DTC P1628:00

DC-DC converter system: power supply voltage low input

DETECTION CONDITION

• An ignition off determination continues while the DC-DC converter receives signals during a 5 s period from the PCM at intervals of less than 0.1 s.

FAIL-SAFE FUNCTION

• Not applicable

POSSIBLE CAUSE

• DC-DC converter connector or terminals malfunction

• Short to ground or open circuit in DC-DC converter power supply circuit

• Short to ground in wiring harness between IG1 relay terminal C and DC-DC converter terminal 1H

• C/U IG1 15 A fuse malfunction

• Open circuit in wiring harness between IG1 relay terminal C and DC-DC converter terminal 1H

• Short to ground in wiring harness between electric load (such as start stop unit or non-genuine part) connected to C/U IG1 15 A fuse and C/U IG1 15 A fuse, or short to ground in electric load part

• DC-DC converter malfunction

STEP

INSPECTION

ACTION

1

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

2

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Disconnect the service plug.

  (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].)

• Disconnect the DC-DC converter connector.Disconnect the DC-DC converter connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 5.

No

Go to the next step.

3

• Verify that the DC-DC converter connector is disconnected.

• Reconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Switch the ignition ON (engine off).

• Measure the voltage at the DC-DC converter terminal 1H (wiring harness-side).

• Is the voltage B+?

Yes

Go to the next step.

No

Inspect the C/U IG1 15 A fuse.

• If the fuse is blown out:

• Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay terminal C and DC-DC converter terminal 1H.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

• Replace the fuse.

• If the fuse is damaged:

• Replace the fuse.

• If the fuse is normal:

• Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay terminal C and DC-DC converter terminal 1H.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 5.

4

• Switch the ignition off.

• Disconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Verify the wiring harness condition related to the electric load part connected to the C/U IG1 15 A fuse.

• Is there any malfunction?

Yes

Repair or replace the malfunction part, then go to the next step.

No

Go to the next step.

5

• Always reconnect all disconnected connectors.

• Reconnect the negative battery cable.

  (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.5].)

• Reconnect the service plug.

  (See SERVICE PLUG DISCONNECTION/CONNECTION [i-ELOOP].)

• Clear the DTC for the DC-DC converter using the M-MDS.

  (See CLEARING DTC [i-ELOOP].)

• Switch the ignition off.

• Switch the ignition ON (engine off) and wait for 5 s or more.

• Retrieve the DC-DC converter DTCs using the M-MDS.

  (See DTC INSPECTION [i-ELOOP].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the DC-DC converter.

  (See DC-DC CONVERTER REMOVAL/INSTALLATION [i-ELOOP].)

Go to the next step.

No

Go to the next step.

6

• Are any other DTCs displayed?

Yes

Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.

(See DTC TABLE [i-ELOOP].)

No

DTC troubleshooting completed.