Originally Posted by webie
I just checked near by hoses and they seam to be OK. I don’t have a OBD-2 MAP Tool. But the Honda Accord (98-00) Service Manual states that code (5) could be “MAP Sensor Lower than Expected (P1128)” or “Sensor Higher than Expected (P1128)” and to check for MAP failure it requires me the MAP Tool to check for specific parameters. I just called Honda and they told me the will charge $75 to check OBD-2 which will be deducted if I do the job with them; and we don’t have AutoZone here in PR. The part with tem costs $115 and they charge $85/hr with a minimum charge of ˝ hour. So that will bring the total cost to about $160.00 for the repair when I could do it myself for about half the price and learn in the process. I could check the circuit voltage but Honda has another specific code (3) for that problem “MAP Circuit Low Voltage”.
So, is there is any other way to check for MAP Sensor failure. Let’s say by checking the it's resistance between two contacts or by plugging it out and look at it? I don't want to spend $80 bucks for the MAP and the realize it was not the MAP.
On thing I haven't done yet, is trying to "reset" the "ECM" to see if the problem disappears. I have difficult time doing that since it will reset my Alpine radio in which I have spent some time setting radio stations and CD names.
Also this is probably out of topic but… Can you recommend a OBD-2 reader preferably one that I could connect to my laptop/computer. I know the Honda Scan Tool could cost from between 2K (Small) – 7k (Tablet PC Based; and that’s way too much for me. But on the WEB there are so many custom made models ranging from $100 - $300
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UPDATE: I just "reset" the "ECM" and the CEL is now off. Do you think this could be an intermittent problem? Or maybe after cleaning connections and mount/dismount near by hoses, the problem is solved? If the malfunction occurs again will the CEL light up again or I just fully reset it for that problem?
well what that means by lower than expected is that the computer is getting information from the map and it thinks is incorrect based on the on other sensors input. Like the computer knows what map should be for any given condition based off other big sensors like tps, crank sensor. It kinda cross references against the other sensors to make sure nothings out of range. OBD2 cars give more information than the obd1 cars. Obd1 cars would only know a problem existed if the circuit for a sensor was open or shorted. That's it. I've seen obd1 cars with bad O2 sensors that never throw codes.
Obd2 has the same logic above as obd1 plus it has the logic that "knows" when a sensor isn't giving a good input. It knows say that at 50mph and 2300 rpm what the map should be like. It's throwing a code and saying hey that reading isn't making sense then it ignores it and gets a value from a look up table in the computers logic circuit. So, what I said before will give you an answer. You don't need the fancy pants tool, use the tool in your head get a cheapo meter and back probe the connector. If at idle it's like .5v replace it.
Oh yeah and just because it doesn't come right back doesn't mean anything. It probably has a temp. code stored ready to throw on the light if it sees it again. It will most likely come back.