P0705 & DME

[MX7]

Okay, this is why this car is my LEAST favorite of the 7 cars I own…

This morning I start the car. While still in park, I get the gear light indicating (from experience) that I have the shifter position switch error again. I immediately turn the car off - move the shifter back and forth a dozen times - and restart. The gear light is gone - but I immediately get the trifecta of the low tire P, Brake and triangle/arrow (DSC) light. This is all with the car still in park. After cursing a bit I take the car for a spin.

I stop and have lunch.

Get back in the car, start it, and the 3 lights are again illuminated. I drive home.

I turn the car off - and then restart it - no lights on the dash. I take it for another spin (short - 10 minutes) with no lights. ??? WT?

Last year when I replaced the yaw sensor the carpet was wet. Checked it now - it’s good and dry.

Is the yaw sensor INTERMITTENTLY failing? What else could cause this?

A minor (likely not contributing) note - a few years back I replaced the run flats with regular tires to improve the ride (which it did). The tires are also a little over-inflated (35-36 lbs all around).

I’d like some advice on how to check that the alternator is working properly - and any other suggestions anyone might have. The reason the car is 18 years old and only has 36,000 miles is because my wife “doesn’t trust it” as it’s always throwing dash lights that freak her out!

Trying to sort this once and for all, but my patience is running thin!

[MX7]

How does this make sense?

Started the car this morning. I have the shift selector (TCM) error AND NOW the check engine light. Turned the car off and back on twice - no change, but I also have a bulb warning. As I back out of the driveway the bulb warning goes out.

I literally go around the block and notice that there is no “D” indicator on the dash. The car also seems stuck in 2nd gear. Back in the driveway I leave the car running, pop in my reader and clear all the codes.

I then proceed to drive the car for about 90 minutes - it runs fine. No dash lights. “D” indicator on the dash while in drive. Transmission shifts normal.

The car is now running in the driveway. I’m going to take it for another spin to ensure all the monitors are set then to my mechanic to get an inspection sticker so I can continue to troubleshoot and drive the car legally.

Does anyone have any idea what’s going on?

[MX7]

Drove the car about 120 miles today - stop and go, highway. Didn’t turn the engine off for 5-1/2 hrs. No codes or dash lights appeared.

Tried to get the car inspected (after clearing the codes first thing this morning). After all that driving it won’t pass since two monitors are showing incomplete (EVAP and Sec Air System?). I’ll create another post for these.

I checked voltage at the battery with the car running. At idle, and at 2500-3000 rpm I’m getting 14.1-14.2v. I was expecting/looking for 14.7v. Does this suggest an alternator issue? Voltage regulator? Other ideas?

[MX7]

I see the evap needs a cold start. Wonderful. I’ll start jr the next 2 days and drive it. Based on recent performance I’m likely to get an error code (or 3) while doing that, and have to start all over!

[MX7]

Last post of this frustrating day: after running the car all day, turned it off and let it sit in the driveway for an hour. Upon restart - as expected - I immediately get the DSC/Brake/Low Tire Pressure dash lights. I drive the caress than 1/2 mile, turn it off and run into the store for 5 minutes. On return no lights at startup. Drive another 1/2 mile - off for 5 minutes - restart. Still no lights. 1.2 mile back home and I check for codes with my scanner - no codes.

I’m sure when I start it tomorrow morning I’ll have the 3 lights again!

[MX7]

Update: yesterday I had plans to watch football all day. Went out early evening and drove the car for about an hour. No dash lights whatsoever. The sec air monitor set, but the evap did not. I’ve read that it should pass inspection even with the evap monitor Inc - but I’d like to get it set before taking it in just in case. Read the forum and found suggestions about letting it idle from the cold start etc to reset it.

Drove the car late night again with no dash lights.

This morning started it up and immediately had the TCM (trans control module) error. No “D” indicator on the dash, and the engine revving high relative to the speed I was driving. Tried the 5 minute idle - 10 minute drive - 5 minute idle but the evap did not reset. After 45 mins or so turned the engine off. Waited 30 seconds, restated and the dash light went out and the transmission shifted as normal. Stopped to run an errand - when I restarted the car the dash was again clear.

