MBE 900 4000 Troubleshooting – Section 19.2 Troubleshooting SID 21

Section 19.2
Troubleshooting SID 21

Perform the following steps to troubleshoot SID 21.‪

Section 19.2.1
021 01 – Crankshaft Position Sensor Signal Voltage Too Low

Troubleshoot a CKP sensor signal voltage too low fault as follows:‪

1. If fault occurs only when cranking the engine (and engine will not start), check that the CKP and Camshaft Position (CMP) sensors are correctly wired to the PLD-MR. See Figure "Crankshaft Position Sensor and Camshaft Position Sensor Wiring" .
   

   Figure 1. Crankshaft Position Sensor and Camshaft Position Sensor Wiring

   1. If wires are not correctly wired, repair or replace wires as required. Erase fault code memory.
   2. If wires are correctly wired, go to step 2 .
2. If fault occurs at other times then when cranking the engine (and engine will not start), check the CKP sensor position.
   1. If fault is not active after checking CKP sensor position, repair the CKP sensor clamping sleeve. Erase fault code memory.
   2. If fault is still active after checking the CKP sensor position, go to step 3 .
3. Check the flywheel sensor position through the inspection window of the timing case using turning tool.
   1. If sensors are out of position, repair or replace, as required. Erase fault code memory.
   2. If sensors are not out of position, go to step 4 .
4. Check crankshaft axial play.
   1. If axial play is not within specifications, repair or replace crankshaft thrust bearings, as required. Erase fault code memory.
   2. If axial play is within specifications, contact Detroit Diesel Technical Service.

Section 19.2.2
021 03 – Crankshaft Position Sensor Open Circuit

Troubleshoot a CKP sensor open circuit fault as follows:‪

1. Bridge pins 2 and 19 on the 55-pin connector. See Figure "Crankshaft Position Sensor and Camshaft Position Sensor Wiring" . Pin locations are listed in Table "Selected Harness Pin Locations" .
   1. If new fault 021 04 is active, replace CKP sensor and clamping sleeve. Erase fault code memory.
   2. If new fault 021 04 is not active, go to step 2 .
2. Check and clean contacts.
   1. If fault 021 03 is still active, contact Detroit Diesel Technical Service for authorization to replace the PLD-MR. Set parameters on the new PLD-MR.
   2. If fault 021 03 is not active, erase fault code memory.

Section 19.2.3
021 04 – Crankshaft Position Sensor Short to Ground

Troubleshoot a CKP sensor short to ground fault as follows:‪

1. Unplug the 55-pin connector from the PLD-MR.
   1. If new fault code 021 03 is active, replace the CKP sensor and clamping sleeve. Erase fault code memory.
   2. If new fault code 021 03 is not active, go to step 2 .
2. Check and clean contacts.
   1. If fault 021 04 is active, contact Detroit Diesel Technical Service for authorization to replace the PLD-MR. Set parameters on the new PLD-MR.
   2. If fault 021 04 is not active, check the contact, clean contacts (if necessary), and erase fault code memory.

Section 19.2.4
021 07 – No Match of Camshaft and Crankshaft Signals

Troubleshoot a no match of camshaft and crankshaft signals fault as follows:‪

1. Perform a polarity test on the engine speed sensor.
   1. If fault 021 07 is not active after performing test, erase fault code memory.
   2. If fault 021 07 is active after performing test, go to step 2 .
2. Reseat the CKP and CMP sensors and check for crossed wires on the 55-pin connector. See Figure "Crankshaft Position Sensor and Camshaft Position Sensor Wiring" .
   1. If wires are crossed, repair or replace wires. Erase fault code memory.
   2. If wires are not crossed, contact Detroit Diesel Technical Service.

Section 19.2.5
021 08 – Sensor Time Out

Troubleshoot a sensor time out fault, as follows:‪

1. If fault 021 03 is active in addition to fault 021 08 with engine running, refer to "19.2.2 021 03 – Crankshaft Position Sensor Open Circuit" .
2. If fault 021 04 is active in addition to fault 021 08 with engine running, refer to "19.2.3 021 04 – Crankshaft Position Sensor Short to Ground" .
3. Check the sensor position.
   1. If fault 021 08 is not active after checking position, replace CKP sensor clamping sleeve. Erase fault code memory.
   2. If fault 021 08 is active after checking position, go to step 4 .
4. Perform a polarity test on the CKP sensor.
   1. If test confirms polarity is reversed (fault 021 14 is present), check for crossed wires on the 55-pin connector and repair or replace wires. See Figure "Crankshaft Position Sensor and Camshaft Position Sensor Wiring" . Erase fault code memory.
   2. If sensor polarity is not reversed, go to step 5 .
5. Replace the engine speed sensor.
   1. If fault 021 08 is not active, erase fault code memory.
   2. If fault 021 08 is still active, go to step 6 .
6. Check the flywheel sensor position in the timing case through the inspection window using turning tool.
   1. If sensors are out of position, repair or replace the spring bushing, as required. Erase fault code memory. See Figure "Crankshaft Position Sensor Location" .
      

      1. Crankshaft Position Sensor Bracket‪	4. Crankshaft Position Sensor‪
      2. Shear Bolt‪	5. Reference Hole on the Flywheel Edge‪
      3. Spring Bushing‪	‪

      Figure 2. Crankshaft Position Sensor Location

   2. If sensors are not out of position, go to step 7 .
7. Check crankshaft axial play.
   1. If axial play is not within specifications, repair or replace crankshaft thrust bearings, as required. Erase fault code memory.
   2. If axial play is within specifications, contact Detroit Diesel Technical Service.

Section 19.2.6
021 14– Pins Swapped

Troubleshoot a pins swapped fault as follows:‪

1. Perform a polarity test on the engine speed sensor.
   1. If polarity is not reversed, erase fault code memory.
   2. If polarity is reversed (fault 021 14 is present), go to step 2 .
2. Reseat the CKP and CMP sensors and check for crossed wires. See Figure "Crankshaft Position Sensor and Camshaft Position Sensor Wiring" .
   1. If crossed wires are found, repair or replace wires. Erase fault code memory.
   2. If crossed wires are not found, contact Detroit Diesel Technical Service.