Series 60 DDEC V Troubleshooting – Section 49.2 Troubleshooting Flash Code 46, PID 168/FMI 1

Section 49.2
Troubleshooting Flash Code 46, PID 168/FMI 1

The power wiring supplies 12 or 24 volts to the ECM/ECU. The system must be sourced directly from the battery. ‪

Note: Connection to reverse polarity will damage the system if not properly fused.

Flash Code 46 p 168/1 indicates that the main battery supply voltage to the ECM/ECU has dropped below the recommended operating range.‪

The DDEC V system will operate on 12 or 24 volts. ‪

• Normal operating voltage of the DDEC system is 11 to 32 volts DC, measured at the ECM/ECU.
• Operating the ECM/ECU between 6 and 11 volts may result in degraded engine operation. (Transient operation in this range during engine starting is considered normal for 12-volt systems.)
• Operating the ECM/ECU over 32 volts will cause damage.
• Reversing polarity will cause damage to the ECM/ECU if the power harness is not properly fused.

Section 49.2.1
Battery Check

Perform the following steps to check the battery.‪

1. Start and run the engine for one minute.
2. Measure voltage on battery + terminal (red lead) to battery - terminal (black lead). See Figure "Power Wiring" .
   1. If the engine does not start, inspect the battery and charging/starting system, and proceed if okay. Refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .
   2. If the engine does start and the voltage measurement is less than or equal to 10.0 volts, service the discharged battery and charging/starting system.
   3. If the engine does start and the voltage measurement is greater than 10.0 volts, refer to "49.2.2 Voltage Check at ECM/ECU" .
      

      Figure 1. Power Wiring

Section 49.2.2
Voltage Check at ECM/ECU

Perform the following steps to check voltage at the ECM/ECU.‪

1. Keep engine running.
2. Select ECM/ECU INPUT VOLT on the diagnostic tool.
3. Observe ECM/ECU voltage reading on diagnostic tool.
   1. If the voltage measurement is less than or equal to 10.0 volts, refer to "49.2.3 Voltage Check at ECM/ECU Via Volt-Ohm Meter" .
   2. If the voltage measurement is greater than 10.0 volts, refer to "49.2.5 Ground Check at ECM/ECU" .

Section 49.2.3
Voltage Check at ECM/ECU Via Volt-Ohm Meter

Perform the following steps to check voltage at the ECM/ECU.‪

1. Turn the vehicle ignition OFF.
2. Disconnect the Vehicle Interface Harness (VIH) connector at the ECM/ECU.
3. Measure voltage from socket V-61, V-62, V-65, and V-66 (red lead) of the VIH connector and a good battery ground (black lead). Do not use lines (V-63, V-64, or V-68) as a ground reference. See Figure "Vehicle Interface Harness Connector" for the VIH connector. See Figure "Power Wiring" for the power wiring.
   1. If the voltage measurement is less than or equal to 11.5 volts, refer to "49.2.4 Check for Bad Battery + Line" .
   2. If the voltage measurement is greater than 11.5 volts, refer to "49.2.5 Ground Check at ECM/ECU" .
   

   Figure 2. Vehicle Interface Harness Connector

Section 49.2.4
Check for Bad Battery + Line

Perform the following steps to check for a bad battery + line.‪

1. Remove fuse(s) to the ECM/ECU.
2. Measure voltage at socket A of one fuseholder (red lead) to a good ground (black lead). For the VIH connector, see Figure "Vehicle Interface Harness Connector" .
3. Repeat voltage measurement at other fuseholder.
   1. If the voltage measurement is greater than 11.5 volts on both readings, the battery + line between the fuseholder and ECM/ECU has an open, or the ECM/ECU power connector has a corroded connection. Repair the problem. Refer to "49.2.6.1 Verify Repair" .
   2. If the voltage measurement is less than or equal to 11.5 volts on either reading, the battery + line near the battery is open, or a corroded connection exists at battery + terminal. Repair the problem. Refer to "49.2.6.1 Verify Repair" .

Section 49.2.5
Ground Check at ECM/ECU

Perform the following steps to check the ground at the ECM/ECU.‪

1. Disconnect the vehicle harness connectors at the ECM/ECU. See Figure "Vehicle Interface Harness Connector" .
2. Measure voltage on socket V-61 and V-62 to socket V-63 and V-64 and socket V-65 and V-66 connector to socket V-67 and V-68.
   1. If voltage measurement is greater than 11.5 volts on either reading, go to step 3 .
   2. If the voltage measurement is less than or equal to 11.5 volts on either reading, the ground wire is open or has a corroded connection. Repair ground wire, and refer to "49.2.6.1 Verify Repair" .
3. Check terminals at the VIH connector (both ECM/ECU and harness side) for damage; bent, corroded, and unseated pins or sockets.
   1. If terminals and connector are damaged, repair them. Refer to "49.2.6.1 Verify Repair" .
   2. If terminals and connector are not damaged, verify the power and ground are wired directly to the battery. Refer to "49.2.6 Code Check" .

Section 49.2.6
Code Check

Perform the following steps to check for codes.‪

1. Install the Vehicle Interface Module (J-41005–5).
2. Turn ignition ON; plug in the diagnostic tool.
3. Check for codes.
   1. If code reoccurs, install test ECM/ECU, then refer to "49.2.6.1 Verify Repair" .
   2. If code does not reoccur, check power harness wires for breaks, abrasions, etc. Then refer to "49.2.6.1 Verify Repair" .

Section 49.2.6.1
Verify Repair

Perform the following steps to verify repairs.‪

1. Turn vehicle ignition OFF.
2. Reconnect all connectors.
3. Turn ignition ON.
4. Clear codes with diagnostic tool.
5. Start and run the engine for one minute.
6. Stop engine.
7. Check diagnostic tool for codes.
   1. If no codes are displayed, troubleshooting is complete.
   2. If code p 168/1 is not logged, and other codes are logged, refer to "18.3 First Step for Diagnosing a Fault Within the DDEC System" .
   3. If code p 168/1 and other codes are logged, refer to "49.2.1 Battery Check" to troubleshoot the error.