3 beeps intermittent

[DavidMelvin]

I have a 2004 Malibu 21 lsv with 385 hours. I am getting a beep, beep, beep after about a minute of start-up. It continues at idle and slow speeds. When I go over 3000 rpm, it becomes a steady, consistent, beep. The only thing  that shows up on the gauges is that the temperature never comes up to operating temp and when you turn off the ignition, the depth gauge reads "BAD". Any ideas?

[electricjohn]

May be code 33 which is faulty MAP sensor.

[csleaver]

There are no onboard ECM diagnostics available on a 2004 Malibu, so a MEFI code reader or diagnostic software like Diacom are needed to see if there are diagnostic trouble codes causing the alarm or not.  Without that, you are forced to check for sensor outputs from the ECT, oil pressure, MAP, TPS, injector drivers, and so on with a volt ohm meter against the actual coolant temperature, oil pressure, and so on.  The diagnostic software and code readers are just another tool to help find problems more easily, like using a power drill and stud finder instead of a hammer and a screwdriver to hang a shelf.