7742140_123 Volvo.Penta reduction gear

Table 1
Diagnostic Codes Table    
Description    Conditions which Generate this Code    System Response    
158-2 Keyswitch Battery Potential : Erratic, Intermittent, or Incorrect     The Electronic Control Module (ECM) has detected three transitions of the signal for the keyswitch within one second.     The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
The ECM is latched.    
168-2 Battery Potential / Power Input 1 : Erratic, Intermittent, or Incorrect     The input voltage to the ECM has dropped below 6 v and the input voltage has risen above 9 v three times within 7 seconds.     The code is logged.
The amber warning lamp is illuminated.    
168-3 Battery Potential / Power Input 1 : Voltage Above Normal     The input voltage to the ECM has risen above 32 v for one second.     The code is logged.
The amber warning lamp is illuminated.
The ECM will use default values for all of the engine sensors that are powered.
The status of the "Battery Voltage" parameter is reported as "Data Error" by Caterpillar Electronic Technician (ET).    
168-4 Battery Potential / Power Input 1 : Voltage Below Normal     The input voltage to the ECM has dropped below 18 v for one second.     The code is logged.
The red stop lamp is illuminated.
The engine is shut down.
The ECM will use default values for all of the engine sensors that are powered.
The status of the "Battery Voltage" parameter is reported as "Data Error" by Cat ET.    
3542-3 Requested Engine Control Mode : Voltage Above Normal     The ECM has detected a simultaneous open circuit condition for the engine stop circuit and the start circuit for at least 2 seconds.     The code is logged.
The red stop lamp is illuminated.
The engine is shut down.    
3542-4 Requested Engine Control Mode : Voltage Below Normal     The ECM has detected the simultaneous grounding of the engine stop circuit and the start circuit for at least 2 seconds.     The code is logged.
The red stop lamp is illuminated.
The engine is shut down.    Electrical power from the batteries is supplied to the following components:
Electronic Control Module (ECM)
Engine Control Switch (ECS)
Fuel actuator
Messenger
Throttle actuator
Voltage converterThese components are electrically protected by two circuit breakers that are located at the breaker panel. The breaker panel is mounted to the right side of the engine.The cause of an intermittent problem with the power supply can occur on either the positive side or the negative side of the power supply.The engine ECM receives keyswitch power from the engine control switch. Terminal location P1-40 is used for this purpose. Keyswitch power is available at this terminal location when the engine control switch is in the RUN position and in the STOP position. When the engine ECM detects battery voltage at the keyswitch input, the ECM will power up. When battery voltage is removed from this input, the ECM will power down.Note: If replacement of the engine control switch is necessary, be sure to use replacement parts that have been approved by Caterpillar. The use of aftermarket parts may cause adverse conditions during starting and/or engine operation.The ECM, the fuel actuator, and the throttle receive power from an unswitched battery circuit via dedicated breakers at the breaker panel.A digital return at terminal location P1-35 is used as a ground source by the engine control switch. The position of the switch is reported to the ECM via terminal locations P1-50 and P1-51. The engine control switch provides a ground path to the appropriate terminal location as the position of the engine control switch is changed. The ECM input circuitry monitors the position of the engine control switch by detecting the ground source at these terminal locations. This information is used by the ECM for the engine state control.The most likely problem with the electrical power supply is probably caused by a problem with the batteries. The next likely cause is a problem in the harness or in a connector. The least likely cause is a problem with the ECM.
Illustration 1 g03749265
Schematic for the electrical power supply
Illustration 2 g01969943
Locations of the components for the electrical power supply (typical left side engine view) (1) Display panel (2) Breaker panel (3) ECM
Illustration 3 g01970015
Locations of the components at the ECM panel that are associated with the electrical power supply (typical left front engine view) (4) J1/P1 ECM connectors (5) Harness connector for the breaker panel (6) Interconnect harness connector
Illustration 4 g01970074
Locations of the circuit breakers (typical right side engine view) (7) Circuit breaker for the ECM (15 amp) (8) Circuit breaker for the auxiliary circuit (20 amp) (9) Circuit breaker for the starting system (40 amp) (10) Circuit breaker for the alternator (40 amp)
Illustration 5 g01970754
Terminal locations at the P1 ECM connector that are for the electrical power supply (P1-1) -Battery (P1-2) -Battery (P1-3) -Battery (P1-7) +Battery (P1-8) +Battery (P1-9) -Battery (P1-10) -Battery (P1-15) +Battery (P1-16) +Battery (P1-35) Digital return (P1-40) Keyswitch (P1-50) Stop mode (P1-51) Run mode
Illustration 6 g01970796
Terminal locations at the interconnect harness connector that are for the electrical power supply (Terminal h) Stop mode (Terminal r) Digital return (Terminal w) Keyswitch (Terminal x) -Battery (Terminal z) +Battery (Terminal O) Run Mode