The gear/sprocket TCM error has plagued me now for about 2 years. My wife won’t drive the car with it occurring (it’s her car). I’m going to have to bite the bullet and replace the shift selector switch. I’ve looked online and see videos to rebuild the switch, but none to remove it. Does anyone know if a DIY tutorial to do this job? My mechanic told me the transmission needs to be dropped which is beyond what I’m willing to do. Comments/advice appreciated.

[MX7]

It’s been 3 days now where upon initial startup I get the TCM/gear sprocket dash light and the car is stuck in 3rd gear - but after driving it for 5 mins and restarting it the engine the light is gone for the remainder of the day and the transmission shifts normal.

I’m planning to order the switch. I’d like to try to install it myself if someone can help with a tutorial.

[enuff_zed]

It’s been 3 days now where upon initial startup I get the TCM/gear sprocket dash light and the car is stuck in 3rd gear - but after driving it for 5 mins and restarting it the engine the light is gone for the remainder of the day and the transmission shifts normal.

I’m planning to order the switch. I’d like to try to install it myself if someone can help with a tutorial.

Have you tried starting in Neutral instead of Park. That may work and save the 5 minutes of pain.

[MX7]

I’ve read that some have had good luck with that, but it’s my wife’s car and she’s just not having that. I appreciate the suggestion though.

[enuff_zed]

I’ve read that some have had good luck with that, but it’s my wife’s car and she’s just not having that. I appreciate the suggestion though.

Why not?

[MX7]

Well…. Because she’s going to say she shouldn’t have to do that, and the fact that she does means there’s something wrong with it. She doesn’t want to drive a car that has an issue - because in her mind that leads to other issues. If I convince her to drive it like that and she gets a flat tire a year from now, she’ll say “there’s always something wrong with this car!” It’s just not worth it to me. She expects her car to work as intended, which isn’t really an unreasonable ask.

[enuff_zed]

Well…. Because she’s going to say she shouldn’t have to do that, and the fact that she does means there’s something wrong with it. She doesn’t want to drive a car that has an issue - because in her mind that leads to other issues. If I convince her to drive it like that and she gets a flat tire a year from now, she’ll say “there’s always something wrong with this car!” It’s just not worth it to me. She expects her car to work as intended, which isn’t really an unreasonable ask.

I expect my wife to work as intended. That however IS an unreasonable ask it seems.

[MX7]

After disappearing for a couple of weeks my DME errors is back.

This morning I have the ever present P0705 transmission light and the 299A DME:CAN fault EGS. For the first time I also got the “service engine soon” yellow light so I broke out my code reader and also found several other codes. These are:
- 30 KBus or control unit for instrument cluster basis (Gateway)
- OE Power window open circuit jam protection strip of scaling/error EKS electronic passenger door
- OD (same as OE but for driver side door)
- 38: wiper pump or container empty (I checked and the pump works and the container is empty)

First time I’ve seen these other errors. Could they be linked to the DME error or are they totally separate? Any ideas what triggers these other errors?

[enuff_zed]

Anti jam is in the GM5 I believe. However, you can get it if you read the codes with the doors open.
Try a reset on the windows to see if those clear.
As I think was previously mentioned, a lot of the modules (including that GM5) are linked through the K-Bus (CAN). If one module has a problem it can then cause other modules to show errors too.

[MX7]

I had the switch replaced today by my local mechanic. I purchased one on eBay (from China I believe - $108 delivered) and my mechanic had it installed in less than 2 hrs and charged me $95. The gear switch, DME and CEL lights/codes all disappeared with the switch replacement!

I drove the car today to do some Christmas shopping. I was out about 5 hours, drove the car about 35 miles and stopped in about 5 different places. It’s only 1 day but so far so good!

The other issues (roof motor) will probably have to wait until Spring, but for now I couldn’t be happier!

Many thanks to all who weighed in on my thread and offered suggestions and advice - especially enuf_zed. I would not have gotten this far without everyone’s help!