Jun 082016

Code P2251 Hyundai ElantraI have Engine code p2251 on my 2004 Hyundai Elantra, what could be the cause? I also have codes po507 po301


Engine Code P2251 HYUNDAI – O2 Sensor Reference Ground Circuit/Open Bank 1 Sensor 1

The linear O2 sensor is mounted on the front side of the Catalytic Converter (warm-up catalytic converter) or in the front exhaust pipe. It detects a wide range of air/fuel ratios in the exhaust gas from the rich to lean regions. This linear O2 sensor produces a current that corresponds to a specific air/fuel ratio. The Powertrain Control Module (PCM) monitors this signal and determines whether the air/fuel mixture is rich or lean. The PCM constantly monitors the linear O2 sensor and increases or decreases the fuel injection duration using this signal. This is called closed-loop fuel control operation.

Possible causes
– Faulty Heated Oxygen Sensor Bank 1 Sensor 1
– Heated Oxygen Sensor Bank 1 Sensor 1 harness is open or shorted
– Heated Oxygen Sensor Bank 1 Sensor 1 circuit poor electrical connection
P2251 Hyundai Description


Code P0507 – Idle Control System RPM Higher Than Expected
If there are no intake leaks, clean throttle body, adjust engine idle and erase engine code. If the code comes back you may have to replaced the Electric Throttle Control Actuator (Motor) to repair the problem.

Possible causes
– Dirty throttle body
– Electric throttle control actuator mis-adjusted or damaged
– Faulty Electric throttle control actuator
– Intake air leak
– Poor electrical connection to the Intake Air Control (IAC) valve

Code P0301 – Cylinder 1 Misfire Detected

The P0301 code means that the cylinder 1 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 1. If the problem persist more tests needs to be done to diagnose problem.

Possible causes
– Faulty spark plug 1
– Clogged or faulty fuel injector 1
– Faulty ignition coil 1
– Fuel injector 1 harness is open or shorted
– Fuel injector 1 circuit poor electrical connection
– Ignition coil 1 harness is open or shorted
– Ignition coil 1 circuit poor electrical connection
– Insufficient cylinder 1 compression
– Incorrect fuel pressure
– Intake air leak



Jun 012016

My brake lights will not turn on, I have changed the light bulbs, checked the fuses. My third one is functioning properly, so I know it’s not the brake lamp switch. Just not sure what else to do.


You are correct, since the third brake light is coming on it leaves you with either a wiring issue, socket issue or bulb issue. Use the wiring diagram provided to help assist you in tracing the problem.


Jun 012016

2013 Hyundai AccentEvery time I turn on my right blinker when my headlights are on, the brights also turn on, only when I turn on my right blinker. Help me! Thanks.


Most common reason would be a faulty Multi-Function Switch(turn signal lever)

May 022016

Change Transmission FluidI need to change transmission fluid on my 2003 Hyundai Sante Fe 3.5L. It has a plug at the bottom of the transmission. Do I still have to change the filter. The pan is side mounted. I purchased a filter and it resembles a oil filter. Now if I have to change the filter will it be located under the transmission pan as other vehicles. And what size metric wrench do I need to remove the transmission plug


It is recommended to change transmission fluid and filter every 105,000 miles under normal conditions and every 30,000 miles under severe conditions(heavy towing). Fluid level should be checked every 12 months or 15,000 miles.

The Filter is mounted externally, not under the pan. The removal of the side mounted transmission pan is not necessary. Not sure of the exact size bolt. If I had to guess it would be a 13mm or 15mm. You may use a bolt measuring chart to help identify the size.



Apr 022016

2001 Hyundai Accent
how and where do I adjust the headlight??

Headlight Adjustment may be required from time to time. If so, pop the hood and you should see two dials (hex shaped plastic screws) on each of the headlight assemblies. One is for your high beams and one is for your low beams. You’ll need to measure from the ground up to the center of your bulb and make that marking on the wall for each of your bulbs (so four marks). Then park about 30 feet away from the wall (make sure you’re on a level surface that’s level with the wall base. If the light says VOR, then the top of the brightest area of the light should line up with the mark. if it says VOL, then the top of the brightest area of the light should line up two inches below the mark.
Headlight Adjustment
Here’s the Accent headlight. The yellow arrow is vertical and the red is horizontal. The headlight is upside down.

How to Adjust Headlights

Headlights must be properly aimed to provide the best road illumination. The lights should be checked for proper aim and adjusted as necessary. Certain state and local authorities have requirements for headlight aim; these should be checked before adjustment is made.

When adjusted properly, the lights should not glare in oncoming traffic’s windshields, nor should they illuminate the passenger compartment of vehicles driving in front of you. These adjustments are rough and should always be fine-tuned by a repair shop that is equipped with approved, headlight aiming tools. Improper adjustments may be both dangerous and illegal. Temporary headlight adjustment may be made using a wall, using the following procedure, or on the rear of another vehicle.

