QuestionQUESTION: After cleaning out the EGR Valve and tubing, we have three new codes and the check engine light is on. 1st code is P1684, 2nd code is P0123 and the 3rd code is P0113. Where do we go from here. Thanks, Debbie
ANSWER: Hi Debbie,
The 0123 says the signal voltage from the throttle position sensor is higher than it is expected to be for at least 0.7 seconds. This could be a switching transient pulse that is not relevant, or it could mean that the sensor has failed, or that one of the wires (signal or ground) between the sensor and the pcm is open due to a problem with the wiring. The signal voltageis measured at pin 36 of the pcm, and varied from about 4.5 to 0v. as you move the throttle. Gently shake the harness as you test it. The sensor is on the throttle body at the level of the butterfly valve and has three wires, the signal wire being orange/dark blue on the middle pin. But I would think the second code will be more related to your hard starting.
The 0113 says the signal voltage on the intake air temp sensor is higher than expected. Again, this could be a sensor failure, or a signal or ground wire open. Now this one may be more relevant to your hard-starting and smell of fuel because such an erroneously high voltage would cause excess fuel and possibly be flooding the engine with a too rich mixture. The sensor is really two sensors is one, the manifold air temp sensor and manifold air pressure sensor. There are 4 wires on the sensor: the air temp signal is black/red on pin B of the plug and the common signal ground wire is black/light blue on pin A. Those wires are connected at the pcm to pins 37 and 43 if you want to check continuity, gently shaking the harness. The sensor itself should show about 7-14k ohms when cold, and 700-1k ohms when at full operating temperature, measured between pins A and B with the plug removed. The sensor is located on the left side of the intake manifold plenum, just adjacent to the oil dipstick.
The 1684 just says that the battery was disconnected recently, which probably you have done in servicing the engine.
So start with the intake air temp sensor checkout. I wonder why the first two codes just appeared if all you did was involved with the egr. By the way, was the egr a mess?
Roland
PS Thanks for the ratings.
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QUESTION: the codes were wrong .still same hard to start and still smell gas after it starts it shows no codes . egr a mess
ANSWER: Hi Debbie,
I am not sure what you meant by 'the codes were wrong'. Can you explain why or ?
Maybe the egr valve is still stuck ajar. When is was cleaned did you verify that the valve stem moved freely, against spring-action that tries to close it, and did it positively close the valve?
All I can suggest regarding a hard start with no code is that either the egr valve is stuck ajar or that one of the sensors is off-value but not so badly as to cause a code, your intake air filter is clogged, or finally that your spark plugs may be worn out (how many miles since last changed).
For example my car, when it would not start and showed no codes, actually had a MAP sensor that was reading inaccurately but the only way that was found was via a professional-level diagnotic readout box (more elaborate than a code reader).
So other than removing the egr and checking the 'action' of the valve stem, or changing the plugs if they have gone close to 100,000 miles, or change the air filter if it has been in place for more than 30,000 miles, or check the pcv valve for function, all I can suggest is that you keep watching for any new codes OR go to a dealer and have the driveability expert look over the data stored/while the engine is running that is shown by the powertrain control module by using his diagnostic readout box to see if he spots something that is amiss. At a distance I can only go on the basis of fault codes. The plugs/air cleaner/pcv are part of routine maintenance and might be causes for your problem.
Roland
PS Please 'rate' my answer. Thanks
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QUESTION: How do you test erg? There was a lot of suet that came out of the erg and the pipe. Cleaned it out atleast 20 times. We blew on the erg valve and nothing came out,(this was when it was off the car). When I got the codes, the car was on, while everything was diconnected. After connecting everything back up, there was no code.
There was one time, when the check engine light was on, at that time we pulled the top of the engine off and under it we found that there was caps were missing. There was a vacuum leak, after fixing the leak, the car started fine for a couple of days, until the check engine light was turned off. Since then, the car is having trouble starting. Where do we go from here.
Thanks, Debbie
AnswerHi Debbie,
On the egr valve, find the valve stem if it is available externally without removing it and try to see if it moves well. I don't have the same valve here to inspect so I can't be sure whether that is possible. If it is not accessible then all you can do is take it off again and try to move the end of the valve at the valve seat, internally, and see if it is moving freely.
Other than that, everything else I can suggest is covered in my previous answer. Consider those suggestions, please. You may just have to ride it out until a code appears or go to a good shop.
Roland
