QuestionThe problem is now more clear. The engine actually shuts off momentarily! I believe when it happens on the highway, the engine is running at cranking rpm so the engine starts by itself. It has also happened few times in the parking lot; the engine just shuts off. However, on cranking it also re-starts without any trouble. It may not happen for few days and it may happen twice in an hour!
There was only one time, the engine did not start on cranking after shutting down. I could here the engine cranking but not starting. I disconnected battery cables and re-connected and then again every thing was fine again.
Any ideas where to start with and what to check! I know intermittent problems like this are difficult to diagnose and fix.
Thanks
History:
Question:
QUESTION: 1999 Dodge Grand Caravan 3.3L 4speed 195K
It has happened three times since yesterday. While driving, both Service Engine Soon and Alarm Set lights come on; the van takes a jerk (kind of missing, I believe it loses power for a fraction of a second) and then with in a couple of seconds, every thing is fine again. Out of three times, I was driving at 50 mph and once at 20 mph.
ANSWER: Hi Shafique,
The service engine soon light suggests that an engine fault happened and set a fault code number in the memory of the engine controller. To get the fault code turn the ignition key:" on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window see if the mileage reading is replaced by a 4-digit number preceded by a P. If so let me know the number. If not, then it might be that the ignition switch jiggled out of the 'run' position momentarily or the switch might have a flaky section. But check now for fault codes.
By alarm set light I assume that you mean the vehicle theft security system is activated light. That can happen if a power door lock is activated which sets up the vtss but I can't understand why that should happen while driving unless one of the doors appeared to be 'open' which in effect means "ajar". You might try pushing outward on each of the doors from inseide the vehicle while you are in motion above 15 mph to see if that provokes the door locks to click. If so, then that door is probably not firmly secured in the door frame. So you would move the door striker mounted in the door frame a few millimeters inward so as more tightly secure the door in question in the door frame.
Please read the PS (below) and respond to it.
Thanks,
Roland
---------- FOLLOW-UP ----------
QUESTION: My guess is that, since both lights come on and go off at the same time, it must be a single event that is causing it. Is there any other condition, under which both lights will come on at the same time?
Do the fault codes stay in system even though the warning lights are off now?
The on-off-on-off-on sequence does not work in my van. I must visit a shop to get the codes, so I want to be sure that those are still there.
However, I am inclined to go with your first diagnoses of ignition switch as after these many years, I am now able to take out the key without pressing it a bit! In addition, the Alarm Set will also come on if a key other than the fab key (or I believe equally no key) is used. A jiggling key will indicate both lights. I am thinking of using the key alone (with the weight of key chain and other keys) to see if it makes a difference.
Thanks again!
Answer:
A code is stored for quite a while, but from what you describe it sounds to me like an issue with the ignition switch. So try the idea about the weight on the key. The check engine light, if it truly is reporting a fault will usually remain "on" also, depending upon the severity of the problem.
Roland
ANSWER: Hi Shafique,
I still think it is a section in the ignition switch which is "flakey". The section which is associated with the engine in A21. So my suggestion would be to use a jumper wire (wire with an alligator clip at each end) and once you have started the engine put the jumper between #1 positive temp coefficient fuse-like device and p.t.c. #3, both are located in the row of 10 sockets just below the 4 large multi-wire plugs in the 'junction box' under the dash. That jumper would by-pass the A21 section of the ignition switch. Then see if the engine stops the intermittent die behavior. But be sure to remove the jumper after you shut off the engine.
Please 'rate' my answer.
Thanks,
Roland
---------- FOLLOW-UP ----------
QUESTION: Hi, its me again on a different but possibly related problem.
I believe that may be the immobilizer is activated momentarily, shuts off the engine and then the immobilizer system goes back to normal. This is due to the fact that Alarm Set light turns on momentarily on the dashboard. So far I have cleaned all the grounds, checked any loose or bare wires etc (I still need to check/clean plugs on BCM and PCM as I asked you yesterday).
Now, I am trying to locate the two points on the junction box for the jumper wire as you suggested in your last help to bypass the A21 in the ignition switch. I am not able to located these points 1 and 3! What I see below the four large multi-wire plugs, is a row of 8 (not 10) flat-capacitor like device. I do not see where to hook the alligator clips? Am I on the same page with you?
Thanks
AnswerA better way to by-pass the A21 section of the ignition switch would be to go to the ignition switch and do the jump from red wire on pin 7 of the gray plug which has 10 pin sockets (but only 8 are used) over to the dark blue wire at pin 9 of that same plug. Do that only temporarily after the engine has started and as a test to see if that stops the engine from dying. If it does then that suggests the switch is bad as far as that section of it it concerned. Don't leave the jumper in place continuously.
