DDEC III/IV Single ECM Troubleshooting – Section 16.4 Maintenance Alert System

Section 16.4
Maintenance Alert System

Listed in Table "Troubleshooting Add Coolant Level Sensor" , are the flash codes for ACLS problems.‪

Flash‪ Code‪	PID‪ FMI‪	Description‪	Typical Cause‪
13‪	111/6‪	ACLS failed low‪	Signal wire (#906) shorted low (ground)‪
16‪	111/5‪	ACLS failed high‪	Open or poor ground. Open signal wire‪
43‪	111/1‪	Coolant level low (ACLS)‪	Coolant level below probe‪
89‪	111/12‪	ACLS Fault‪	Coolant reported low on main CLS, with ACLS okay‪

Troubleshooting 111/6, Flash Code 13 follows: ‪

Section 16.4.1
Check Sensor

Follow these steps to check the sensor:‪

1. Unplug the ACLS.
2. Insert a jumper between cavities A and B of the sensor connector.
3. Start the engine.
4. Plug in the DT. Read the codes displayed.
   1. If code 13, (111/5) displays, replace the ACLS. Go to test. Refer to "16.4.5 Test Repair" . See Figure "Maintenance Alert System " .
      

      Figure 1. Maintenance Alert System

   2. If code 16 (111/6) displays, go to the next procedure. Refer to "16.4.2 Check for Open" .

Section 16.4.2
Check for Open

Perform the following steps to check for open:‪

1. Insert a jumper wire between cavities A and B of the ACLS module connector. See Figure "Maintenance Alert System " .
2. Measure resistance between cavities A and B of the sensor connector.
   1. If measured resistance is greater than 10 Ω, the ground wire of the #116 wire is open. Repair the open and go to test. Refer to "16.4.5 Test Repair" .
   2. If measured resistance is less than 10 Ω, refer to "16.4.3 Check for Voltage" .

Section 16.4.3
Check for Voltage

Perform the following steps to check for voltage:‪

1. Turn the ignition ON.
2. Measure the voltage between cavities E and C of the ACLS module connector. See Figure "Maintenance Alert System " .
   1. If measured voltage is 11.0 volts or greater, refer to "16.4.5 Test Repair" .
   2. If measured voltage is less than 11.0 volts, determine the reason for loss of ignition voltage.

Section 16.4.4
Check for Open Signal

Perform the following steps to check for open signal: ‪

1. Turn the ignition OFF.
2. Unplug the engine harness 30–pin connector.
3. Insert a jumper wire between cavity N1 (#906) and battery ground.
4. Measure resistance between cavities D and C of the ACLS module connector.
   1. If the measured resistance is greater than 10 Ω, the #906 wire or the battery ground wire is open between the ACLS module connector and the engine harness 30–pin connector. Repair the open; replace the wire and go to test. Refer to "16.4.5 Test Repair" .
   2. If the measured resistance is less than 10 Ω, replace the ACLS module; go to test. Refer to "16.4.5 Test Repair" .

Section 16.4.5
Test Repair

Perform the following steps to test the repair: ‪

1. Connect all removed connectors.
2. Start and run engine for five minutes.
3. Plug in DDR.
4. Read active codes.
   1. If no codes display, repairs are complete. Return the unit to service.
   2. If code 16 displays, troubleshooting is complete. Review the above steps to find the error.
   3. If any other codes are logged, refer to "9.1 First Step for Diagnosing a Fault Within the DDEC System" .