Will not auto change gears allowing to accelerate

2004 KIA SORENTO

255,000 MILES • 3.5L • 6 CYL • 2WD • AUTOMATIC

BIGMIKE2803$$

MEMBER
1 POST

I worked on my vehicle listed above myself, i replaced almost everything. however, I am having trouble with auto gear changing. It starts, runs and drives fine, but will not auto change gears allowing to accelerate. Help

Oct 28, 2020 at 11:22 AM

ASEMASTER6371

✓ASE Certified Mechanic
52,796 POSTS

Good afternoon,

The throttle position sensor is a key sensor for transmission shifting. I attached the flow chart for you to follow for this.

https://www.2carpros.com/articles/automatic-transmission-problems

Line pressure is also key to the transmission to work. I attached the chart for the proper pressures.

You will need to rent a gauge for the testing.

If both of these are okay, then it has an internal failure.

Roy

Throttle Position Sensor (TPS)

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The TPS is a variable resistor type that rotates with the throttle shaft to sense the throttle valve angle. As the throttle shaft rotates, the output voltage of the TPS changes. The ECU detects the throttle valve opening based on this voltage change.

Circuit Diagram
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Harness Inspection Procedures
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TROUBLESHOOTING HINTS

The TPS signal is important in the control of the automatic transaxle. Shift shock and other trouble will occur if the sensor is faulty.

Images (Click to enlarge)

Professional Diagram for 2CarPros Members
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Oct 28, 2020 at 1:27 PM