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Web Site Common Hyundai ECU Faults - ECU Testing
Hyundai Common ECU Faults
Non running engine or very poor running
The engine ECU’s fitted to these models are notoriously prone to failure. The problem lies with the type of capacitors used in side the unit that are prone to damage from voltage spikes. Even the voltage spike from an starter motor has been known to blow one of these ECU’s.
Hyundai, all models 1993 - 2004 onwards
Emission Failures
High CO & low lamna reading. common causes of rich running faults are the lamna sensor or the ECU (engine control unit) both of these parts are relatively simple to check, to check the sensor strip back the insulation on the signal wire from the lamna sensor, this wire is usually black. Then hold the bare wire between your finger and thumb then touch your other hand on to the battery positive the internal resistance of your body will give 1volt at your finger tips which is what the sensor would give out when the engine runs rich, if the emissions come down then you have a faulty lamna sensor or wiring but if the emissions remain the same then the ECU is a possible fault. For more information on ECU testing click on ECU
High CO with normal lamna reading. If the oxygen level is below 1% then a high CO with a normal lamna reading can only be one thing - the catalytic converter, when ever you get this reading the catalyst should be condemed. But always make sure you check the oxygen level first, if its high (over 1% at speed) then you’ve got a leaking exhaust or engine runing problems.
Hyundai, all models 1986 - onwards
Hessitation, power loss, missfire. This type of problem can be one of the most time consuming faults to find because the problem often is only slight and the fault only shows up when the car is being driven under load. One common cause of this is a fouled or sticking injector.
Hope this helps