DTC P1794:16 [GATEWAY UNIT (GWU) (TYPE-B)]

id0902zc790900

Outline

System malfunction location

Gateway unit (GWU) low power supply voltage input

Detection condition

•  The gateway unit (GWU) power supply circuit voltage is lower than the standard.

Fail-safe

Not applicable

Possible cause

•  DTCs are stored in the PCM.

•  Battery malfunction

•  Malfunction in generator

•  Gateway unit (GWU) connector or terminal malfunction

•  Short to ground or open circuit in gate way unit (GWU) power supply circuit

•  Gateway unit (GWU) malfunction

System malfunction location	Gateway unit (GWU) low power supply voltage input
Detection condition	• The gateway unit (GWU) power supply circuit voltage is lower than the standard.
Fail-safe	Not applicable
Possible cause	• DTCs are stored in the PCM. • Battery malfunction • Malfunction in generator • Gateway unit (GWU) connector or terminal malfunction • Short to ground or open circuit in gate way unit (GWU) power supply circuit • Gateway unit (GWU) malfunction

Diagnostic Procedure

Step

Inspection

Results

Action

1

INSPECT PCM FOR MALFUNCTION

•  Perform the DTC inspection for the PCM.
(See DTC INSPECTION.)

•  Is a DTC displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

(See DTC TABLE [PCM (SKYACTIV-D 2.2)].)

(See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)

(See DTC TABLE [PCM (WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].)

(See DTC TABLE [PCM (WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].)

No

Go to the next step.

2

INSPECT BATTERY FOR MALFUNCTION

•  Inspect the applicable part.
(See BATTERY INSPECTION.)

•  Is the part normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

(See BATTERY RECHARGING.)

(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)

(See BATTERY REMOVAL/INSTALLATION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See BATTERY REMOVAL/INSTALLATION [WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

3

INSPECT GENERATOR FOR MALFUNCTION

•  Inspect the applicable part.
(See GENERATOR INSPECTION [SKYACTIV-D 2.2].)

(See GENERATOR INSPECTION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See GENERATOR INSPECTION [WITHOUT i-ELOOP (WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].)

(See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

(See GENERATOR INSPECTION [WITH i-ELOOP (SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION))].)

•  Is the part normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

(See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)

(See GENERATOR REMOVAL/INSTALLATION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See BATTERY REMOVAL/INSTALLATION [WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].)

(See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)

(See GENERATOR REMOVAL/INSTALLATION [WITH i-ELOOP (SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION))].)

4

INSPECT GATEWAY UNIT (GWU) CONNECTOR FOR MALFUNCTION

•  Inspect the applicable connector and terminal.
(See CONNECTOR INSPECTION.)

•  Are the connector and terminal normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

5

INSPECT GATE WAY UNIT (GWU) POWER SUPPLYCIRCUIT FOR SHORT TO GROUND AND OPENCIRCUIT

•  Inspect the applicable circuit for a short to ground and open circuit.
(See CIRCUIT INSPECTION.)

•  Is the circuit normal?

Yes

Go to the next step.

No

Repair or replace the malfunctioning location and perform the repair completion verification.

Repair completion verification 1

VERIFY THAT VEHICLE IS REPAIRED

•  Install/connect the part removed/disconnected during the troubleshooting procedure.

•  Clear the DTC recorded in the memory.
(See CLEARING DTC.)

•  Perform the DTC inspection for the gateway unit (GWU).
(See DTC INSPECTION.)

•  Is the same Pending DTC present?

Yes

Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [TYPE-B (L.H.D.)].)

(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [TYPE-B (R.H.D.)].)

If the CAN communication is normal, perform the diagnosis from Step 1.

•  If the malfunction recurs, replace the gateway unit (GWU), then go to the next step.
(See GATEWAY UNIT (GWU) REMOVAL/INSTALLATION [TYPE-B].)

No

Go to the next step.

Repair completion verification 2

VERIFY IF OTHER DTC IS DISPLAYED

•  Perform the DTC inspection.
(See DTC INSPECTION.)

•  Are any other DTCs displayed?

Yes

Repair the malfunctioning location according to the applicable DTC troubleshooting.

No

DTC troubleshooting completed.

Step	Inspection	Results	Action
1	INSPECT PCM FOR MALFUNCTION • Perform the DTC inspection for the PCM. (See DTC INSPECTION.) • Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-D 2.2)].) (See DTC TABLE [PCM (SKYACTIV-G 2.5T)].) (See DTC TABLE [PCM (WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].) (See DTC TABLE [PCM (WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].)
1		No	Go to the next step.
2	INSPECT BATTERY FOR MALFUNCTION • Inspect the applicable part. (See BATTERY INSPECTION.) • Is the part normal?	Yes	Go to the next step.
2		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See BATTERY RECHARGING.) (See BATTERY REMOVAL/INSTALLATION [SKYACTIV-D 2.2].) (See BATTERY REMOVAL/INSTALLATION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See BATTERY REMOVAL/INSTALLATION [WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See BATTERY REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
3	INSPECT GENERATOR FOR MALFUNCTION • Inspect the applicable part. (See GENERATOR INSPECTION [SKYACTIV-D 2.2].) (See GENERATOR INSPECTION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See GENERATOR INSPECTION [WITHOUT i-ELOOP (WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5))].) (See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].) (See GENERATOR INSPECTION [WITH i-ELOOP (SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION))].) • Is the part normal?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning location and perform the repair completion verification. (See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-D 2.2].) (See GENERATOR REMOVAL/INSTALLATION [WITHOUT CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See BATTERY REMOVAL/INSTALLATION [WITH CYLINDER DEACTIVATION (SKYACTIV-G 2.0, SKYACTIV-G 2.5)].) (See GENERATOR REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].) (See GENERATOR REMOVAL/INSTALLATION [WITH i-ELOOP (SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION))].)
4	INSPECT GATEWAY UNIT (GWU) CONNECTOR FOR MALFUNCTION • Inspect the applicable connector and terminal. (See CONNECTOR INSPECTION.) • Are the connector and terminal normal?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT GATE WAY UNIT (GWU) POWER SUPPLYCIRCUIT FOR SHORT TO GROUND AND OPENCIRCUIT • Inspect the applicable circuit for a short to ground and open circuit. (See CIRCUIT INSPECTION.) • Is the circuit normal?	Yes	Go to the next step.
5		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification 1	VERIFY THAT VEHICLE IS REPAIRED • Install/connect the part removed/disconnected during the troubleshooting procedure. • Clear the DTC recorded in the memory. (See CLEARING DTC.) • Perform the DTC inspection for the gateway unit (GWU). (See DTC INSPECTION.) • Is the same Pending DTC present?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [TYPE-B (L.H.D.)].) (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [TYPE-B (R.H.D.)].) If the CAN communication is normal, perform the diagnosis from Step 1. • If the malfunction recurs, replace the gateway unit (GWU), then go to the next step. (See GATEWAY UNIT (GWU) REMOVAL/INSTALLATION [TYPE-B].)
Repair completion verification 1		No	Go to the next step.
Repair completion verification 2	VERIFY IF OTHER DTC IS DISPLAYED • Perform the DTC inspection. (See DTC INSPECTION.) • Are any other DTCs displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting.
Repair completion verification 2		No	DTC troubleshooting completed.