2001 Sonata P0118/P0720 changed sensors, help needed!!!!

DanaliHD · 06-07-2009, 01:41 AM

My mother's 2001 Sonata had a check engine light. I hooked up my scan tool and found P0118 and P0720. I purchased a new coolant temp sensor and new Output speed sensor and tonight I changed them both. I erased the codes and immediately the P0118 code came back.

She drove to the gas station a mile away and said the check engine light came back on and the car got stuck in 2nd gear and when it shifted it shifted hard enough to squeel the tires. Now both codes are back along with P1529.

Now what?

note** I did not disconnect the battery before changing the sensors which was probably stupid.

J0eFr0 · 06-07-2009, 08:27 PM

P0118: The ECM will set P0118 and the Malfunction Indicator Lamp (MIL) will turn on if the ECT sensor reports a temperature above 284°F (140°C) for 0.2 seconds during two driving cycles.
Here is how to test it:

P0720: Means there is no signal coming from the Output speed sensor, you should replace the sensor. Then drive the vehicle for at least two key-on to key-off driving cycles.

If it is still on after that:
Use a DVOM to check the resistance of the wiring between the TCM and the output sensor.

If its more than 1 ohm resistance you have a problem in the wiring between the TCM and the output speed sensor.

If its less than 1 ohm, replace the TCM.

P1529: TCM Request for MIL On/Freeze Frame to ECM via CAN

Thats just the TCM telling the ECU to turn on the check engine light for code P0720

DanaliHD · 06-07-2009, 08:41 PM

ok, the P0118 is gone. changed the sensor last night. I also changed the output speed sensor last night but it was after that that the trans went into failsafe.

Just a few minutes ago I unhooked the battery for 10min or so, hooked it back up and checked for codes. I had none. Drove it down the road, took forever to shift from 1-2 and when it did it SLAMMED into gear and stayed there. SES light (mil) light came back on and the 2 trans codes came back.

When swapping out the sensor last night my brother snapped the little tab off the wiring connector by accident. it is plugged in properly(i think) but it doesn't click/lock like it is supposed to.

Where is the TCM?

DanaliHD · 06-08-2009, 11:38 AM

it works. looks like the sensor wasn't plugged in all the way.

J0eFr0 · 06-09-2009, 01:23 AM

sweet, nice and simple fix

DanaliHD · 06-19-2009, 10:22 AM

Damn it!!! Car has been sitting for over a week and the trans issue came back. Grrrrrrrrr

DanaliHD · 06-22-2009, 11:58 AM

for the love of god! Ok, fixed the P0720 issue last week. No problem. Drove the car probably 100mi. Made 5-6 stops etc. Ran perfect. Car sat for 10 days. My brother came to pick it up to bring it back to my mother and he said it barely started and wouldn't go over 30mph, sputtering etc. I figured it was the same issue.

NOPE. Put my scanner on it today and had P0335 crankshaft sensor error. WTF? It was just sitting there. Anywho, somehow got it in the garage this morning, pulled the battery, pulled the airbox, checked the output speed sensor, looked good. Put everything back together, fired it up, got the code again. Deleted the code, tried to start, got the code. Deleted it again, fired it up and it seemed good. Let it run for 10min, idle was smooth. Shut it down, fired it back up, and same thing. Didn't want to start, sputtering. got it started, gave it some gas and it was sputting like crazy.

Any ideas? Maf is hooked up properly, airbox/tube in tact. only wires I touched were the harness to the output speed sensor and obviously the +/- battery cables.

rocconi · 06-22-2009, 01:15 PM

"Put my scanner on it today and had P0335 crankshaft sensor error."

Have you replaced the Crankshaft position sensor? This is a different sensor than the Output Speed Sensor.

DanaliHD · 06-22-2009, 01:18 PM

Quote:

Originally Posted by rocconi

"Put my scanner on it today and had P0335 crankshaft sensor error."

Have you replaced the Crankshaft position sensor? This is a different sensor than the Output Speed Sensor.

No, no idea even where it is. I'm thinking it is maybe NOT the sensor. What are the odds that 3 sensors would go bad all at once? Hmm.

rocconi · 06-22-2009, 02:19 PM

Well I would at least take it out and measure the resistance and see that it is in range. Also, I would try heating it with hot water while it is in a plastic bag to about 140 F and take a reading. Then I would put it in the freezer and take another reading. I would be looking for an intermittent open. Check the connectors for corrosion while your at it.