P1178
P1178 ETS Relay-MAL
Component Location
General Description
The ETS(Electronic Throttle System) is the throttle body whose throttle angle is controlled by control module. It consists of ETS unit, ETS-motor, Accelerator Position Sensor (APS), Throttle Position Sensor (TPS) and Limp home valve. The PCM sends throttle valve target opening value to ETS unit after calculating from signals such as APS and other input values. The ETS unit controls ETS motor to meet PCM's throttle valve target opening value. ETS motor's rotor rotates 780° from the the closed throttle valve to the wide open throttle valve and ETS motor controls the opening angle of throttle valve with 26 patterns; motor's rotor rotates 30° per one pattern.
DTC Description
DTC P1178 is set if there is an open in power line of ETS motor.
DTC Detecting Condition
Specification
Schematic Diagram
Signal Waveform
Monitor Scantool Data
1. Connect scantool to Data Link Connector (DLC).
2. Ignition "ON" & Engine "OFF".
3. Select "ACTUATION TEST" on scantool.
4. Using the scantool, operate ETS motor by force
5. Does the ETS motor operate well?
YES
1) Fault is intermittent caused by poor contact in the related sensor's and/or ETS unit connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "W/Harness Inspection" procedure
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES
1) Repair as necessary and then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Power Circuit Inspection" procedure.
Power Supply Circuit Inspection
Check Fuses for Open
1. Ignition "ON" & Engine "OFF".
2. Measure voltage in fuses (15A O2 SNSR,20A ETS)
A. Specification: Approx. B+
3. Is Voltage within specifications?
YES
1) Go to "Check Power to ETS Relay" as below
NO
1) Check blown fuses. Replace as necessary and go to "Verification of Vehicle Repair" procedure.
Check Power to ETS Relay
1. Ignition "ON" & Engine "OFF".
2. Disconnect ETS relay.
3. Measure voltage between terminal "1 " of the ETS relay harness connector and chassis ground
4. Measure voltage between terminal "4 " of the ETS relay harness connector and chassis ground
A. Specification: Approx. B+
5. Is the voltage within specifications?
YES
1) Go to "Check voltage in terminal 2 of ETS relay" as below.
NO
1) Check for open in power supply harness. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check Voltage in Terminal 2 of ETS Relay
1. Ignition "ON" & Engine "OFF".
2. Connect ETS relay
3. Measure the voltage between terminal "2" of ETS relay and chassis ground.
A. Specification: Approx. B+
4. Is the voltage within specifications?
YES
1) Go to "Check Open in Line" as below.
NO
1) Go to "Ground Circuit Inspection" procedure.
Check for Open in Harness
1. Ignition "OFF".
2. Disconnect ETS relay.
3. Measure resistance between terminals "2" of ETS relay harness and terminal "2" of ETS unit harness connector.
A. Specification: Approx. 0 ohm
Ground Circuit inspection
1. Ignition "ON" & Engine "OFF".
2. Connect ETS relay
3. Short terminal "5" of ETS relay harness connector to chassis ground.
4. Measure voltage between terminal "2" of ETS relay harness connector and chassis ground.
A. Specification: Approx. B+
5. Is voltage within specifications?
YES
1) Substitute with a known-good PCM and check for proper operation. If the problem is corrected, replace PCM and then go to "Verification of Vehicle Repair" procedure.
NO
1) Go to "Component Inspection" procedure.
Component Inspection
Check Resistance of ETS relay
1. Ignition "OFF".
2. Disconnect ETS motor connector
3. Measure resistance between terminals "1" and "5" of ETS relay.
A. Specification: 75 ~ 115 ohms
4. Is the ETS relay resistance within specifications?
YES
1) Substitute with a known-good PCM or ETS unit and check for proper operation. If the problem is corrected, replace PCM or ETS unit and then go to "Verification of Vehicle Repair" procedure.
If ETS unit needs to be replaced, do initialization after it is replaced.
NO
1) Check ETS relay for contamination,deterioration, or damage. Substitute with a known-good ETS relay and check for proper operation. If the problem is corrected, replace ETS relay and then do initialization. And go to "Verification of Vehicle Repair" procedure.
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code (DTC) which has been diagnosed.
2. Using a Scantool, Clear DTC.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as "Complete"
5. Are any DTCs present ?
YES
1) Go to the applicable troubleshooting procedure.
NO
1) System is performing to specification at this time.