Component Test

IMPORTANT: You must perform the Circuit/System Testing to verify the integrity of the sensor circuits before proceeding with the Component Testing.

Skew Sensor Test

Ignition OFF, remove the vacuum source from the sensor.
Ignition ON, observe and record the scan tool sensor pressure parameter. This is the first sensor reading.
With the J 23738-A or the J 35555 , apply 5 in Hg (17 kPa) of vacuum to the sensor. See Special Tools . Observe and record the scan tool sensor pressure parameter. This is the second sensor reading.
Subtract the second sensor reading from the first sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.
- If the vacuum decrease is not within the specified range, replace the sensor
With the J 23738-A or the J 35555 , apply 10 in Hg (34 kPa) of vacuum to the sensor. See Special Tools . Observe and record the scan tool sensor pressure parameter. This is the third sensor reading.
Subtract the third sensor reading from the first sensor reading. Verify that the vacuum decrease is within 1 in Hg (4 kPa) of the applied vacuum.
- If the vacuum decrease is not within the specified range, replace the sensor.

Erratic Signal Test

Ignition OFF, remove the sensor.
Install a 3A fused jumper wire between the 5-volt reference circuit terminal C and the corresponding terminal of the sensor.
Install a jumper wire between the low reference circuit terminal A of the sensor and ground.
Install a jumper wire at the terminal B of the sensor.
Connect a DMM between the jumper wire from terminal B of the sensor and ground.
Ignition ON, with the J 23738-A or the J 35555 slowly apply vacuum to the sensor while monitoring the voltage on the DMM. See Special Tools . The voltage should vary between 0-5.2 volts, without any spikes or dropouts.
- If the voltage is not within the specified range or is erratic, replace the affected sensor.