multi pin connectors

Hi,

The connector pins are from the front, male or female connector. Is that what you mean?

I attached a connector picture of the ECM for your vehicle below. That is with the connector disconnected and you are looking into the connector.

Let me know if you have other questions.

Take care,

Joe

See pic below.

Am I looking into the ECM or the plug?

That is the ECM. In most cases when it is a connector, wiring is shown at the connector. I don't want to say all the time, but most of the time. See pic 1 below.

By chance, is this the vehicle in Florida? Let me know. Sorry to ask, but I just remembered a vehicle similar to this being there. LOL

Let me know.

Joe

Yes, this is the 1995 Mystique from last year in Florida. I'm a snowbird so I'm here for 4 months every year.
The engine is running well now but the transmission is not doing too good. In "D" I have nothing. In 1 and 2 and "R" I get solid engagement. I need a way to electrically test to see if the signals are there.

Hi,

I had a feeling that it was you. LOL Welcome back and boy do I wish I was in Florida. It's 20 degrees here and waiting for a bad snowstorm tomorrow. Ugh!!!

Regardless, when you place it in drive, does the indicator show D? I ask because I'm questioning if the transmission range sensor is bad. Here is how it works.

The transmission range sensor has six separate resistors in series. Each resistor has an output connection corresponding to a transmission position (P, R, N, D, 1, 2).

The PCM applies a 5.0-volt reference signal to the TR pin 30. The signal return circuit, pin 46, supplies a ground path to the sensor. As the transmission is shifted, the TR sensor output wiper arm moves to a corresponding resistor connection (based on gear selection). The six inline resistors provide a separate voltage drop for each transmission position. Based on the voltage signal, the PCM identifies the current transmission shift lever position.

So, I suspect that either the TR has failed, the linkage isn't fully placing the TR in the drive position, or there is an electrical issue. However, if there is an issue within the circuit, I wouldn't think it would be limited to just reverse.

If you look below, I attached the diagnostics for testing. Pic 1 indicates the use of a breakout box, which most people don't own. Since that is the most likely case, you will need to check the return signal resistance at the PCM or the sensor itself.

Pic 2 shows the resistance based on gear selection. Pics 3 and 4 provide the location and directions for removal and replacement. Pic 5 is a pinout of the PCM. I highlighted the pins involved. Pin 30 provides the 5v reference and pin 46 is the signal return pin.

Since the vehicle sits a lot, you may want to confirm there isn't a corrosion issue on the connectors as well.

I hope this helps. Stay warm and let me know if you have other questions.

Take care,

Joe

See pics below.

Back in New Hampshire it was around minus 10. Glad to be in FL.
I checked the TR resistance and in each position the resistance was within the range. How would I check the ECM to see if it is functioning properly? I have the unit out and sitting on top of the engine. I can remove the 60-pin plug easily.

Putt

I thought 20 degrees was bad. No thanks to the neg 10.

I need you to check pin 30 for a 5v reference from the ECM. Also, did you confirm a ground path via pin 46?

Note: I accidentally highlighted the wrong pin above. It should be pin 30 (not 39) that provides power. Also, if you haven't already, disconnect the connector at the ECM and inspect it for damage or corrosion.

As far as testing the ECM, see if there is power and ground for the circuit. If there is, it's good. If there isn't, check wiring between the sensor and ECM for continuity.

Let me know.

Joe

The voltage reading between pin 30 and pin 46 is 4.5v. I checked the resistance of the VSS- 7.8 ohms, TSS-.8 ohms. I'm stumped.

Would I be able to put 5v LED bulbs in series with the control wires that go to the transmission to see if there is anything happening?

Hi,

I don't see why that wouldn't work for testing.

Let me know the results.

Joe

The testing went well, so I decided to go out for a drive. The transmission doesn't seem to know what gear it should be in. It jumps around between gears unless I shift manually but it never goes into OD (light off). What tells it to shift?

Shifting is controlled by the powertrain control module (PCM). The PCM uses information from the speed sensor, throttle position, engine load, speed, and so on.

If the vehicle is shifting erratically, it could be the speedo drive gear, a problem with the fluid itself, or within the valve body. See pic 1 below.

I can't remember, but was line pressure tested? Have you noticed anything related to the speedometer? I likely already know the answer to this, but is the fluid clean and full?

Let me know.

Joe

See pic 2 for a better description of how it works.

I changed the trans fluid last year and added some trans medicine. The car has not been driven in the last 5.5 years so I'm wondering if the solenoid valves have become sticky. Just before the car died in 2016, the trans was fine.

Hi,

You could remove the valve body and inspect it. There are shift solenoids that may be sticking, but that should set a diagnostic trouble code.

Let me know your thoughts. I'll help in any way I can.

Joe

PS: I hope you are enjoying Florida. I have to go plow my driveway now but will be back soon. LOL

Hi Joe, I read something about flushing the transmission with diesel fuel. I guess there are places that do it. What do you think?
We are having bad weather in Florida, low 50s and rain. Still, it beats NH though.

