2004 V70 (non tur) Check Engine Light - Code ECM100A

[Tennisplyr]

I got this letter in the mail from Volvo about the extension of the warranty up to 120,000 miles or 10 years for P46 Extended Warranty. Well, my check engine light has been on so I took it to the dealer today. They said they didn't find anything wrong with the items listed in the letter (1. Evaporative Emissions System, 2. Fuel System Control, Oxygen Sensor, 3. Fuel System Control, Mass Air Flow Sensor).

But they did say the the check engine light code found: EMC100A engine control module. Completed a test for atmospheric pressure sensor and MAP and the reading is too high.

They quoted me $1800 for parts and labor.
First, what is this ECM 100A??? Anyone know??
Do I need to have this done??? Help!

[VCA]

I got this letter in the mail from Volvo about the extension of the warranty up to 120,000 miles or 10 years for P46 Extended Warranty. Well, my check engine light has been on so I took it to the dealer today. They said they didn't find anything wrong with the items listed in the letter (1. Evaporative Emissions System, 2. Fuel System Control, Oxygen Sensor, 3. Fuel System Control, Mass Air Flow Sensor).

But they did say the the check engine light code found: EMC100A engine control module. Completed a test for atmospheric pressure sensor and MAP and the reading is too high.

They quoted me $1800 for parts and labor.
First, what is this ECM 100A??? Anyone know??
Do I need to have this done??? Help!

ECM-100A means that the ECM registered a difference greater than 70 hPa (1.01 psi) between the MAP sensor and the atmospheric sensor. There are two possible causes: bad MAP sensor, or bad ECM (the atmospheric sensor is onboard the ECM). Since ECM-1000 hasn't been stored (has it?) we should assume the MAP is bad and replace it first. Not sure what they are going to replace for $1,800--sounds like that's the ECM, a MAP sensor won't run you $1,800.