QuestionQUESTION: Car started showing slight "hesitation" when turning the key for about a week. Yesterday, same thing but then a lightly heard "thump" under the hood and now upon turning the key, the normal sound of trying to start is there, but it won't start. Any ideas? Thank you!
ANSWER: Hi Diana,
Try turning the key to bring out the fault codes from the engine controller that will give ua an idea. Turn the key:"run-off-run-off-run and leave in the run position" doing that in 5 seconds or less elapsed time. Then watch the odometer window of the cluster to see the mileage change to show 4-digit numbers preceded by a P. Let me know what you find.
Also, when you turn the key to run position listen for the fuel pump in the rear fuel tank to hum for about 1 second which is normal. If no sound at all listen from outside the car at the rear while a helper turns the key. It shoul just hum for a second or so.
Roland
---------- FOLLOW-UP ----------
QUESTION: The number is 1684 P
The wind is blowing hard today, but don't think there's any sound from the back when in the run position.
AnswerHi Diana,
The 1684 is a code that says sometime in the recent 50-100 key off-on cycles the battery voltage was not connected to the engine control module. That often will be the case if the battery was changed or disconnected. If nothing like that happened, then there could be an electical intermittent "open" that is the issue. Typically though the 1684 happens because the battery is often disconnected when trying to fix something. So if you can't recall anyone dealing with the battery recently, then that code would prompt a check with a volt meter to be sure the controller is indeed getting its voltage source.
There are but two fuses that directly activate the fuel pump, and one of them is also involved with the starter motor, which is working. The other fuse is in the box that is hidden behind a cap on the left end of the dash. So remove that cap and inspect fuse # 13. That fuse too could be involved in activating the starter motor so it could be that you will find it to be OK. But if you find that the wire has broken (blown the fuse) then of course that would be worth replacing or substituting another fuse that is not essential in order to get the fuel pump to work. Ideally you would recall in the past that when you turned the key to the run position that you heard a sound that you no longer hear and that lasted for about a second, but maybe you didn't ever notice it.
If you can get someone to listen in the back seat for a sound coming from under the rear seat, or listen from outside near that area where the tank is located, for such a 1-second humming sound and if it isn't heard and the fuse 13 is good, then that would suggest that the fuel pump is the problem.
There is a fuse box under the hood on the driver side, long and narrow, mounted cross-wise, and if you open the lid look a fuse N to be sure that it is not blown as that one is also involved in powering up the fuel pump but not as directly as fuse 13.
If the pump is working and the fuses are good, then you have to check for spark and for actual fuel pressure to be present (not just the sound of the fuel pump). Other than having run out of fuel, there are no other no start causes that wouldn't cause there to be another fault code in addition to the 1684. Sometimes a component can fail without setting a code and that would have to be based upon measuring with a voltmeter.
So check the fuses, listen for hum, and let me know.
Roland
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PPS: Does the fuel pump relay make a click 'on' sound and then after 1 second does it click 'off' when you turn the key to the run position. It should, and the fuel pump should so likewise. Otherwise, let me know. Did you check fuse 13? Fuse N is the in the front row of smaller fuses, immediately adjacent to the larger fuses. It is 30 Amp size.
If the fuel pump runs, then the only other no start/with no codes item that may be causing this the exhaust gas recirculation valve being stuck ajar. I can tell you where to find that and try one approach to checking that out.
