[Donnell]

So, check this out ...

For the last 5 years The D light has been flashing. It would flash from intervals of one week - randomly - to now every minute ... and then stops. ... Annnnd then back to flashing. Needles to say the check engine is on currently.

But get this ..... The check engine light was on constantly for the last two years but I filled up with Shell V Power instead of any other gas once last year which broke the Check engine light curse. With this said the check engine light is on constantly but may cut out for the next 15 minutes even when parked and then restarted.

I've changed the Transmission pressure switch three times to see if the switches were faulty; oem, aftermarket, junkyard oem with harnes; nothing.

which leaves a few things assuming that the problems are not related; the transmission pressure switch for the flashing D or a faulty ecu for the p1705 ... aftermarket starter installed 2 years before the problem ignited.

transmission fluid upkept and filter changed ... Go!

( after 5 years im tired of looking at it and about to submit to a trans specialist)

 

[Donnell]

in fact i'm nibbling at it

 

[CalgaryTSX]

Without getting into analyzing all the DTC's your getting (you only mention one), a good used 2004/05 auto trans ECU is readily available and cheap.

I would be trying that option before yanking the auto trans.

 

[Donnell]

First ... I plan to replace this as well and to your point yes, it's cheap and a good starting point. But also to your point it's only one BTC ... But WITH the flashing D ... Why wouldn't the logical play be the sensors;

no hard shifts; maybe a random pop every blue moon after being parked; when placed into drive on a hot day there is a very very small jerk (so small that if you are on the go and not looking for it you wouldn't even know) and that's it.

Talk to me; what are you thinking ... 🤔

 

[CalgaryTSX]

I'm not familiar with this generation of TSX automatic transmissions.

Are you getting any other DTC's in addition to P1705?

I just quickly did a google search on Acura and P1705: "DTC P1705: Short in Transmission Range Switch Circuit"
This sounds like the gear lever selector switch/sensor assembly.
This does not sound like the transmission pressure sensors.
This could explain why the trans has been and is driving fine but is logging DTC's.

So my recommendations are:

1. Pull your ECU (simple to do), check it for corrosion. Research good used ECU's.
2. More research on P1705. Is there a transmission selector switch/sensor assembly for a TSX auto trans?
3. Perhaps an Acura dealer or garage specializing in Acura auto trans can connect a more sophisticated scanner to your car to get more detail on the transmission errors?
Contact these shops to ask them.

How many miles on your TSX? The fact the trans has been and is driving fine is an excellent sign.
The 1st Gen TSX auto trans is lame from a performance point of view but is extremely reliable.

 

[Donnell]

Is there a transmission selector switch/sensor assembly for a TSX auto trans? No idea. it will be uncharted territory; I'm going in! I'll be back in a month!
3. Perhaps an Acura dealer or garage specializing in Acura auto trans can connect a more sophisticated scanner to your car to get more detail on the transmission errors? I have and will continue - even my local Honda certified auto shop doesn't want to dive in on it. i may have to take it home (the dealer) if i cant figure it.

 

[Reorge]

P1705 is not listed in the TSX service manual. As mentioned above P0705 is and is usually associated with a blinking "D" transmission indicator in instrument cluster. Are you certain of the DTC code?

 

[Donnell]

Yea you are right. It's 0705. My error. And yes it's transmission range/control; all of that

 

[CG1120]

There should be a range switch on the outside of the transmission. Also known as neutral safety switch.
This one could take some diagnostics, however. I had an Odyssey with a similar code. An electrical issue AT THE BACK of the van was causing a P code in the ECU. Not saying this is the same issue, but it may require testing beyond swapping parts

 

[Donnell]

You are accurate. I've tried three; and oem, an aftermarket and a junkyard to no avail. I think think the flashing D and code are indipendant from each other ... We shall see

 

[CG1120]

You said pressure switches above. Perhaps I missed you replacing the range switch.

 

[Donnell]

Nope replaced that too. However I tried an accord range sensor on my tsx and the light went out. Imagine that right ?!

 

[CG1120]

So problem solved?

 

[Donnell]

Nope. Give me a month or two.

 

[Donnell]

small steps!

parts reordered.

but for those of you stuck at that battery tray? peep!

 

[Donnell]

The "Flashing D" is most associated with the transmission pressure switch. in this case it was not!

going to the ECU next.

 

[Donnell]

Not the ECU ... I'm going to have the transmission codes read in two weeks.

 

[mojo]

My daughter has a 2004 TSX as well, 230K miles. Blinking D light occurred 7 months ago along with P0705 code. Had the Transmission Range Sensor switch replaced and the blinking D went away until last month, when it returned, along with the Check Engine Light.

Donnell - have you made any progress sorting this out since your post in November?

Thanks for your determined efforts to document and track down this problem. Much appreciated!

 

[Donnell]

No I have not. the local transmission shop told me that it would take 4 days for them to diagnose the transmission when I called them and a 450 fee ... it deterred me again. So I bought a transmission coder reader as it yielded me codes that lead me right back to what I already know/knew or what the check engine is showing; transmission range sensor.

but check this out!

I continued to read through forums and posts but have been deterred from the project with other projects on the car via my YouTube channel BUT!!! one of the codes read something concerning low voltage to the transmission range sensor! I dug some more but after a lot of posts, ... ... apparently, anything aftermarket with the starter can mess with/pull voltage from that sensor apparently! I plan to read the codes again; I bought a Foxwell 640 OBDii or something of the sort and made sure it read transmission codes and that I paid over 140 for it from a suitable vendor. but low and behold I have an aftermarket starter and may be pulling it off, all to get this code out of my face!

And understand that faultily aftermarket and genuine oem parts can fail; I went through two knock sensors in a month so it can happen.

keep me posted on your end!

 

[mojo]

Thanks for the quick update! Sorry to hear you haven't had any luck.

No aftermarket starter on my side.

My pressure sensor and ECU are also both original, so even though replacing them hasn't solved the problem with your car, sounds like research says they often are the cause of the flashing D and are worth replacing?