Test Step 5. Disconnect the Sensor in order to Create an Open Circuit

248

TM 9-2320-312-24-2

Troubleshooting Section

Expected Result:

The DC voltage from terminal "A" to terminal "B"

Either a short circuit diagnostic code is active or an

measures 4.5 to 5.5 VDC.

open circuit diagnostic code is active.

Results:

SHORT Circuit A short circuit diagnostic code

OK The sensor supply voltage is correct.

is active at this time. Proceed to Test Step 5.

Remove the Breakout T. Proceed to Test Step 8.

OPEN Circuit An open circuit diagnostic code

Not OK The sensor supply voltage is out of

is active at this time. Proceed to Test Step 6.

range. Continue testing the sensor supply circuit.

Test Step 5. Disconnect the Sensor in

Repair: Proceed to the following repair:

order to Create an Open Circuit.

Troubleshooting, "5 Volt Engine Pressure Sensor

Supply Circuit - Test"

A. Turn the ignition key switch to the OFF position.

STOP.

B. Disconnect the sensor connector of the sensor

Test Step 7. Determine if the Short Circuit

with the short circuit diagnostic code.

is in the Connector or in the Sensor.

C. Turn the ignition key switch to the ON position.

Wait at least 15 seconds for activation of the

A. Thoroughly inspect the connector for moisture.

diagnostic codes.

B. Inspect the seals and reconnect the sensor.

D. Access the "Active Diagnostic Code" screen on

ET. Check for an active open circuit diagnostic

C. If the short circuit diagnostic code reappears,

code.

the sensor or the pigtail harness connector is

the problem.

Expected Result:

a. Temporarily connect a new sensor to the

An open circuit diagnostic code for the

harness, but do not install the new sensor in

disconnected sensor is now active.

the engine.

D. Check for a short circuit diagnostic code while

Results:

the new sensor is connected to the harness.

OK A short circuit diagnostic code was active

before disconnecting the sensor. An open

Expected Result:

circuit diagnostic code became active after

The short circuit diagnostic code is not present

disconnecting the sensor. Proceed to Test Step 7.

when a new sensor is connected.

Not OK There is a short circuit between the

Results:

sensor harness connector and the ECM. Leave

the sensor disconnected. Proceed to Test Step 9.

OK Verify that the repair eliminates the problem.

Test Step 6. Measure the Sensor Supply

Clear the logged diagnostic codes. STOP.

Voltage.

Not OK Repair the engine harness connector.

STOP.

A. Turn the ignition key switch to the OFF position.

Test Step 8. Create a Short Circuit

B. Disconnect the sensor from the engine harness.

Between the Signal and the Common

C. Connect a 3-Terminal breakout T to the engine

harness only. Do Not connect the sensor to the

breakout T.

D. Turn the ignition key switch to the ON position.

E. Set a multimeter to the "VDC" setting. Measure

the voltage from the terminal "A" (pressure

sensor supply) to terminal "B" (sensor common).