1994 960 sedan with 212K miles. UPDATE: after reading the problem details, see the followup message from me with the trouble codes.

After driving a couple of short trips, in the afternoon I started up my car and the Up arrow on the dash was flashing also 2 of 3 transmission mode lights were alternating flashing but the car runs and shifts perfectly. Transmission mode selector on center console is always set to Economy mode so Economy and Winter were alternating flashing. As a test I switched to Sport Mode and it alternates flashing between Sport and Winter. Switched back to Economy and the alternating flashing lights return to Economy and Winter. Had a similar situation about 5 months ago when suddenly the arrows were flashing when I started it one day. It was not in limp mode then either, it shifted and drove fine. When I finally got around to checking and cleaning the ground points between the battery and chassis and between alternator and chassis with a wire brush, I started it up and the error lights were gone. Checked battery and alternator voltages they were fine. As I say the flashing arrows error was gone and never came back... until today.

Any thoughts or observations? I bought this car 2 years ago and have put a little over 60K miles on it in 2 years. It has had a couple of electrical quirks including this present one and sometimes the doors lock on their own as I'm driving down the road, for no apparent reason. Not like a consistent feature where doors lock when you get up to say 15 MPH, it's not that. After troubleshooting I replaced the door lock relay and the doors locking problem is still the same.

Thanks in advance,
Tom

 

The following day (this morning) I checked for transmission fault codes. I got the following:

213 - Throttle position (TPS) signal too high
233 - Incorrect speedometer signal

This makes sense because I neglected to mention that before the flashing arrows on the transmission mode selector and on the dash, I started having trouble with my speedometer intermittently sticking on zero. I happened to look at the speedo while driving and it was zero, it would intermittently stay on zero like after stopping or sometimes while driving go to zero, and not give a reading then jump back to normal. I haven't driven it enough since this started to provide any additional details but the flashing arrows started right after I started the car, not while driving and not immediately after the speedometer started acting up.

I reset the codes and the flashing arrows went away. Then the problem came back after driving about 20 miles this morning. First the speedometer stopped reading for a bit then flashing arrows started again. I drove it about 120 miles today and always shifts fine, speedo quit working briefly several times. Then eventually the speedo kept working long enough that the flashing arrows went away on their own. Additional info, now it's been 4 additional days of driving the car without the flashing arrow / flashing lights coming back, totaling at least a 300-400 miles altogether without error.

Still looking for advice on the cause off the problem. Thanks.

 

Just to update this thread, I discovered that in my case the flashing lights error is definitely triggered by the fact that my speedometer intermittently stops working. It is sometime shortly (seconds not minutes) after the speedometer quits working that the up arrow on the dash and the transmission mode selector lights start flashing. I also discovered that I can bang on the top of the dashboard with a clenched fist and the speedometer will start working again. And I can confirm that after some period of time passes with the speedometer working normally, the transmission mode lights and the up arrow on the dash will stop flashing on their own. I alluded to this previously but have confirmed it after seeing several cycles of the problem coming back, and eventually the flashing lights error condition going away on its own as long as the speedometer keeps working.

Hope this helps someone else who may encounter this same scenario. The next step for me is to remove the instrument cluster and check and clean the connections on the back side of it. I found a couple of Youtube videos, this one is especially useful.