Putt

Hi,

I'm not too sure about that one. If there is a place, will they guarantee it will not damage the system? I know in the old days; people would do that with their engines to clean it out. It worked as far as I know. However, I never heard of it with a transmission. I suspect for a very short period of time; it would lubricate enough to prevent damage. Just don't drive it long like that.

You know, 50 degrees sounds good. LOL Tonight we're down to 2. I love PA. LOL

Take care,

Joe

I decided not to do the diesel fuel flush because I can't see how you would get all the fuel out without flushing with a lot of transmission oil. I'll just change the oil again.

Putt

Hi,

I'm glad to hear that. LOL I was questioning it. Let me know how things turn out for you.

Joe

Hi Joe, I ran into a new problem with the engine. On Monday I drove around for about 45 minutes with an erratic transmission. Then Tuesday I started it and it idled roughly for about 15 minutes and it quit running. Would not restart. The next day I tried my spare ECM and the same thing. The fuel pump was still working normally. Seems like a little heat shuts it down. A lot of black soot comes out of the tail pipe when I rev it.

Couldn't find a reply.

Hi,

It sounds like it's getting too much fuel. Pull a couple of spark plugs and see if they are wet or black. It could be a few different things.

Also, are there any new codes?

Joe

The spark plugs were black and sooty. I decided to check the O2 sensors and both sensor elements are open, so I guessed that I need new ones. The old one had only been in the car 2 years and hardly used.

Hi,

If the sensors are bad, that is the likely cause. Let me know if that takes care of the issue. Also, let me know if there is anything I can do to help.

Take care.

Joe

Hi Joe,

The new O2 sensors will have two white wires for the heater and a gray and a black wire. I'm confused as to which wire is the signal wire connecting to pin 43/44.

Hi,

Take a look at the two pics below and let me know if they help.

Take care,

Joe

I installed the 2 O2 sensors and the car ran much better. No black soot coming out of the exhaust. I'll take it for a road test soon.

Hi,

Thanks for the update. Let me know how the road test turns out and if there is anything I can do to help.

Take care,

Joe

Hi Joe, the road test was so-so but first I'd like to know about the intake manifold runner control. The Alldata-diy shows two wires going to the valve. But the actual valve has 3 wires going to it. One wire comes from pin 32, the other comes from pin 57, the power. The third wire is a mystery. Also, I can't tell which wire goes where in the IMRC connector. Between the two outer wires the resistance is 60.2 ohms.

Putt

Hi,

I dug through the OEM schematics, and they show the same. I did notice there is a splice that the runner wiring is part of.

Take a look at the pic below. Let me know your thoughts.

Joe

See pic below.

That's the same as the ALLDATA-DIY picture I have. I'll follow the wire back toward its other end. This car is a headache.

Hi,

You have more patience than I do. You weren't looking at the connector, were you?

Joe

I have patience because i don't have anything else to do that will interest me.
Yes, I was looking at the IMRC connector.

Putt

I sure hope you're enjoying Florida. It's 8 degrees here tonight. LOL But, I would likely be doing the same thing as you.

I attached the connector below for the IMRC. Although there are two pins at the connector, there are three wires involved. One comes from pin 32 one from pin 57. There is a third that goes to pin 37. It is spliced 57.

Take a look and let me know if that helps.

Joe

See pic below.

It's about 68 here but today I'm resting. I'll look at it tomorrow. Thanks.

Putt

I bet you're getting tired of me and my impossible-to-fix vehicle.
No luck with the IMRC, it seems to have 60 ohms resistance between the two outer wires and putting 12 V to it does nothing.
Meanwhile after the car runs for about 1/2 hour it starts blowing black smoke and will not idle. Fuel pressure regulator?

Hi,

Black smoke indicates a rich fuel mixture. So, it is possible that the pressure regulator is bad.

I hope you are sitting down. I just ran through the procedure for replacing one (which is attached below), and the intake needs to be removed.

As a result, I would check fuel pressure first to confirm that it is the issue. Here is a link that explains in general how it's done:

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

Also, pic 2 shows the pressure specs, and pics 3 and 4 are the directions specific to this vehicle.

Let me know if this helps, and by no means am I tired of hearing from you. I'm a little jealous you are warm, but what can I say. lol 60 here today, rain, tonight, rain to sleet, then to snow. Temperature to drop to 20 degrees. Ugh!

Take care of yourself,

Joe

See pics below.

Fear not, I've had the manifold off before to replace the valve cover gaskets and that came out just fine. Besides once I have the manifold off, I can beat on the IMRC and repair it if possible.
I have to order the regulator so that will take a few days and then the wife is dragging me to Costa Rica to visit her daughter who lives there. She's Chinese and she gets lonely. We'll be there for 2.5 weeks.

Wow, that actually sounds like a great time. I hope you enjoy it. As far as the regulator, let me know if it takes care of the issue. I understand they want to repair a vehicle. I just ran out to look at trucks. Mine is getting old. LOL Forget it. I refuse to pay nearly $50,000.00 for a two-year-old truck with 30,000 miles. No way. I don't understand what has happened over the past couple of years, but it isn't good. Keep the older ones running as long as possible.

Take care of yourself.

Joe