DDEC III/IV Single ECM Troubleshooting – Section 43.3 Troubleshooting Flash Code 43

Section 43.3
Troubleshooting Flash Code 43

The following procedure will troubleshoot Flash Code 43.‪

Section 43.3.1
Coolant Level Low

Perform the following steps to diagnose the coolant level low.‪

1. Turn ignition ON; plug in Diagnostic Data Reader (DDR).
2. Read active codes.
   1. If code p 111/1 is logged, there is an indication of a low coolant level condition. Add coolant to ensure coolant level probe is immersed in coolant.
   2. If code p 111/1 remains active, refer to "43.3.2 Test Relative Humidity/Turbo Compressor Inlet Temperature Sensor Circuit" .
   3. If code p 111/1 is no longer active, troubleshooting is done. Return engine to service.

Section 43.3.2
Test Relative Humidity/Turbo Compressor Inlet Temperature Sensor Circuit

After ensuring the coolant level is correct, troubleshoot Flash Code 43 as follows: ‪

Note: On DDEC IV S60 EGR engines, an open wire for the Relative Humidity/Turbo Compressor Inlet (TCI) Temperature Sensor circuit can sometimes generate Flash Code 43.

1. Unplug TCI Temperature Sensor connector.
2. Unplug the 10-pin connector on the engine sensor harness next to the ECM.
3. Install a jumper wire between cavities 1 and 2 of the TCI Temperature Sensor connector.
4. Measure resistance between cavities 3 and 4 of the 10-pin connector.
   1. If greater than 5 Ω, wire 452 is open. Repair open wire 452 and verify repairs. Refer to "43.3.5 Verify Repairs" .
   2. If less than 5 Ω, refer to "43.3.3 Replace Coolant Level Sensor / Add Coolant Level Sensor" .

Section 43.3.3
Replace Coolant Level Sensor / Add Coolant Level Sensor

Using the DDEC sensor tester (J-37164-B) may be of assistance. ‪

Note: When replacing the CLS/ACLS, it could be an OEM-supplied part.

1. Turn ignition OFF; replace CLS/ACLS.
2. Turn ignition ON.
3. Read active codes.
   1. If no codes are logged, troubleshooting is complete.
   2. If codes are logged, refer to "43.3.4 Clean and Check Alternator Grounds" .

Section 43.3.4
Clean and Check Alternator Grounds

Perform the following steps to check the alternator ground.‪

1. If the grounds are clean and good, troubleshooting is complete.
2. If the grounds are damaged, repair the ground circuit and verify repairs. Refer to "43.3.5 Verify Repairs" .

Section 43.3.5
Verify Repairs

Perform the following steps to verify repairs‪

1. Turn ignition OFF.
2. Reconnect all connectors.
3. Turn ignition ON.
4. Clear DDR codes.
5. Start and run the engine for one minute.
6. Stop engine.
7. Check DDR for codes.
   1. If no codes are logged, troubleshooting is complete.
   2. If code p 111/1, and any other codes are logged, refer to "43.3.1 Coolant Level Low" , and repeat the procedure, or contact Detroit Diesel Technical Service.
   3. If any code other than p 111/1 is logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .