Engine/Transmission (1998.5 - 2002) Anatomy of the Map Sensor?

[GOTSOOT]

Can someone give me a quick synopsis of the inner workings of a map sensor. Seems to me that there ought to be a way to circumvent this item with something. My thinking is that it works off of a diaphram with connections on the back side that make contact with the pins in the plug?

 

[Bobalos]

I have been doing some testing on it & it looks to me like its simply a Solid State presure transducer. it takes +5 V in & a ground signal & gives you a linear output for a given pressure.



Lbs---Gauge1---Gauge2---Calc Pres

0------. 502------. 505------. 500

5------. 889------1. 045-----. 900

10-----1. 283-----1. 460-----1. 300

15-----1. 682-----1. 868-----1. 700

20-----2. 095-----2. 265-----2. 100

25-----2. 503-----2. 660-----2. 500

30-----2. 905-----3. 070-----2. 900

35-----3. 220-----3. 500-----3. 300

40-----3. 640-----3. 830-----3. 700

45-----4. 040-----4. 210-----4. 100

50-----4. 440-----xxxxxx----4. 500

55-----4. 850-----xxxxxx----4. 900

60-----4. 850-----xxxxxx----xxxxx



I had 2 gauges, neither of which really were the right range for this test, but you can see that one was pretty close to what I calculated should have been the right voltages.



Bob

 

[Bobalos]

Im not sure what your goals are, I can only guess that you have increased the boost & are now getting over boost codes??? if that is the case, then yes, there are ways to get around it. IMO, the "best" way would be a box that tricks the ECM into thinking that the boost does not go too high, but there is a brute force way, with a diode that will clamp the signal so it does not get too hi. there are plenty of folks that sell boxes that will trick the ECM into thinking that the boost is not getting too high & I am pretty sure thet there are also folks out there that sell zener diodes that you can splice in that will clamp it @ about 2. 00 volts.



Bob

 

[Bobalos]

I would like to know if anyone else out there can confirm that this is in fact a 50 Lb gauge, & that my data is right.



Bob

 

[NoSeeUm]

I would like to know if anyone else out there can confirm that this is in fact a 50 Lb gauge, & that my data is right.



Bob

My TST uses the MAP pressure transducer to display boost. For some time I had thought it only went to just over 40 psi. But the other day a friend rode with me and said he saw it in the mid 50 psi range. So with that information I am guessing you might be about right.



Jim

 

[Bobalos]

thanks amigo. I think I am going to buy a better gauge & double check it, but it makes sense, with that first gauge.



Bob