Check Engine Light and how to check the codes

[mike-patton]

How do I go about checking the errors codes on my 1996 Yukon. I know where the check point is but don't know how to check with without the adapter and computer. A friend of mine said you could short the bottom left and top right pins together and then count how many times the Check Engine light flashed. Is this correct?

[texasokie]

I dont know if there is an autozone new you, they diagnosed my check engine light for free....

[toppnotchh]

My 94 yukon is running , but after 20 minutes, when it comes to a stop the check gauge light comes on and my yukon starts studderring/hesitating at takeoff. Loss of power and misfiring is also present. Is this my map sensor, Intake air temp. sensor, throttle position sensor, or my O2 sensor. Does anyone know? Thanks Yukons!

[eljones247]

Originally Posted by toppnotchh

My 94 yukon is running , but after 20 minutes, when it comes to a stop the check gauge light comes on and my yukon starts studderring/hesitating at takeoff. Loss of power and misfiring is also present. Is this my map sensor, Intake air temp. sensor, throttle position sensor, or my O2 sensor. Does anyone know? Thanks Yukons!

Also add to your list:

EGR Valve, or torque converter locking up to early.

[SpitAndDirt]

www.troublecodes.net will illustrate how to pull codes out of your computer. You have OBD1 ....OBD2 did not start until late 95. You will be able to use a paperclip and short A and B pins together on your Diagnostic Link Connector located just under your dash above your feet. It has 12 pins. However, you may not have a B pin, in which case you will require a scanner. 94 and 95 are odd years for On-Board Diagnostic techniques. You will have to count the Check Engine Light flashes to get codes. Once you get those codes, then you can troubleshoot from there. Two items though, first make sure your fuel filter has been changed (every year or 12K miles), and second, check the condition of your entire ignition system INCLUDING

[SpitAndDirt]

whoops.....hit the wrong key....... INCLUDING Ignition Module(located under your cap and rotor, can be tested for free at most parts stores), Ignition Coil( also can be tested with an Multi-Meter) and you Ignition Pickup. These items are not monitored directly by the Engine Control Module(ECM), which means if one of these items is faulty it will not store a code. The ignition module is often the most overlooked, underappreciated piece of the ignition system. It needs to dissapate heat through the distributor itself by way of di-electric grease smeared under it. But over time, the unit finally starts to overheat internally, causing no start, hard start, or rough roughing symtoms. Moisture also gets in there to corrode the electrical ground it needs to function properly. I hope this leads you to a solution. -Chris