ISSPRO EV² Series - Manual (Page 2)

For the 400 psi sensor (Trans Pressure and Drive Oil Pressure gauges) –
PSI 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400
Voltage 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5
If the voltage is more than 0.4 volts from the values listed above, the sensor is probably faulty and
should be replaced.
Rail Pressure Gauges:
5. If the gauge performs the homing functions of step #1 but the pointer moves to the straight down (6:00)
position, the sensor reading is out of range. Perform the following checks in order, with the orange
connector plugged in and ignition turned on:
a. Check that the connection between the factory harness and the gauge harness is correct. Be sure
that the truck harness connector is oriented so that its latch engages the angled block on the Rail
Pressure harness connector, not the non-angled block on the other side of the connector.
b. Check the voltage between the actual wires (rather than the terminals) by probing the ends of the
wires, between pin #5 and pin #6. It should be between 0.5 and 4.5 volts. If it is outside this
range, the sensor or wiring is damaged.
c. Checking at the terminals of the orange connector, check the voltage between pin #5 and pin #6.
It should be between 0.5 and 4.5 volts. If it is outside this range but within the range when
checking at the wires, check that the wires are sufficiently seated into the orange connector to
make electrical contact.
Pyrometers:
6. If the gauge performs the homing functions of step #1 but the pointer moves to the straight down (6:00)
position, the sensor reading is out of range. Perform the following checks in order, with the orange
connector disconnected from the gauge:
a. Using a digital multimeter set on millivolts, measure the voltage between pins 4 & 5 (red and
yellow wires), checking at the terminals of the orange connector.
b. Check the voltage between the actual wires (rather than the terminals) by probing the ends of the
wires, between the red and yellow wires. Your value should be within 0.02 millivolts of the value
measured at the terminals in step a. If there is a difference, check the connection between the
wires and the connector terminals.
c. The values measured above, on a cold engine, with the vehicle interior approximately the same as
the exhaust system, should be approximately 0 millivolts. With the engine idling (exhaust gas
temperature approximately 300°F) and the vehicle interior at approximately 70°F, you should
measure approximately 5.28 millivolts. If there are any problems with these measurements check
the wiring to the thermocouple.
Temperature Gauges:
7. If the gauge performs the homing functions of step #1 but the pointer moves to the straight down (6:00)
position, the sensor reading is out of range. Perform the following checks in order, with the orange
connector disconnected from the gauge:
d. Using a digital multimeter set on resistance (ohms), measure the resistance between pins 4 & 5
(green and white wires), checking at the terminals of the orange connector. The resistance value
should follow the chart below. If more than 150 ohms off these values, unplug the wiring at the
sensor and re-check at the terminals of the sensor. If the value is still more than 150 ohms off, the
sensor is defective and should be replaced.
Temp °F 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Res
(Ohms) 22.5K 17.3K 13.4K 10.4K 8.17K 6.45K 5.13K 4.10K 3.30K 2.68K 2.19K 1.80K 1.49K 1.24K