Perform an accuracy test of the J 44175 Fuel Composition Tester.

1. Fill the tester with acetone.
2. Connect a DMM to the tester terminals
3. Set the DMM to AC hertz scale and take a reading.

Is the reading within 6 Hz of the specification?

136 Hz

Go to Step 2

Go to Step 7

Important: Drain the acetone completely from the tester. Clean the beaker with a clean dry paper towel before taking a fuel sample. Be careful not to allow fingerprints, sweat, water or any other outside debris contaminate the fuel sample, beaker, tester or fuel gauge as this will cause an error in the test result, leading to a misdiagnosis.

1. Perform a fuel test using the fuel composition tester.
2. Install a fuel pressure gauge into the service port located on the rear of the injector rail.
3. Start the engine and open the valve on the fuel pressure gauge. Allow enough fuel to pass through the gauge to flush any previous fuel from inside the hose.
4. Draw fuel from the fuel pressure gauge into the beaker supplied with the test kit.
5. Transfer the fuel from the beaker into the fuel tester.
6. Turn ON the fuel tester and note the red and green LED.

Is the green LED ON?

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Go to Step 4

Go to Step 3

Is the red LED ON?

--

Go to Step 5

Go to Step 7

1. Connect a DVM to the fuel tester terminals.
2. Set the DVM to the AC Hz scale and take a reading of the fuel sample.
3. Start the engine and monitor the fuel composition frequency on the scan tool.

Is the reading from the scan tool and the DVM within the specified amount?

12 Hz

System OK

Go to Step 6

1. The fuel is contaminated.
2. Follow the Fuel Tank Draining Procedure and drain the fuel from the tank. Refer to Fuel Tank Draining .
3. Replace the fuel.

Is the action complete?

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System OK

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Replace the fuel composition sensor. Refer to Fuel Composition Sensor Replacement .

Is the action complete?

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System OK

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Replace the 9-volt battery and retest. If the result is the same, the tester will need to be sent out for repair.

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