When headlights are replaced or any time front-end work is performed on your vehicle, the headlights should be accurately aimed by a qualified auto repair shop using the proper equipment. Headlights not properly aimed can make it virtually impossible to see and may blind other drivers on the road, causing injury or death. The following procedure is a temporary fix, until you can take your vehicle to a repair shop for a proper adjustment.

Note: Because the composite headlight assembly is bolted into position, no adjustment should be necessary or possible. Some applications, however, may be bolted to an adjuster plate or may be retained by adjusting screws. If so, follow this procedure when adjusting the lights, but always have the adjustment checked by a qualified shop.

For most of the vehicles, horizontal and vertical aiming of each sealed beam unit is provided by two adjusting screws that move the retaining ring and adjusting plate against the tension of a spring. There are no adjustments for focus; this is done during headlight manufacturing.

Before removing a headlight bulb or disturbing the headlamp in any way, note the current settings in order to ease headlight adjustment upon reassembly. If the high or low beam setting of the old lamp still works, this can be done using the wall of a garage or a building:
1.Park the vehicle on a level-surface, with the fuel tank about 1/2 full and with the vehicle empty of all extra cargo (unless normally carried)

◦The vehicle should be facing a wall that is no less than six feet (1.8m) high and 12 feet (3.7m) wide
◦The front of the vehicle should be about 25 feet from the wall
◦If aiming is to be performed outdoors, wait until dusk to properly see the headlight beams on the wall
◦If done in a garage, darken the area around the wall as much as possible by closing shades or hanging cloth over windows

2.Turn the headlights ON
3.Mark the wall at the center of each light’s low beam
4.Turn on the high beams and mark the center of each headlight’s high beam.

◦A short length of masking tape that is visible from the front of the vehicle may be used.

Note: Although marking all four positions is advisable, marking one position from each light should be sufficient.
Low-beam headlight pattern alignment
how to adjust headlights
High-beam headlight pattern alignment
headlight adjustment chart
5.Perform any necessary repairs ◦Make sure the vehicle is not moved, or is returned to the exact spot from where the lights were marked

6.Turn the headlights ON
7.Adjust the beams to match the marks on the wall

Have the headlight adjustment checked as soon as possible by a qualified repair shop.

Halogen bulbs contain a gas under pressure. Handling a bulb improperly could cause it to shatter into flying glass fragments.
•To help avoid personal injury:
•Turn off the headlamp switch and allow the bulb to cool before changing bulbs. Leave the headlamp switch off until the bulb change is complete.
•Always wear eye protection when changing a halogen bulb.
•Handle the bulb only by its base. Avoid touching the glass.
•Do not drop or scratch the bulb. Keep moisture away.
•Place the used bulb in the new bulb’s carton and dispose of it properly. Keep halogen bulbs out of the reach of children

Mar 292016

1997 Hyundai ElantraMy Hyundai Elantra has an intermittent flat spot. Engine cylinder head repairs done, oil change, oil filter change, plugs, ht leads, fuel filter. No vacuum leaks found. injector spray pattern good. Your assistance will be greatly appreciated


Being intermittent can cause you to want to pull your hair out at times. It causes things on your Hyundai Elantra to test good one time and bad at others. Ultimately making it more difficult to narrow down. In most cases you can continue to drive the car until the problem becomes more frequent.

Hyundai Elantra intermittent flat spot

My thoughts on this particular instance lean toward the head repairs and why you might need head repairs done in the first place. I am guessing the timing belt broke and damaged the valves. This is common enough, but maybe not all the valves were replaced and one is still slightly bent. As it moves around it will cause a slight flat spot as the valve cannot seat properly.

Mar 042016

2004 Hyundai Sonata
Having problem with my heater controls inside my car but the AC doesn’t work with the controls either. So I’m thinking its a short in the dashboard control panel switches but wanted to make sure before I pull the dash apart.

I am thinking if it doesn’t blow air out the dash at all on any speed setting that you have a possible blower motor issue (check the “blower fuse” located in the under hood fuse block). Only blows on High speed would be a blower motor resistor issue. Stuck on hot or cold would be an actuator issue. Stuck on defrost/dash/floor would also be an actuator issue. No signal going tot he actuators would be a control panel issue. If you decide to dig into the dash these instructions may help save you a little time.

Control Panel Removal & Installation

  1. Remove the front console cover.
  2. Remove the screw, and detach the clips.
  3. Disconnect the following items to remove the center fascia panel (A).
    • Hazard warning lamp connector (B).
    • Rear defroster connector (D).
    • Windshield deicer connector (C).
    • Front fog lamp connector (E).
      dash control panel removal diagram

      Control panel connectors diagram

  4. Remove the audio assembly.
  5. Loosen the screws.
  6. Remove the heater control unit (A).
    Heater control panel unit diagram

    Heater control unit diagram

  7. Installation is the reverse of removal.

    Make sure all the connectors are plugged in properly.

Air conditioning troubleshooting

Feb 262016

Hyundai Accent
Drove through water, car stalled. Air filter was soaking wet. We replaced air filter and changed the oil (no water in oil) but car is ticking, what should I do?