Detroit Diesel Troubleshooting Diagrams

To determine if a defective turbocharger is causing excessive exhaust smoke, perform the following: ‪

1. Remove the turbocharger outlet line connected to the crankcase and place the drain line into a suitable container;
2. Perform a crankcase pressure test.
   1. If the engine crankcase pressure is greater than 3 in. H ₂ O (0.75 kPa), replace the turbocharger;
   2. If the engine crankcase pressure is 3 in. H ₂ O (0.75 kPa), call the Detroit Diesel Technical Service Group.

Turbocharger Replacement

Perform the following steps to replace a defective turbocharger: ‪

1. Remove defective turbocharger from the engine;
2. Tag removed turbocharger for remanufacture.
3. Install a new turbocharger to the engine;
4. Verify replacement of new turbocharger;

Test Engine with Replaced Turbocharger

Perform the following steps to determine if a replaced turbocharger resolved the excessive exhaust smoke condition: ‪

1. Start the engine.
2. Run the engine speed to full load.
3. Visually inspect the exhaust for excessive smoke.
   1. If the engine exhaust emission appears normal, no further troubleshooting is required. Shut down the engine.
   2. If the engine exhaust emission is excessive, shut down the engine. Call Detroit Diesel Technical Service Group.

To determine if a faulty fuel injector is causing the cylinder to misfire, perform the following steps: ‪

1. Install DDL adaptor to the data cable and plug the adaptor into the DDL connector in the vehicle; refer to OEM guidelines.
2. Start and run the engine at no-load.
3. From the DDEC III/IV Select Menu, scroll to select ENGINE and press the ENTER key.
4. Scroll to FUEL INJECTOR INFO (CUTOUT) and press the ENTER key.
5. Scroll to select NEW TEST and press the ENTER key.
6. Scroll to select RPM SETTING FOR CCO TEST NORMAL and scroll to select 1000 and press the ENTER key.
7. Scroll to select AUTO and press the ENTER key. Wait for END OF TEST.

Note: If an injector cannot be cutout, an ERROR message will appear. Press FUNC to exit the cylinder cutout function, press the FUNC key.

8. Scroll the list to review the results of the cylinder cutout test. To find suspect injectors, look for a cylinder with a value that is within 0.2 ° of the NO CUTOUT PULSE WIDTH, by comparing the CUTOUT PULSE WIDTH values to the NO CUTOUT PULSE WIDTH values.

If any CUTOUT PULSE WIDTH values are within 0.2 ° of the NO CUTOUT PULSE WIDTH, shut down the engine;
If any CUTOUT PULSE WIDTH values are not within 0.2 ° of the NO CUTOUT PULSE WIDTH, shut down the engine

To determine if a faulty exhaust system is causing excessive exhaust smoke, perform the following:

1. Drill an 11/32 in. hole in the exhaust pipe, 5 to 12 in. (127 – 305 mm) from the turbocharger exhaust outlet.

Note: The tapped hole must be in a comparatively straight area of the turbocharger exhaust outlet.

2. Tap the hole to accommodate an 1/8 in. pipe plug.
3. Connect a manometer to the tapped hole.
4. Start and run the engine.
5. Run the engine at idle with a no-load for approximately 5 minutes, allowing the engine coolant to reach normal operating range.
6. Run the engine speed to full load.

If the exhaust back pressure at full load is less than 3.0 in. Hg (10.1 kPa), check the fuel injectors.
If the exhaust back pressure at full load is 3.0 in. Hg (10.1 kPa) or greater

To determine if a charge air cooler is causing excessive exhaust smoke, perform the following: ‪

1. Attach a WK93 air-to-air charge air cooler test kit; refer to OEM guidelines.
2. Disconnect the air inlet hose from the outlet side of the turbocharger compressor housing;
3. Attach the air-to-air cooler test kit adaptor plug to fit into the hose at the compressor connector; refer to OEM guidelines.
4. Attach an air pressure hose to the air chuck at the regulator and gradually pressurize the air inlet system to a pressure of 25 · lb · in. 2 (177 kPa).
5. Apply a water and soap solution to each hose connection, across the face of the charge air cooler.
6. Apply a water and soap solution to the air intake manifold and cylinder head mating surface area.
7. Visually inspect all joints for air leaks and all charge air cooler welded surfaces for stress cracks

If air leaks are present around the joints, replace the charge air cooler;
If any leaks are present around the air intake manifold, repair the air intake manifold;
If no leaks are present, check for faulty exhaust system;