QuestionHi Hope you can help This is a 1991 Dodge Dynasty 3.3 engine auto tranny. It starts then dies. But never idles. We do not have a manual on the car. Here are the codes it displayed. 12,42,24,17,35,55. We then disconnected the battery and now it displays no codes.the car has only 58,000.00 miles on it. We are stumped.
Debra
AnswerHi Debra,
Disconnecting the battery erases the codes, and they may not reset until the conditions that qualify for coding are experienced by the engine, so that is not unusual. If the codes self-correct or are corrected, they are usually self-erased after 50 key on-off cycles. So I suspect that all the codes are valid and need to be addressed.
Several are relavant to a no idle situation and I have one more to suggest as well. The 24 code says that the throttle position sensor voltage is out of normal range and usually means the sensor or its wiring are damaged. Such a situation might prevent idling and will certainly prevent proper running of the engine on the road. The 42 code says that the Autoshutdown relay (ASD) has a problem in its circuit. That relay is necessary to function in the activated state to supply electrical power to the spark circuit and the fuel pump and so that too would be a cause of a failure to idle. The 17 code says that the coolant temperature sensor is reporting that the engine stays cold too long which may be due to the thermostat being stuck open or the sensor itself may be inaccurate. And the 35 says there is an electrical problem with the electrical circuit that operates the radiator fan relay so that the fan(s) might not come on when the engine gets warm and needs that supplementary cooling. The 17 code and the 35 code might be a problem once the engine warms up, but would not usually keep the engine from idling when cold. The 12 means that the battery had been disconnected sometime in the recent past, and the 55 means end of code readout. I might mention that another reason for non-idle is a sticky exhaust gas recirculation valve that might be ajar when it should be closed (at idle) which will also cause a no idle.
I don't know how knowledgeable you or another family member are/is about checking out these several circuit and mechanical issues. I have the circuit diagrams and a '91 shop manual that describes where the components are and how to service/ replace them. It doesn't have detailed step by step procedures to diagnose exactly whether it is the component or its wiring that needs attention. It would be helpful too to have an volt-ohmmeter for testing. I can make xerox copies of the diagrams and text at 4 cents per side and postal mail them to you.
I can't tell you whether any one of these several issues alone, if dealt with, will make the engine idle. But I would start with the throttle position sensor and the ASD relay and check out the egr valve for binding up. Then if that doesn't correct the problem work on the cooling issues (thermostat, sensor, fan control).
I await your disposition as to how to proceed. It is a fairly complex engine layout that one has to work with so it will require a commitment by an amateur to learn the basics of repairing it. None of these items in and of itself is a costly part or a major repair, but the learning curve is a bit of a challenge if you are not familiar with current auto technology.
Roland
