3888563 Volvo.Penta Stud

Table 1
Diagnostic Codes Table    
Description     Conditions which Generate this Code     System Response    
336-2 Engine Control Switch erratic, intermittent, or incorrect     The two inputs from the start/run/stop switch are in the opposite state.     The code is logged.    The ADEM box receives a signal from the main junction box that goes to the start/run/stop inputs on the Electronic Control Module (ECM). The signal goes to the terminal strip in the ADEM box. Two separate wires from the terminal strip are wired to two inputs for the start/run/stop switch on the ECM. The signals allow the ECM to determine the status of the "Start" button and the "Kill" button on the control panel.When both of the start/run/stop inputs are connected to the digital return, the ECM determines that the "Start" button is active. The ECM will begin the engine start sequence. When both of the signals are floating, the ECM determines that the "Kill" button is active. If the "Kill" button is active, the ECM shuts down the engine.If the two signals are at a different potential, the ECM will determine that one of the signals is incorrect. A diagnostic code will be logged and a diagnostic code will remain active. The ECM will not begin the starting sequence. If the engine is running and the ECM detects a different potential between the two signals, the ECM will continue to enable injection.The input signals to the ECM are in series with the digital return through a set of normally open contacts of the "Start Deck Engine Relay (SDER)" and through a set of normally closed contacts of the "Fuel Cutoff Relay (FCR)". When the "Start" button on the control panel is activated, the master "DCU" energizes the "Start Deck Engine Relay (SDER)". The normally open contacts of the "Start Deck Engine Relay (SDER)" will close. The ECM will begin the engine start sequence, when the input signals to the ECM are connected to the digital return.When the "Start Deck Engine Relay (SDER)" is de-energized or the "Fuel Cutoff Relay (FCR)" is energized, the start/run/stop inputs to the ECM will float. The ECM will initiate the shutdown sequence.
Illustration 1 g01286693
Typical example
Illustration 2 g01286694
P1 ECM connector (P1-5) Digital return (P1-23) Start/run/stop input 1 (P1-28) Start/run/stop input 2
Illustration 3 g01285750
Location of ECM connectorsTest Step 1. Check for an Active Diagnostic Code
Turn the "main disconnect switch (MDS)" to the ON position.
Start Caterpillar Electronic Technician (ET).
Check for an active 336-2 diagnostic code.Expected Result:The 336-2 diagnostic code is not active.Results:
OK - The 336-2 diagnostic code is not active. Proceed to Test Step 2.
Not OK - The 336-2 diagnostic code is active.Repair: If the diagnostic code 336-2 is active, the start/run/stop inputs between the ECM and the terminal 103 in the ADEM box are in opposite states. Check the wires for an open or for a short circuit.
Check the wires for an open circuit.
Disconnect the J1/P1 ECM connector.
Measure the resistance between P1-21 at ECM connector P1 and terminal 103 on the terminal strip.
Measure the resistance between P1-22 at ECM connector P1 and terminal 103 on the terminal strip.
If the resistance measurement indicates an open circuit, repair the wires and/or connectors between the terminal strip and the ECM.
Check the wires for a short circuit.
Disconnect the J1/P1 ECM connector and the J2/P2 ECM connector.
Disconnect the wire F716-BK and wire F717-BK from terminal 103 in the ADEM box.
Measure the resistance between P1-21 and every terminal on ECM connector P1 and ECM connector P2.
Measure the resistance between P1-21 and engine ground.
Measure the resistance between P1-22 and every terminal on ECM connector P1 and ECM connector P2.
Measure the resistance between P1-22 and engine ground.
If the resistance measurement indicates a short circuit, repair the wires and/or connectors between the terminal strip and the ECM.STOPTest Step 2. Check the Status while the Start/Run/Stop Switch is Active
Observe the status of the start/run/stop switch on Cat ET.
Turn the start/run/stop switch to the START/RUN position.Expected Result:The status for the start/run/stop switch reads "START".Results:
OK - The status for the start/run/stop switch reads "START". Proceed to Test Step 3.
Not OK - The status for the start/run/stop switch does not display "START". Proceed to Test Step 4.Test Step 3. Check the Status while the Start/Run/Stop Switch is Not Active
Turn the start/run/stop switch to the STOP position.
Observe the status of the start/run/stop switch on Cat ET.Expected Result:The status for the start/run/stop switch reads "STOP".Results:
OK - The status for the start/run/stop switch reads "STOP".Repair: The start/run/stop switch is functioning correctly. There may be an intermittent problem. If the problem is intermittent, refer to Troubleshooting, "Inspecting Electrical Connectors".STOP
Not OK - The status for the start/run/stop switch does not read "STOP". Proceed to Test Step 6.Test Step 4. Check the Signal for the Start/Run/Stop Switch in the ADEM Box for an Open Circuit
Turn the "MDS" to the OFF position.
Disconnect the wire from the main junction box that is on terminal 101 in the ADEM box.
Disconnect the wire from the main junction box that is on terminal 103 in the ADEM box.
Turn the "MDS" to the ON