Question-------------------------
Followup To
Question -
Roland,
Here is the code that I confirmed. 12-14-33-66-13-55
----------------------
Followup To
Question -
I have a 1993 Chrysler Concorde. 3.3L 110K miles
Two questions.
1 – The idle has recently increased to 1200RPM from the normal 800RPM. Just out of nowhere. Just one day, started the car and has an increased idle. Is there an electronic idle sensor that needs replacement?
2 – The front-end clunks from normal road contour (road seam, pavement dip) as you drive straight at low speeds (idle to 30mph) at higher speeds it is not noticeable. It does not affect the steering at all. The steering wheel is turned slightly to the right when riding. The left wheel bearing was replaced about 2 yrs ago. I suspect it is the stabilizer cross-link. Any recommendations on how to confirm?
Answer -
Hi Peter,
The idle speed is controlled by the idle speed motor on the throttle body. The controller reads the rpm from the engine rotational sensors and then sends a signal to the idle speed motor to adjust the throttle to the preset rpm. The sensor could be bad (but doubtful that is the cause) or the idle speed motor might be binding up or have a circuit problem. Fortunately the controller can sense whether there is a problem with most of these components and record a fault code in its memory. You can access these codes with your ignition key. So I would check for stored codes first.
Begin a readout as follows: Take your ignition key and turn the ignition switch "on-off-on-off-on" and leave it "on". Do this switching quickly so that no more than 5 seconds elapses. Then watch the 'check engine' light to begin to flash, pause, flash, pause, etc. Count the number of flashes before each pause and make a note of them in the order that they come. The last two flash groups will be 5 in each. Repeat the readout until you have the numbers accurately (the same result, two times in a row). Then pair the numbers two at a time in the order they came, to form two-digit numbers, for example the last number will be 55 which is the code for "end of readout". The idle speed motor circuit possibility would be a code 25 and the rotational sensors are codes 11 or 54. Let me know if you have any codes other than 12 (battery disconnected recently) or 55 (end of readout).
The idle speed can also rise due to a leak of air into the intake manifold (a "vacuum leak") and the controller adjusts the mixture to compensate, so the engine will idle but at a higher rpm. So it would be good to look for any of the many hoses that are attached to the manifold has become detached or cracked. You can use the underhood diagram as a roadmap to trace all these lines in your search.
On the clunks, it would be good to check the sway bar (stabilizer?) attachments. The next possibility is upper strutmount (top of the strut towers), and lastly the control arm bushings.
Roland
Answer -
P.S. Look at the 3 wires for the MAP too and check that the insulation has not melted between them.
Hi Peter,
That is a formidable number of fault codes. Before I get into the details may I suggest that you re-read the codes and verify each and every one of them. They should come out in numerical order, except that 55 will always be last. Let me know if there is any differences between your current list and what you get this time around. There is no point in chasing a mirage that really isn't present.
12 means the battery was disconnected sometime in the past 50-100 key on-off cycle (not an issue except if you haven't done that then maybe you should check the battery post connectors to be sure they are clean and tight)
13 and 14 are variants of a problem with the Manifold Absolute Pressure sensor system. I would begin by checking that its electrical plug is firmly attached. The sensor is likely to be mounted on the side of the intake manifold, just below the PCV valve, and in line with the '3.3' engraving on the valve cover. Make sure that it is tightly attached to the manifold so that there is not air leak. It should have 3 wires (dark green/red, violet/white, black/light blue). [If you don't find it on the manifold, look for it on the front of the passenger side strut tower, and attached with a vacuum hose to the intake manifold.]
33 says that there is an electrical problem in the circuit that energizes the clutch needed to fire up the air conditioner compressor. Have you tried defrost or A/C lately? Did the A/C compressor fire up? If not then we'll have to do some trouble shooting of that.
66 is one that may be a phantom, though in some settings it is supposed to indicate a problem with communications that are supposed to be handled by body computer or the body computer data bus system. I need you to verify that code also.
So there are a couple of assignments and checks to do. I suspect the MAP sensor system malfunction is what is causing the rapid idle (the controller reverting to a default setting to keep the engine running). So let's see how that might be improved if you found a broken or disconnected vacuum hose to that sensor. It is possible that the sensor has gone bad, but it costs about $70 so you don't want to just run out and get a new one until you have verified the plug and hose.
Roland
Roland,
I did reread the codes four different times with my wife writing down the numbers as I called them.
12- battery disconnect - makes sense, most likely done with the computer body replacement, and will explain further down.
13 & 14- MAP sensor system- I believe I found this unit in between the firewall and the valve cover. The wire colors appear to match according to your description. It is tight, does not appear to be leaking. I did not see an vacuum hose connected. It is only a metal tube that runs into the engine. I am suspecting that this needs replacement.
33- Electrical problem/AC clutch - It appears that this may be a problem, for when I fired up the AC, I did not hear the compressor.
66- Phantom - I wish it was so, but it is not. History - The heating system would come on by itself out of nowhere when driving down the road. My usual mechanic took an educated guess and replaced the body computer in the dash at a cost of 500+. The problem still exists, just not as frequent. My mechanic informed me that it is most likely the data bus system and is more expensive, and I am not prepared to shell out that kind of money again.
So with your expertise, I guess I am expecting some more advise. I really appreciate your thoughtfulness in sharing your knowledge and time.
I am guessing that I need to order a MAP sensor.
AnswerHi Peter,
Yes, unless the fitting of the MAP sensor to the intake manifold is loose (which would constitute a vacuum leak) then the MAP itself is suspect. If you have a voltmeter you could disconnect its plug and check (with the ignition 'on' but the engine noe running) that the voltage between the black/light blue and violet/white is 5V. Then plug it back together, take a couple of very small pins and insert them thru the insulation of the black/light blue and dark green/red wires so that the tips of the pins touch the wires inside the insulation. Then hook up your voltmeter to the pins. With the ignition on it should read 4.5V and then when you start the engine the voltage should drop to 1.0 to 1.5 volts at idle and then if you rev the engine the voltage should momentarily rise while the engine accelerates and then drop back when it is running steadily at a higher rpm. The code says all these voltage changes are not happening, and this will verify the case. If the voltages look o.k. at the MAP then you will need to verify the connection of those three wires to pins 1,4, and 6 of the 60-way connector at the engine controller (dark green/red, black/light blue, and violet/white, respectively).
On the code 66, if you have an automatic temperature control type of heater system then that may be what the code is referring to. The Concorde has 8 different units that are sharing information on the data bus, and the only one that is acting up is the heater control. So you could go to the heater control unit and verify that the pins 3 and 4 of the 8-way plug are clean and making good contact because those are the pins for the data (+) and data(-) wires. Electrically the pins should be connected to pins 26 and 46 of the 60-way connector to the engine controller. If not then there is a break in the wires, somewhere between the two units.
The 33 may mean that the A/C clutch relay is bad or there is a wiring fault to it, or that the AC refrigerant level (pressure) is too low and needs a recharging.
So those are some suggestions as to how to proceed. Let me know if you make some interesting observations and/or progress.
Roland
