2003 Toyota 4RUNNER electrical problems

Filed Oct 29, 2025 · Electrical · 306,000 miles · CA

Odometer Fraud. The contact investigated a 2003 Toyota 4 Runner. The contact stated that during the investigation, he discovered a fraudulent scheme of approximately 15 vehicles with odometer fraud. The contact stated that the suspects targeted Facebook Marketplace victims by spraying oil on the engine prior to test-driving the vehicle, and when the vehicle began smoking, the suspects would ask for a discount for the vehicle. The contact added that after the vehicle was purchased, the odometer was rolled back and the vehicle was resold. The vehicle was a private sale. At the time of purchase, the vehicle mileage was 150,000, and at the time of the vehicle being sold, it was discovered that the mileage was 306,000.

Filed Feb 5, 2021 · Brakes, Electrical · 200,000 miles · NJ

The rear tire assembly ripped loose from its mounts under normal driving conditions..a loud clunk noise....then .brakes were lost and the electrical system showed warning lights on dash board...car is not drivable...massive rust at failure points

Filed Mar 30, 2017 · Electrical · 170,000 miles · NC

Tl* the contact owns a 2003 toyota 4runner. The contact stated that while the vehicle was parked, the contact noted that there were cracks in the dashboard near the air vents. The vehicle was taken to a dealer where it was diagnosed that the dashboard was cracking and needed to be replaced. The manufacturer also sent a letter asking owners to take the vehicle to a dealer to have the dashboard inspected however, the dealer stated that the repair part was not available. There was no recall on the failure. The vehicle was not repaired. The approximate failure mileage was 170,000.

Filed Feb 1, 2016 · Electrical, Fuel system · AR

My 2003 toyota had emissions issues in that all four oxygen sensors would fail quickly. It took me two years and lots of money later to determine that the cause of this is because transmission fluid is wicking its way through the transmission solenoid harness all the way to the ecu and once there because of the way the ecu is mounted gets into all of the other wiring harnesses of just about every other sensor. I went to toyota and the first technician never heard that happening before but another overheard our conversation and said "I bet you have a 4runner" so yeah its happened to others. They wanted nearly $4500 to fix the issue. New engine wiring harness $1500-$2000 and another $1000 for the labor and the rest of the estimate is for other parts not specified. Their solution is to cut the wire below the transmission wiring harness connector then splice and solder but I would have to replace nearly all the critical wiring in that car. I cant give an exact date on when it started going wrong but I can look at the service history on the toyota owner's website and give you this timeline. 0-89,997 - no, issues with emissions or electrical systems. 89,997mi - 90k service done - transmission fluid change w/flush done at dealer. 98,152mi - car reporting lean codes, dealer replaces maf sensor. 100,117 - car reporting lean codes, dealer replaces o2 sensor and a/f sensor bank 2 position 1 & 2 105,312 - car reporting lean codes, dealer replaces bank 1 position 1 a/f sensor and maf sensor again. Total cost $798.76. There are more but I have character limits. I will say this though that the problem should have been obvious because you can clearly see the fluid when you unplug the o2 sensor from the harness but toyota was content charging me $500-$700 every 10k miles without actually fixing it. Car still remained functional but ruined fuel economy.

Filed May 26, 2015 · Electrical · 168,040 miles · TX

Upon starting vehicle, gas gauge and tachometer did not work. Turned ignition off then restarted and gas gauge fluctuated and finally responded, but no response from tachometer. After driving vehicle with air on, stopped at store then started vehicle and all gauges worked. This has happened quite often since it is getting warm. I have read blogs where other owners of the sport model are experiencing the same issue with the cluster failing. Some have tried to get repaired and that's a 50/50 shot. The only way to resolve is to replace cluster at $300.00 used without labor and an extra fee of $100.00 to calibrate mileage. Toyota is aware of issue, but fails to respond.

Filed Aug 27, 2012 · Acceleration, Brakes · 50,000 miles · MD

On approximately february 28, 2012, the ABS/trac control/vsc lights came on and remained lit on my 2003 toyota 4runner. I called the dealership and they said to bring it in right away. They diagnosed the car and came up with "no sensor reading?. It cost me $150 for the diagnostic test. I picked up the car and a few weeks later I brought it back for the same problem. The computer then indicated that there was a faulty o2 sensor which they replaced my cost was over $650. The next week the lights came on again. The dealership kept the car for a few days but later reported that they could not duplicate the problem. They told me that I should wait until it got worse and bring it back. I suffered with this problem for months. I say suffered because when I was in park and these lights came on, I could not shift out of park. The lights would eventually go away and allow me to drive. On 8/24 the problem became worse. I could not shift my car out of park for more than 15 minutes on over 10 different occasions. The warning lights remained lit almost constantly over 3 days. When I called to return the car to the dealership on 8/27, the service person said that she thought there was a recall associated with that issue, but then told me that there was not. Later that day, they called and said that they again could not replicate the problem. After a quick internet search, it seems that many people have had the same experience that I have had on various toyota vehicles. I feel an investigation is appropriate in this instance.

