2000 Hyundai Sonata couple problems.

Hi arash123,

Thank you for the donation.

There are 4 O2 sensors in your vehicle and it can be a DIY job but access to some are not that easy.

Fans motors are not universal and there are various types. You need to get the one that fits and the fan blades can be reused.

When you need to judder the fan into motion, it indicates the carbon brushes are running out and it is a matter of time before it fails completely.

What is/are the trouble codes that you are getting?

When a scan is done, trouble codes would be retrieved. I requested for the trouble codes but they were not provided.

Right side is the condenser fan while left is the radiator fan. If only one is faulty, you need not replace both.

Before proceeding further, check if the TPS and ISC connectors had been mistakenly swapped. ISC connector should have the following wire colors :
1. Orange/black
2. Blue
3. Pink.

Throttle Position Sensor has :
1. Green/White.
2. Blue
3. Black/White

P0134 = Bank 1 sensor 1 = on bottom of right exhaust manifold. Check the wiring connections first.

Here are diagnostic procedures.

DTC P0133, P0134: FRONT HO2S CIRCUIT SLOW RESPONSE OR NO ACTIVITY DETECTED
NOTE:
There is a Heated Oxygen Sensor (HO2S) before and one after the catalytic converter. The front HO2S measures oxygen content of exhaust gases and is used to control air fuel mixture. The rear HO2S is used to determine the efficiency of the catalytic converter. ECM calculates catalytic converter efficiency by comparing front and rear HO2S signals.

Failure Conditions
1. ECM will set DTC P0133 and illuminate MIL when ECM does not sense the following condition during 2 drive cycles:
" Over a period of 2.3 seconds, ECM must detect 10 cycles from lean-to-rich or rich-to-lean when engine speed is 2000-3000 RPM, engine load range is 1.9-4.7 milliseconds, catalytic converter temperature is more than 673 °F (356 °C) and system is in closed loop.
" ECM must make some correction in air fuel ratio within 133 seconds when engine speed is 1600-2400 RPM, engine load range is 1.35-1.80 milliseconds, catalytic converter temperature is more than 673 °F (356 °C) and system is in closed loop.
"Â DTC P0133 indicates engine air fuel ratio is not being adjusted by front HO2S signal or ECM as expected, or as often as expected when engine is at normal operating temperature or normal use.

2. ECM will check rear HO2S operation after engine has operated for 3 minutes and 20 seconds. ECM will measure front HO2S output voltage when rear HO2S output voltage is more than 500 mV (0.5 volt). ECM will set DTC P0134 and illuminate MIL, if during 2 drive cycles the front HO2S output voltage is not 400-600 mV (0.4-0.6 volt) for 5 seconds. This DTC indicates front HO2S is not active within expected range once the engine is at normal operating temperature.

Test Procedures

1. Turn ignition on and connect scan tool to data link connector. Verify DTC P0133 or P0134 is set. If DTC P0135 is also set, repair DTC P0135 first.

2. Start engine and allow to idle at normal operating temperature. Increase engine speed to 4000 RPM. Using scan tool, monitor HO2S voltage. If voltage is zero volts, go to next step. If voltage is constant and approximately 450 mV (0.45 volt), go to step 4. If voltage varies, but stays less than 500 mV (0.5 volt - lean), go to step 6. If voltage varies, but stays more
than 500 mV (0.5 volt - rich), go to step 7. If voltage varies between 100 and 900 mV (0.1-0.9 volt), go to step 8. If voltage is constant and approximately 5.0 volts or 12.0 volts, repair short to voltage in wiring harness. When repairs are completed, clear DTCs and
verify HO2S operation.

3. Disconnect front HO2S 4-pin connector. If DTC P0133 is set, voltage displayed on scan tool should be approximately 450 mV (0.45 volt). If DTC P0134 is set, voltage displayed on scan tool should be approximately 500 mV (0.5 volt). If voltage is as specified, replace suspect HO2S. If voltage is not as specified, repair short to ground in Yellow wire between HO2S connector terminal No. 1 and ECM 88-pin connector terminal No. 12. When repairs are completed, clear DTCs and verify HO2S operation.

4. While engine is operating, backprobe between HO2S 4-pin connector terminals No. 1 and 2, and measure voltage. If voltage changes from less than 500 mV (0.5 volt) to more than 500 mV (0.5 volt), go to next step. If voltage does not change, replace HO2S. When repairs are completed, clear DTCs and verify HO2S operation.

5. Turn ignition off. Disconnect front HO2S 4-pin connector and ECM 88-pin connector. Using a jumper wire, connect HO2S connector terminal No. 1 to ground. Measure resistance between ground and ECM connector terminal No. 12. If resistance is one ohm or less, ensure ECM connector terminals are clean and tight. If PCM connector are okay, replace front HO2S. Clear DTCs and verify HO2S operation. If problem persists, replace ECM. If resistance is more than one ohm, repair open or cause of high resistance in circuit between HO2S and ECM. When repairs are completed, clear DTCs and verify HO2S operation.

