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03 Merc 43 MPI unknown alarm

garager

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"My 03 Trophy 4.3 MPI recently

"My 03 Trophy 4.3 MPI recently started the 2 beeps every 60 seconds. Engine oil level and temp are fine. Gear lube bottle is full w/correct (quicksilver) lube. Disconnecting the sensor on top of motor (I believe that's the MAP), causes three beeps when key is turned on but 2 beeps every min. remain. Engine seems to run fine. Have heard talk of AIT(air intake temp.)sensor being a cause,but dealer says that description doesn't exist in their computer. Is there such a sensor, if so, where is it? Can anybody help?"
 
The air inlet temp should be p

The air inlet temp should be part of the absolute pressure sensor. All one device.
Your dealer ought to be able to hook up their diagnostic tool and see what if any codes are stored in your ECM.
That should make it easy to troubleshoot.

Rod
 
"The MAT and MAP sensors are t

"The MAT and MAP sensors are two different sensors, not one, and each can set an alarm.

In fact, there are at least 26 things that will set a "soft" alarm (two beeps per minute), and as suggested, connecting a scan tool will tell you what is causing the alarm. My guess would be IAC failure, it's very common.

Dave"
 
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