Service manual

90-898303

4-27

5. The voltmeter should read +5 volts, if not, connect the voltmeter across the

PPL/YEL wire and the engine ground. If the voltmeter indicates +5 volts, there

is an open in the ground circuit (BLK/ORN).

NOTE: All the ground wires for the sensors are spliced together and connect

to the PCM at (Pin 22 of A connector). Unless there are multiple sensor

failures, the most likely failure would be at the splice point, the connector or in

between the connector and the splice point.

6. If the the voltmeter does not indicate +5 volts, there is an open circuit

between the PCM and the connector (PPL/YEL).

NOTE: All the +5 volts power wires for the sensors are spliced together and

connect to the PCM (pin 22 of A connector). Unless there are multiple sensor

failures, the most likely failure would be at the splice point, the connector or in

between the connector and the splice point.

7. Test the sensor.

a. Remove the sensor from the engine and attach the connector to the

sensor.

b. Insert the positive probe of a voltmeter to the input lead of the

connector going to the PCM.

c. Insert the negative probe of the voltmeter at the ground (BLK/ORN)

lead of the connector.

d. Attach a vacuum gauge to the sensor and refer to the table to

determine the voltage reading at the applied pressure. If there is no

input voltage or if the input voltage is incorrect, replace the sensor and

retest.

Volts

0.0 0.3 0.6 0.9 1.3 1.5 1.9 2.1 2.5 2.8 3.1 3.4 3.8 4.0 4.4 4.7 4.9

kPa 10 16 22 28 34 40 46 52 58 63 69 75 81 87 93 99 105

InHg 27 25 23 21 20 18 16 14 13 11 9.1 7.3 5.6 3.8 2.1 0.3 -1

8. If the voltage was present at the sensor insert a probe at the yellow input

wire to the PCM (pin 3, connector A). If no input voltage is present, repair the

wire from the sensor to the PCM and retest.

9. If voltage is present at the PCM, replace the PCM and retest.

Notes

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