DTC 41

System Schematic:

To test the Injectors, located between the fuel rail and the head, proceed as follows.



OSCILLOSCOPE TEST

Oscilloscope Pattern:

1. Run the engine until it reaches operating temperature. Maintain idle speed for testing.
2. connect the scope pick-up probe to the test points shown in the system schematic. Compare the scope pattern to the image shown. If scope pattern is not as depicted in image, continue with the rest of the test procedures before replacing the assembly.




FUNCTIONAL TEST

Operational Test:

Using a stethoscope, check the operational sound (tick) made by the injectors (one at a time) during idle or cranking. Check that the sound is produced at shorter intervals as the engine speed increases.

CAUTION: Other injectors may produce sound as they operate even if the injector being tested does not operate. Ensure that the sound from an adjacent injector is not being transmitted along the delivery pipe to an inoperative injector.

Resistor Test:

RESISTANCE MEASUREMENT BETWEEN TERMINALS:
1. Disconnect the connector for the injector.
2. Measure the resistance between the terminals.

Standard Value...13-16 ohm (20°C/68°F)

HARNESS TEST

1. Disconnect the injector connector and turn on the ignition.
2. Using a voltmeter, measure the power supply voltage between each injector harness connector terminal 1 and ground.

Voltage: System Voltage.

3. Turn off the ignition and disconnect the ECU connector. Using an Ohmmeter, check for continuity (short) to ground, between the ECU harness connector terminals 51, 52, 53, 54, 55 and 56 and the injector connectors harness terminal 2.

Continuity: Should Not Exist.

4. Using an Ohmmeter, check for continuity between the ECU harness connector terminals 51, 52, 53, 54, 55 and 56 and the injector connectors harness terminal 2.

Continuity: Should Exist.




If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, clear the trouble codes and road test the vehicle to confirm that the repair has corrected the problem and the code doesn't return.

If the same trouble code reoccurs, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.