QuestionQUESTION: I have a 2002 Hyndia Elantra GLS, I have replaced the TP Sensor, MAP Sensor, Boesch Platinum Plugs, new wires, CPS, idle control valve, PCV, ECM, battery most parts have been replaced at a dealer. The car has been at a Hyundia dealer 3x's for the problem with the check engine light comming on for a split second and then going off. The car then jerks and seems to loses all power for that split second. The car has also completly died while comming to a stop at a stoplight This can't be that difficult to diagnois correctly or can it? do I have unrealistic expectations?-Please help me out because this is getting very frustrating-HELP??? I took it to a hyundia dealer service center due to the nature of the problem in order to get it fixed correctly. Not to return it 3 seperate times.
ANSWER: Hi, David. It sounds to me like this may be an intermittent issue causing the engine control module (ECM) to power down and then back up. In such a case, diagnostic trouble codes may not be stored, because as far as the ECM knows, the car was turned off and back on. The source of such an issue may be difficult to find for several reasons:
1. It could be caused by a large number of potential failures.
2. Testing and diagnosis is unlikely to pinpoint the issue because all test will return proper results while the specific issue is not occurring.
3. Problems electrical in nature can often not be identified by visual inspection.
Presuming you indeed have no trouble codes in the ECM, I think I'd start my guesswork at the engine control relay. This would cause all the symptoms you've listed and is an inexpensive component to replace just to see what happens.
I'd also check to be sure the battery is securely and properly installed and that there is no place where the positive battery terminal or cable could touch the engine, transmission, or body of the car.
How frequently does the issue occur? If it happens once a day or so, I might also suggest requesting the shop have a technician drive it home and back. This way, the technician will have a way of knowing whether the car is fixed prior to releasing it back to you.
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QUESTION: The car was in previously for 6+ days, then it was returned to me after the ECM and the CPS was replaced. It ran fine for about 1 week(about 100+ miles) and then the problem started again with the check engine light flashing on briefly for about 4-5 x's and then stalling when I came to a stop at a stop light. Would this still sound that it was the ECM relay? I will send this info. to the dealer that is repairing the car. Any help is much appreciated.
ANSWER: It's possible that it could be the relay, but it's also possible that it could be any number of electrical issues. While you're welcome to share what I've said here with the dealer, I doubt this will accomplish anything of significance. All Hyundai dealers have access to Hyundai technical assistance, which has access to a large database of problems nationwide. So my questions regarding the repairs would be these:
-- Is the vehicle in the hands of the most capable diagnostic technician at the dealership? I don't know why the plugs and wires were replaced-- perhaps they were old/worn-- but it's nearly impossible that they'd cause this condition. Similarly, it'd be very surprising if the PCV valve were causing this problem. The other items, on the other hand, are plausible causes. You'll want to make sure this vehicle is with the best technician for the job. Of course, you'll know nothing more than what the dealership personnel tell you in this regard.
-- Has Hyundai technical assistance been contacted? Hopefully, by now, they have been. They may be able to offer assistance as to what may be causing the issue if they have in their database similar cases.
In addition, I have the following questions to help me better understand what is occurring:
1. When you say the check engine lamp flashes, do you mean that it comes on and quickly goes back out, or is there a repeated flashing (1/2 second on, 1/2 second off, 1/2 second on, 1/2 second off, and so on)?
2. Did the dealer attempt to read trouble codes from the engine control and transmission control modules? If so, what trouble codes were stored, if any?
3. How frequently did the problem occur prior to servicing?
4. Is the problem again occurring with that frequency after the 100 miles?
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QUESTION: Hi-vehicle is in best hand of a diagnostic Tech. at the dealership. Hyundai technical assistance is being contacted and used per. being verbally told by the dealership service manager. check engine light flashes on 1/2 sec. on and off immediately in rapid succession then does may times repeat itself, then as I stated previously the car seemed to lose power and completely died when I came to a stop at a stoplight. The dealer told me that no codes were present from the ECM, however I don't know if they tried at the TCM. The problem occurred often before servicing, and seemed to get worse while waiting for Apt. to get car in. After got car back after 6 days in dealership ECM replaced as well as the CPS this did not occur nearly as much. As a matter of fact the car ran fine without incident for about a week after I got it back from the dealership Hyundai service center. The Tech. says that he found numerous relays for a remote starter that was an after market add-on, not a Hyundai original. He thinks that may be the issue, is this possible?
AnswerIf the system in the car has the capability of inhibiting the engine from running, then yes, this could be the problem. The installation or components could be faulty. I find it odd that it wasn't recommended to disconnect this system for the purpose of determining whether the problem was with the vehicle or with the remote start system.
