Section 44.2
Troubleshooting Flash Code 41, SID 21/FMI 0
The following procedure will troubleshoot Flash Code 41.
Section 44.2.1
Check for Signal Open
Perform the following steps to check for signal open.
- Turn ignition OFF.
- Disconnect Engine Harness connector at the ECM/ECU. See Figure "Engine Harness Connector" .
- Read resistance between sockets E-17 and E-18 on the Engine Harness connector.
- If the resistance reading is less than or equal to 135 Ω, refer to "44.2.2 Check for Short" .
- If the resistance reading is greater than 136 Ω or open, refer to "44.2.3 Open Crankshaft Position Sensor Line Check" .

Figure 1. Engine Harness Connector
Section 44.2.2
Check for Short
Perform the following steps to check for a short.
- Disconnect the TRS/CKP connector.
- Measure resistance between sockets E-17 and E-18 on the Engine Harness connector. See Figure "Engine Harness Connector to Crankshaft Position Sensor" .
- Measure resistance between socket E-17 and ground, and between socket E-18 and ground.
- If the resistance measurement is greater than 10,000 Ω or open, refer to "44.2.4 Check Crankshaft Position Sensor Resistance and Gap" .
- If the resistance measurement is less than or equal to 10,000 Ω, a short exists between E-17 and E-18 or where less than 10,000 Ω resistance was read. Repair the short. Refer to "44.2.8.1 Verify Repairs" .

Figure 2. Engine Harness Connector to Crankshaft Position Sensor
Section 44.2.3
Open
Crankshaft Position Sensor Line Check
Perform the following steps to check the open TRS/CKP line.
- Disconnect the TRS/CKP connector.
- Install a jumper wire between sockets 1 and 2 of the TRS/CKP harness connector.
- Measure resistance between sockets E-17 and E-18 on the Engine Harness connector.
- If the resistance measurement is less than or equal to 5 Ω, refer to "44.2.4 Check Crankshaft Position Sensor Resistance and Gap" .
- If the resistance measurement is greater than 5 Ω, or open, the signal line E-18 or return line E-17 is open. Repair the open. Refer to "44.2.8.1 Verify Repairs" .
Section 44.2.4
Check Crankshaft Position Sensor Resistance and Gap
Perform the following steps to check TRS/CKP resistance and TRS/CKP/CMP gap:
- Measure resistance of TRS/CKP across sensor connector pins 1 and 2. See Figure
"Engine Harness Connector to Crankshaft Position Sensor"
.
- If the resistance measurement is greater than 136 Ω, go to step 4 .
- If the resistance measurement is between 100 and 135 Ω, go to go to step 2 .

Figure 3. Engine Harness Connector to Crankshaft Position Sensor
- Bar the engine until the TRS/CKP is over a TRS/CKP tooth of the pulse wheel.
- Check the gap between TRS/CKP and the tooth of the pulse wheel (0.020 to 0.040 in.). A depth micrometer can be used.
- If the gap setting is correct, refer to "44.2.5 Camshaft Position Sensor Check" .
- If the gap setting is not correct, adjust the TRS/CKP until the gap setting is correct. If the problem returns, the pulse wheel may be loose or bad or damaged. Refer to "44.2.8.1 Verify Repairs" .
- Check terminals at the TRS/CKP (both the TRS/CKP and harness side) for damaged, bent, corroded, and unseated pins or sockets. See Figure
"Engine Harness Connector to Crankshaft Position Sensor"
- If the terminals and connectors are damaged, repair them. Refer to "44.2.8.1 Verify Repairs" .
- If the terminals and connectors are not damaged, replace the TRS/CKP. Refer to "44.2.8.1 Verify Repairs" .
Section 44.2.5
Camshaft Position Sensor Check
Perform the following steps to check the SRS/CMP:
- Check for SRS/CMP code.
- If code 21/1 is not logged, go to step 3 .
- If code 21/1 is logged, go to step 2 .
- Measure resistance between sockets E-20 and E-19 on the Engine Harness connector. See Figure
"Engine Harness Connector to Camshaft Position Sensor"
.
- If measured resistance is greater than 136 Ω , or open, refer to "44.2.7 Open Camshaft Position Sensor Line Check" .
- If measured resistance is less than 135 Ω , or open, refer to "44.2.6 Check for Short" .

