagnostic Trouble Codes for the Engine Speed/Timing Sensors
J1939 Code Description Notes
190-8 Engine Speed : Abnormal Frequency, Pulse Width, or Period The Electronic Control Module (ECM) detects the following conditions:
The signal from both the primary and secondary speed sensors is greater than 4000 rpm for at least 2 seconds.
The keyswitch is on for at least 2 seconds.
The engine is running.
The warning lamp will flash and the shutdown lamp will come on.
The engine will be derated and the engine may shut down.
723-3 Engine Speed Sensor #2 : Voltage Above Normal The ECM detects the following conditions:
The signal from the secondary speed sensor is less than 100 rpm for at least 5 seconds.
The signal from the primary speed sensor is in range.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated.
723-4 Engine Speed Sensor #2 : Voltage Below Normal The ECM detects the following conditions
The signal from the secondary speed sensor is greater than 4000 rpm for at least 5 seconds.
The signal from the primary speed sensor is in range.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated.
723-8 Engine Speed Sensor #2 : Abnormal Frequency, Pulse Width or Period The ECM detects the following conditions:
The signal from the primary speed sensor is less than 100 rpm for at least 0.1 second.
The signal from the secondary speed sensor is greater than 4000 rpm for at least 0.1 second.
The keyswitch is ON for at least 2 seconds.
The warning lamp will flash and the shutdown lamp will come on.
The engine will be derated and the engine may shut down.
723-10 Engine Speed Sensor #2 : Abnormal Rate of Change The ECM detects the following conditions:
The difference between the speed signals from the primary and secondary speed sensors is greater than 20 rpm for at least 5 seconds.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated.
4201-3 Engine Speed Sensor #1 : Voltage Above Normal The ECM detects the following conditions:
The signal from the primary speed sensor is less than 100 rpm.
The signal from the secondary speed sensor is in range.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated.
4201-4 Engine Speed Sensor #1 : Voltage Below Normal The ECM detects the following conditions:
The signal from the primary speed sensor is greater than 4000 rpm.
The signal from the secondary speed sensor is in range.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated.
4201-8 Engine Speed Sensor #1 : Abnormal Frequency, Pulse Width, or Period The ECM detects the following conditions:
The signal from the secondary speed sensor is less than 100 rpm.
The signal from the primary speed sensor is greater than 4000 rpm.
The keyswitch is ON for at least 2 seconds.
The warning lamp will flash and the shutdown lamp will come on.
The engine will be derated and the engine may shut down.
4201-10 Engine Speed Sensor #1 : Abnormal Rate of Change The ECM detects the following conditions:
The difference between the speed signals from the primary and secondary speed sensors is greater than 20 rpm.
The keyswitch is ON for at least 2 seconds.
The engine is running.
The warning lamp will flash.
The engine will be derated. The engine uses two engine speed sensors. The primary speed sensor is located on the left-hand side of the front housing. The primary speed sensor generates a signal by detecting the movement of the teeth that are located on the crankshaft gear. The signal that is generated by the speed sensor is transmitted to the ECM. The ECM uses the signal from the speed sensor to calculate the engine speed. The secondary speed sensor is located in the right of the front cover. The secondary speed sensor generates a signal that is related to the camshaft speed. The secondary speed sensor detects the movement of the camshaft gear. The signal that is generated by the speed sensor is transmitted to the ECM. The ECM calculates the speed of the engine by using the signal.The loss of signal to the primary sensor and/or the secondary sensor will result in one of the following faults:
The engine will be derated when only one sensor signal is present from either the primary sensor or the secondary sensor.
Loss of signal from the primary sensor and the secondary sensor during operation of the engine will cause the engine to be shut down.Pull-up VoltageThe ECM continuously outputs a pull-up voltage on the circuit for the primary and secondary speed sensor signal wire. This pull-up voltage is required for correct sensor operation and diagnostics.
Illustration 1 g03259316
Schematic for the speed sensors
Illustration 2 g03259416
View of the pin locations for the speed sensors on the P2 connector
(8) Primary speed sensor ground
(9) Primary speed sensor signal
(10) Primary speed sensor 5 VDC supply
(11) Secondary speed sensor 5 VDC supply
(12) Secondary speed sensor signal
(13) Secondary speed sensor ground
Illustration 3 g03259421
Typical example of speed sensor
(1) Speed sensor 5 VDC supply
(2) Speed sensor ground
(3) Speed sensor signal Test Step 1. Inspect the Electrical Connectors and the Harness
Turn the keyswitch to the OFF position.
Inspect the connectors for the speed sensors. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the suspect sensor connector and the sensor connections at the ECM.
Check the harness for abrasion and pinch points from the suspect sensor to the ECM.
Check that the suspect sensor is installed correctly. Check that the suspect sensor is fully seated into the engine. Check that the sensor is securely latched. Expected Result:The electrical connectors and the cables are correctly installed.Results:
The harness is OK. - Proceed to Test Step 2.
Not OK - Repair: Repair the faulty connectors or the harness and/or replace the faulty connectors or the harness. Ensure that all of the seals are correctly in place and ensure that the connectors are correctly coupled.If the primary speed sensor must be replaced