Engine Room Discussions

[macmech12]

I have a problem with a 3508B Main Propulsion Engine on my Vessel; It was working fine then I sprang a Coolant leak and it sprayed all over the engine room.  I took care of the coolant leak and got everything all cleaned up.  I went to start the engine and it will no longer start and I am throwing the 336-2 Code now, So I went ahead and replaced the rotary switch thinking that would take care of things but nothing.  Both control stations are working properly and it will crank and run when I do the manual crank once opening up the panel in the engine room.  Any ideas?  Is the primary ECM possibly shorted out in the starting circuit from the coolant leak spraying all over it?  Anything you can pass along would be greatly appreciated.

Thanks

[BlackCat1]

Since you said it will start from the local panel, the ECM is not shorted. Here is a description of the start function.  You will need a schematic to troubleshoot.

The primary electronic control module (ECM) receives three signals that allow the ECM to determine the mode of operation. The input signals on P1-21 and P1-22 tell the ECM the position of the ECS. The input signals on P1-21 and P1-22 must be at the same potential or a diagnostic code will be generated. The third input signal on P1-68 tells the ECM if the ECS is in the REMOTE position. If the input signal on P1-68 is low, the ECM knows that the ECS is in the REMOTE position. If the input signal on P1-68 is not low, the ECM knows that the ECS is not in the REMOTE position.

When the ECS is in the REMOTE position, inputs from the customer control the operation of the engine. The following list contains some of the inputs from the customer connector and the inputs function.

• C remote start 2
• D remote start 1
• E remote stop 1
• F remote stop 2
• S "ECS (remote/auto)"
• c keyswitch

When the ECS is in the REMOTE position, the "Remote Start" relay and the "Remote Stop" relay are energized. When the remote start inputs C and D go low, the following relays energize: "Run 1" relay, "Run 2" relay, "Reset 1" relay and "Reset 2" relay. The start/run/stop inputs P1-21 and P1-22 will be pulled low. The engine will begin the start cycle. When the customer's remote stop inputs F and E are low, the following relays energize: "Stop 1" relay and "Stop 2" relay. The start/run/stop inputs P1-21 and P1-22 will be high. The engine will begin the stop function. When the ECS is in the REMOTE position, the "ECS in Remote" relay energizes. The "ECS in Remote" relay sends a signal to the customer connector that allows the customer to determine the position of the ECS.

When the ECS is in the START position, the following relays energize: "Run 1" relay, "Run 2" relay, "Reset 1" relay and "Reset 2" relay. The start/run/stop inputs P1-21 and P1-22 will be pulled low. The engine will begin the start cycle.

When the ECS is in the STOP position, the following relays energize: "Stop 1" relay and "Stop 2" relay. The start/run/stop inputs P1-21 and P1-22 will be high.

When the ECS is in the OFF/RESET position, none of the relays are energized.

[macmech12]

Sounds good, I will def have to check that out in the morning.  I am starting to wonder if the problem is up at the remote switch up in the bridge.  I am going to check that out tomorrow.  Some how have a feeling that might be the culprit, cause after your explanation if something came disconnected up in the pilot house it could throw off everything.  But still wouldnt explain why she doesn't go through her startup routine and actually start when I turn her to manual start down at the local panel.  I have to physically open the panel up and use the manual crank toggle switch.

[macmech12]

But in the morning I will pull out the wiring diagram and go through the whole thing. Hopefully find out what is going on...  Miss working on old engines.