Figure 4. Engine Harness Connector to Camshaft Position Sensor
- Check terminals at the ECM/ECU Engine Harness connectors (both the ECM/ECU and harness side) for damage: bent, corroded, and unseated pins or sockets.
- If terminals and connectors are damaged, repair them. Refer to "44.2.8.1 Verify Repairs" .
- If terminals and connectors are not damaged, install a test ECM/ECU. Refer to "44.2.8.1 Verify Repairs" .
Section 44.2.6
Check for Short
Perform the following steps to check for a short.
- Disconnect the SRS/CMP connector.
- Measure resistance between sockets E-19 and E-20 on the Engine Harness connector.
- If measured resistance is greater than 10,000 Ω, or open, go to step 3 .
- If measured resistance is less than or equal to 10,000 Ω, the signal line E-20 is shorted to the return line E-19. Repair the short. Refer to "44.2.8.1 Verify Repairs" .
- Measure resistance of SRS/CMP across the sensor connector pins 1 and 2.
- If the measured resistance is greater than 136 Ω, go to step 4 .
- If the measured resistance is between 100 and 136 Ω, go to step 5 .
- Check terminals at the SRS/CMP (both the SRS/CMP and harness side) for damage: bent, corroded, and unseated pins or sockets, or bad contacts.
- If terminals and connectors are damaged, repair them. Refer to "44.2.8.1 Verify Repairs" .
- If terminals and connectors are not damaged, replace the SRS/CMP. Refer to "44.2.8.1 Verify Repairs" .
- Check terminals at the ECM/ECU Engine Harness connectors (both the ECM/ECU and harness side) for damage: bent, corroded, and unseated pins or sockets.
- If terminals and connectors are damaged, repair them. Refer to "44.2.8.1 Verify Repairs" .
- If terminals and connectors are not damaged, install a test ECM/ECU. Refer to "44.2.8.1 Verify Repairs" .
Section 44.2.7
Open Camshaft Position Sensor Line Check
Perform the following steps to check for an open SRS/CMP line.
- Disconnect the SRS/CMP connector.
- Install a jumper wire between sockets 1 and 2 of the SRS harness connectors.
- Measure resistance between sockets E-19 and E-20 on the Engine Harness connector.
- If measured resistance is less than or equal to 5 Ω, go to step 4 .
- If measured resistance is greater than 5 Ω, or open, the signal line E-20 or return line E-19 is open. Repair the open and refer to "44.2.8.1 Verify Repairs" .
- Measure resistance of SRS/CMP across the sensor connector pins 1 and 2.
- If the measured resistance is greater than 136 Ω, go to step 5 .
- If the measured resistance is between 100 and 136 Ω, go to step 6 .
- Check terminals at the SRS/CMP (both the SRS/CMP and harness side) for damage: bent, corroded, and unseated pins or sockets, or bad contacts.
- If terminals and connectors are damaged, repair them. Refer to "44.2.8.1 Verify Repairs" .
- If terminals and connectors are not damaged, replace the SRS/CMP. Refer to "44.2.8.1 Verify Repairs" .
- Check terminals at the ECM/ECU Engine Harness connectors (both the ECM/ECU and harness side) for damage: bent, corroded, and unseated pins or sockets.
- If terminals and connectors are damaged, repair them. Check for code 21/0. If there are no codes, refer to "44.2.8.1 Verify Repairs" . If code s 21/0 appears, refer to "44.2.8 Check Injector Drive Harness for Short" and check the injector harness.
- If terminals and connectors are not damaged, install a test ECM/ECU. Check for code s 21/0. If there are no codes, refer to "44.2.8.1 Verify Repairs" . If code s 21/0 appears, refer to "44.2.8 Check Injector Drive Harness for Short" and check the injector harness.
Section 44.2.8
Check Injector Drive Harness for Short
Check the injector drive harness for a short as follows:
- Disconnect the injector harness 10 pin connector and locate the terminals for each injector position. See Figure
"Injector Harness with Jake Brake"
.

Figure 5. Injector Harness with Jake Brake
- Measure resistance between that terminal and the cylinder block.
- If the measured resistance is less than 5Ω, the wire is shorted to the block. Replace the harness between the 10 pin connector and the ECM/ECU. Refer to "44.2.8.1 Verify Repairs" .
- If the measured resistance is greater than 5Ω, call the Detroit Diesel Customer Support Center (313–592–5800).
Section 44.2.8.1
Verify Repairs
Perform the following steps to verify repairs.
- Turn vehicle ignition OFF.
- Reconnect all connectors.
- Turn vehicle ignition ON.
- Start and run the engine for one minute. Stop engine.
- Check diagnostic tool for codes.
- If no codes are logged, troubleshooting is complete.
- If code s 21/0 is logged, check the injector harness for a short to ground (can cause extra pulses). Refer to Chapter "60 Flash Code 61 - Injector Response Long" , section "60.2.3 Check for Short" , “Check for Short.”
- If code s 21/0 and any other codes are logged, and the TRS/CKP or SRS/CMP was not replaced, refer to "44.2.5 Camshaft Position Sensor Check" .
- If code s 21/0 and any other codes are logged and the TRS/CKP or SRS/CMP was replaced, review this section to find the error or contact Detroit Diesel Customer Support Center (313–592–5800).
- If any codes except code s 21/0 are logged, refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .
| Series 60 DDEC V Troubleshooting Guide - 6SE570 |
| Generated on 10-13-2008 |