6. If voltage varies and is always less than 500 mV (0.5 volt - lean), check air inlet downstream of Mass Airflow (MAF) sensor for leaks or damage. Check exhaust manifold for cracks or leaks. If any leaks or damage is found perform repairs as necessary. If no leaks or damage is found, go to next step.

7. Perform fuel pressure inspection. If fuel pressure is within specification and no pressure leak-down is detected, go to next step. If fuel pressure is not as specified, repair fuel system as necessary. When repairs are completed, clear DTCs and verify HO2S
operation.

8. Turn ignition off. Disconnect ignition coil connector. Connect voltmeter between negative battery cable and cable attachment located on engine. Measure voltage drop across negative battery cable while cranking engine. If voltage drop is less than 0.5 volt, go to next step. If voltage drop is more than 0.5 volt, replace negative battery cable. When repairs are completed, clear DTCs and verify HO2S operation.

8. Disconnect negative battery cable and measure resistance between generator housing and engine ground point. If resistance is one ohm or less, go to next step. If resistance is more than one ohm, clean mating surfaces of generator housing and engine. When repairs are completed, clear DTCs and verify HO2S operation.

10. If MIL is illuminating intermittently and DTC P0133 is set, problem is most likely a poor ground circuit. Clean negative battery terminal and engine ground. In addition, clean mating surfaces of generator housing and engine. If MIL was illuminated and DTC P0133 or P0134 is set, replace front HO2S. When repairs are completed, clear DTCs and verify HO2S operation.

You should not have attempted to open the the radiator cap when the coolant is hot. It should be done on a cold engine.

When the coolant have heated up and there are air trapped in system, the coolant would bubble out.

It could mean a bad head gasket as well.

The radiator fan working when you vibrate it is because the cabon brushes are almost worn and have intermittent vontact. It would fail completely sooner or later. As to the condenser fan, it could be faulty. One way of test it is to disconnect the connector and apply direct battery voltage to 1 terminal and grounding the other.

The upper hose would be hot when coolant is being sent to the radiator to be cooled. If the lower hose is hot, then the radiator could be partially clogged reducing its cooling efficiency. With only one fan working, the cooling efficiency would be lower and prolonged starting of the engine could cause the temperature to increase gradually.

If the TPS is removed and installed, it has to be calibrated/adjusted correctly.

Sonata (2.5L)
1. Turn ignition off. Disconnect TP sensor 3-pin connector. Measure resistance between TP sensor terminals No. 2 (sensor ground) and No. 3 (sensor 5-volt supply). See Fig. 1 . Standard resistance value should be 3500-6500 ohms. If resistance is not as specified, replace TP sensor. If resistance is as specified, go to next step.

2. Measure resistance between TP sensor terminals No. 1 (sensor signal) and No. 2 (sensor ground). Open throttle slowly from idle position to wide-open throttle position. Resistance should change smoothly in proportion to the throttle valve opening. If resistance changes smoothly, go to next step. If resistance does not change smoothly, replace TP sensor.

3. Ensure basic idle speed is correct. Turn ignition off. Disconnect TP sensor 3-pin connector. Using jumper wires, connector an ohmmeter between TP sensor terminals No. 1 (sensor signal) and No. 2 (sensor ground). Insert a 0.0256" (0.65 mm) feeler gauge between throttle level and throttle stop.

4. Loosen TP sensor mounting screws and rotate sensor fully counterclockwise. Ensure continuity exists between sensor terminals No. 1 and 2. Slowly turn sensor clockwise until continuity does not exist between sensor terminals No. 1 and 2. Tighten sensor mounting
screws.

5. Reconnect TP sensor connector. Using a voltmeter, backprobe sensor connector terminals No. 1 (sensor signal) and No. 3 (5-volt supply). Turn ignition on, and measure TP sensor voltage. Voltage should be 250-800 millivolts. If voltage is not as specified, ensure TP sensor adjustment is correct and wiring harness is okay. Remove feeler gauge, and turn ignition off. Perform additional repairs as necessary.

Thank you for the input and glad to know you have fixed the problem.

I would never recommend replacing parts till it has been confirmed it is faulty. To use a trial and error method is costly and most of the time a waste of resources.

Thank you for using 2carpros and have a nice day.

No problem, we can continue from here anytime.

If it is a filter, it should be occurring at all speeds under accelerating condition.

Try shifting to 3 and see if the same conditions occurs. Just want to confirm it is speed and not engine rpm related.

If it is speed related, it could be the trans that is causing the jerking.

We still do not know the actual problem so we need to figure it out.

Problem could also be spark related as the hesitation could be misfiring which is not registered in the PCM because it does not occur all the time. A fuel pressure loss can also cause the problem.

If it is a transmission fault, a flush might not work, unless it is due to the fluid condition.

Try to note the engine rpm and gear position when problem occurs.

If the catalytic converter is good and the O2 sensors are out of specs, it can cause the hesitation. Since the smog test failed and the O2 sensors are deemed bad, you have no other option except to replace the O2 sensors and hope that they are the only cause of the hesitation.

They should at least get you to pass smog test.