measurement is in absolute kPa or gauge kPa. Typically, this is done by writing “kPa, abs” for the former,
and “kPa, gauge” for the latter. For the purposes of this section, we will treat all kPa reading as
absolute
readings.
Table G.1.1
gives conversion data for US and metric units. Remember:
Ambient (atmospheric) Pr Gauge Pressure = Absolute Pressure
•
1psi = 6.895 kPa
•
1 in-Hg = 3.377 kPa
•
1 Bar = 101.3kPa, abs = 0psi, gauge
•
2 Bar = 202.6kPa, abs = 14.7psi, gauge
•
3 Bar = 303.9kPa, abs = 29.4psi, gauge
Table G.1.1:
US to metric unit conversion data.
kPa
Absolute
in-Hg/psig
Gauge
kPa
Absolute
in-Hg/psig
Gauge
0
29.9 in-Hg
170
10.0 psi
10
27.0 in-Hg
180
11.4 psi
20
24.0 in-Hg
190
12.9 psi
30
21.1 in-Hg
200
14.3 psi
40
18.1 in-Hg
210
15.8 psi
50
15.2 in-Hg
220
17.2 psi
60
12.2 in-Hg
230
18.6 psi
70
9.28 in-Hg
240
20.1 psi
80
6.31 in-Hg
250
21.6 psi
90
3.35 in-Hg
260
23.0 psi
100
0.39 in-Hg
270
24.4 psi
110
1.26 psi
280
25.9 psi
120
2.71 psi
290
27.4 psi
130
4.16 psi
300
28.8 psi
140
5.61 psi
310
30.3 psi
150
7.06 psi
320
31.7 psi
160
8.51 psi
330
33.2 psi
MAP Sensor Data
To check that the MAP sensor is working correctly, and to check for the MAP sensor Bar number
(1-, 2-, or 3-Bar), it is necessary to know the output voltage from the sensor as a function of pressure. With
the
TECgt
turned on, but the engine NOT running, the MAP sensors will output the voltage for
atmospheric pressure (since manifold pressure is equal to the atmospheric pressure when the engine in not
running). At standard atmospheric conditions (101.3 kPa), the output voltages should be:
1-Bar: approximately 4.80 Volts
2-Bar: approximately 2.30 Volts
3-Bar: approximately 1.55 Volts
Note that the output voltage should be measured between pin “B” (output) and pin “A” (ground). If the
sensor does not output a voltage near the above numbers, the sensor is likely defective. Refer to
Figure
G.1.1
for MAP sensor wiring instructions. Refer to
Figures G.1.2 through 4
for MAP sensor voltage as a
function of manifold pressure for the three MAP sensors.
______________________________________________________________________________________
TECgt Manual Version 2.0
- Page 85 -
©2008 Electromotive, Inc.
