P0641

P0641

General Description
The ECM provides a 5 volt reference voltage to Throttle Position Sensor 1(TPS1). The ECM monitors reference voltage deviation from the power supply circuit of the sensors.

DTC Description
Checking the voltage from sensor power supply every 1.87 sec. under detecting condition, if the value within detecting condition lasts for more than 0.2 sec., PCM sets P0641. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

Schematic Diagram:

Monitor DTC Status
1. Check DTC Status
1. Connect scantool to Data Link Connector(DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes(DTCs)" mode, and then Press F5(INFO) to check DTC's information from the DTCs menu
4. Read "DTC Status" parameter.






5. Is parameter displayed "Present fault"?

YES
a. Go to "Terminal and Connector inspection" procedure.

NO
a. Fault is intermittent caused by poor contact in the sensor's and/or PCM's connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.

Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. 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 - Repair as necessary and go to "Verification of Vehicle Repair" procedure

NO - Go to "Power Circuit Inspection" procedure.

Power Supply Circuit Inspection
1. Check voltage
1. IG "OFF".
2. Disconnect TPS connector.
3. IG "ON" and ENG "OFF"
4. Measure the voltage between terminal 4 of TPS harness connector and chassis ground.

Specification : Approx. 5 V






5. Is the measured voltage within specification ?

YES - Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and go to "Verification of Vehicle Repair" procedure.

NO - Go to "Check short in power harness" as follows.

2. Check short in power harness
1. IG "OFF".
2. Disconnect TPS connector and PCM connector.
3. Measure the resistance between terminal 4 and 5 of TPS harness connector.
4. Measure the resistance between terminal 4 and 8 of TPS harness connector.
5. Measure the resistance between terminal 4 and 1 of TPS harness connector.
6. Measure the resistance between terminal 4 and 6 of TPS harness connector.

Specification : Infinite






7. Is the measured resistance within specification ?

YES
- Substitute with a known - good PCM and check for proper operation.
- If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

NO - Repair Short in power circuit and go to "Verification of Vehicle Repair" procedure.

- Procedure of ETS Initialization
1. Erase the trouble codes on PCM
2. Turn the ignition key off and maintain this condition until the main relay is turned off.(It will take 10 second)
3. Turn ignition key on more than 1 second to record the throttle motor position on the EEPROM

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Press F5(INFO) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions
3. Read "DTC Status" parameter
4. Is parameter displayed "History(Not Present) fault"?

YES - System performing to specification at this time. Clear the DTC

NO - Go to the applicable troubleshooting procedure.