P0720, P1529 & P1134

[r1981474]

I have a 2001 Sonata GLS V6. Just recently I got a CEL and the following three codes appeared:

P0720 - OUTPUT SPEED SENSOR - CIRCUIT MALFUNCTION
P1529 - IDLE SPEED CONTROL - AUX INPUTS
P1134 - MANUFACTURER CONTROL - FUEL AIR METERING

From disucssions and forums, I believe if I replace the Output Speed Sensor and the O2 sensor behind the firewall, I should be set. Is that correct?

Someone told me that these codes were common on the model year. I suppose that is so...

If anyone has any comments regarding this message, I would greatly appreciate it :).

[only1db]

there is a reprogram for the above code...the speed sensor needs to be replaced...read on for futher explanation.


here is the reprogram and subsequent replacement of both upstream 02 sensors

tsb # 01-36-023...if the reprogram has already been done then the consequential 02 sensor will need to be replace...

btw...the 1529 is a code to the ecm to illuminate the MIL...pretty much a code to tell the compute to throw a check engine light.

here is the TSB # for the p0720 code...01-40-005...pretty much says to replace the output speed sensor

i'm assuming that he car is in failsafe...it should be if its throwing that code (meaning that the car is stuck in third gear and reverse engages really rough)

[r1981474]

Well, I put in a need output speed sensor and after that, the car's speedometer will increase, the tachometer will slowly reach 4000 rpm's and the car will kick back really bad. Then the tach will continue to go up slowly with no shift to next gear.

According to Hyundai's TSB for that issue, the TCM needs to be replaced also. Why is that?

BTW, I put in the old sensor and it shifts at 3000 rpm's.

Since the reprogramming was done, does the consequential O2 sensor mean only the one sensor setting the computer off?

Is the O2 sensor is pulls the P1134 code located behind the firewall?

Does hyundai's have tendency to think that the fuel tank is filled eventhough it is partially empty? Someone told me about a Purve Valve Cansiter.

[only1db]

yeah only replace bank 1 sensor 1....if i remember correctly you can get it from the bottom of the car easy...although thats with it up on he lift and i can reach up.


the purge valve is used to regulate the fumes and pressure in the gas tank...it has nothing to do with the reading of how much fuel there is...that comes down to the fuel sender.

whats the issue with that?