Filed Mar 1, 2011 · Acceleration, Brakes · 12,000 miles · CO

The vehicle would rev itself up to a high RPM, from a stopped position when I stepped on the gas the vehicle would go in reverse. The dealership eventually replaced the transmission only after the manager borrowed it overnight and experienced it himself, but I have noticed the problem beginning again. Another problem is the radiator leaking and needed to be replaced (I was told it had the wrong kind of antifreeze; it was green and it needs a red kind???). When replacing this I was notified that my front brakes were paper thin and needed to be replaced this repair cost me almost $2000. Another problem is the rear window trim has shrunk. I also had the sunroof replaced after owning the vehicle less than two years. The brake light on the rear hatch does not work as well as the rear wipers (also when I hooked a trailer to it the electrical system seems to be messed up because the trailer lights will not work; went to autozone and tested the trailer and it is fine). The vehicle is starting to act funny again, the engine revs itself to high rpms (this is not the automatic tranny because it happens when it idles as well). The last incident was when I pulled out from a street parking spot and as soon as I put it in drive the vehicle stalled and we lost all power, when I pressed the gas pedal it was as if it was in neutral yet I triple checked and it was in drive. All of the sudden it acted normal and drove about 10 feet then it happened all over again. I also have the rotten egg smell (sulfur?) which is sporadic. Of course the dealer always says they can find nothing wrong, nothing is coming up on the computer. Luckily no injuries have occurred as of yet but I feel it is only a matter of time before I am on the highway and it decides to play these games. Very disappointed in quality of this vehicle, especially since I purchased it because of the reputation.

Filed Feb 19, 2010 · Acceleration, Driver assistance · 15,000 miles · NJ

I purchased a brand new 2003 toyota 4runner in may 2003. In one cold morning of jan. 2005, I was driving it in highway that was still covered with some snow. All of sudden, an engine check light on the dashboard was automatically turned on, followed by vsc lights, indicating that a vehicle skid control function was automatically turned off. At that point, I could not drive the car beyond 50 MPH, no matter how hard or frequently I pushed the accelerator pedal. I pulled over, restarted, and re-entered the highway but had the same results. I managed to drive the car to a dealer for inspection the same day. The dealer could not find a cause and simply reset the computer controller. This seemed to have resolved the problem at that time. However, the engine check and vsc light issues resurfaced about two years later. The difference this time was that there was no acceleration issue. No inspection was made. The dashboard lights were automatically turned off after driving for about a month. In jan. 2010, those lights reappeared and have remained turned on. No impact on acceleration has been observed.

Filed Oct 6, 2009 · Driver assistance, Electrical · 93,555 miles · SC

After replacing an oxygen sensor several times, the dealership finally discovered the root of the problem that is making the oxygen sensor and traction control circuit short out. The air divertor flap inside the HVAC box under the dash had grease applied to the flap hinges in the factory. Directly below the flap is a wiring harness which drops down from the HVAC box and plug into the ecu. Over time the grease has traveled down through the wiring harness to the electrical connection plug into the ecu causing various circuits to short. No damage at present, however various safety circuits such as traction control are being affected. Furthermore, as oil is combustible, an interior fire could result from the oil penetrating the 12 volt electrical connection point on the ecu. This issue/ problem should be considered hazardous and should be a recall to replace the wiring harness and ecu as well as clean the grease out of the HVAC box.

Filed Oct 18, 2005 · Brakes, Electrical · TX

Info copy ltr fwd to toyota regarding front suspension lower ball joint recall, customer dissatisfied w/quality of current toyota vehicles. *ts **reference 10140998*** on 2 occasions, the starter would only click. The vsc, trac, vsc off and ABS lights illuminated and stayed on for a couple of days and finally went off on their own. Two weeks later the lights illuminated again, the consumer took the vehicle to the dealer and upon inspection, they determined a sensor inside the right wheel area had been damaged. The dealer claimed the consumer ran over something. The consumer refused to pay for the repairs. The dealer did inform the consumer if the repairs were not made the anti-lock brake system would not work.