Sea temp ckt Hi. Port message

[tawcat]

Running 6.2 v drives in a 320. This message pops up at start up, engines are running fine and temps are around 155, where they should be.

Any ideas?

 

[CJ Martin]

Sensor or a loose connection to a sensor? Just a guess.

-CJ

 

[tawcat]

CJ any idea where the sensor is located?
Thanks.

 

[CJ Martin]

I don't know where the sensor is - the Merc #33 manual is for 555 PCM Diagnostics, but the wiring diagrams are for the 496 (8.1L) big block. However I am willing to be the fault troubleshooting is the same - here's what the #33 manual has for your fault:

1. Cool TMP CKT Hi or Lo

1.0 Open(Hi) or Short (Lo) in harness wiring, faulty connection

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1.0 Repair harness connection or cut in wire.

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1.1 Open(Hi) or Short (Lo) sensor

1.1 Replace sensor. ​

1.2 Water in the connector ​

1.2 Dry connector and inspect for cracks or wear. Replace.

Since a Hi fault is caused by an open, I strongly suspect a broken wire or a loose / dirty connection.

My hard copy #31 manual (5.7L) is on the boat - it may show the sensor location and I'll try to remember to look when I'm over there tomorrow. It can't be too hard to find - it has to be a sensor in the seawater side of the cooling loop. Follow the hoses from the thru-hull and you should find it.

-CJ​

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[tawcat]

Thanks, gonna check it tomorrow, will let you know.

 

[Fun Times]

Running 6.2 v drives in a 320. This message pops up at start up, engines are running fine and temps are around 155, where they should be.

Any ideas?

The sea temp would be for reading the water temp of the body of water your are boating in.

Are you normally able to read the water temp on that gauge in the past? If so then you may have a bad sea temp sensor. Normally the sensor would be the depth gauge transducer. If not, some boats do not have this option installed and you would normally just ignore this fault if you where looking at a MPI scan tool. The PCM is designed to kind of ignore it also to where it will not put the engine in guardian mode if/when it fails.

If you do not have this option, Then you may need to reset the gauge to clear it out.

http://www.offshoreonly.com/forums/...des-vs-rinda-94050m-mercruiser-scan-tool.html

http://www.veradoclub.com/docs/vvmp2p-2.pdf

 

[tawcat]

Thanks so much for the help. Hate that the guy that bought our boat is experiencing these things first weekend out.

 

[tawcat]

Just wanted to provide a follow up to your help.

So he asked if I'd come to the boat this morning and go over all the stuff with him. No problem, my concern is him thinking we sold them a lemon. Not the case.

So we show up, I open the engine hatch and point out sea cocks etc. I check strainers on both sea cocks, little debris in one, other is clean. I check the wiring to the sensors. To my surprise one wire pulls loose. No tools, so I explain what he needs to do. In the mean time I push the loose wire into the connector, give a twist to make sure it is secure.

We start engines, no warnings. Voila'

I check out the other issues and all seems fine and he is satisfied.

So once again CSR comes through with flying colors. Thank you, thank you, thank you.