rstandke

I have been searching for how to do this for some time and have finally found a solution. However, the catch is it requires the "not too difficult" installation of a push button switch connected across the transmission temperature sensor wires.

While you push the button (for about one second) the PCM thinks your transmission temperature is over 300 F and the DIC displays "HIGH TRANS. TEMP." Then push Reset to clear that warning (before it goes away on its own in a few seconds), and you have "TRANS FLUID 123 F," for example. This parameter gets inserted in the Gages sequence between Coolant Temp and Battery Voltage. Once on, the transmission temperature display will remain on regardless of the temperature. In fact, it will still be there when you turn the car off and back on. But, if you push Gages to look at other parameters it won't be in the sequence any more. To get it back just push your new button again.

You can install the button anywhere you want. Some minor surgery is required. I found it easy and neat looking to install it in the recess behind the Active Handling button (which requires drilling a hole). From there it was easy to route the wire through the parking brake cable boot to get it under the car near the transmission. From there route it to the connector that attaches to the transmission fill plug (which is the temperature sensor) and splice into the wires.

Normally you would get the "HIGH TRANS. TEMP." warning when the temperature exceeds 270 F, and if you clear that warning with the Reset button the transmission temperature will be displayed. Because the resistance of the sensor becomes lower with increasing temperature, a momentary short circuit makes the PCM think your transmission is really hot and puts it in the over temp display mode.

joopblog

I solved my transmission over-temp problem on the racetrack by using header wrap on the exhaust pipes that run alongside the tranny. Other people have added the GM radiator/pump kit that is about $1200.

crazyv6

Great work!

rstandke

Here's a follow up regarding joopblog's advice to use header wrap. Under similar conditions on the race track, my transmission temperature dropped by 20 degrees F. I covered the exhaust pipes starting at the front of the transmission and ending at the top of the "hump" by the differential.

skyavonee

I'll have to keep that header wrap idea in mind

Bills Z06

The wiring solution is a good idea - I may give it a try.

RDnomorecobra

just check on it occassionally. if you have any kind of oil leak that soaks into that stuff it becomes a fire hazard.

NatB

Good Safety Observation !

SteveDoten

good info

the exh. wrap is also a good proactive approach, but the OP'er getting the trans temp is interesting

crimsonwake

Definitely interested in this mod, might I ask if you have nay pics of the switch or how you wired it?

TEXHAWK0

It doesn't seem like a good idea to intentionally short the sensor wires. I would be afraid it would end up messing up the control module...

What about wiring in a control circuit that just changes the resistance when you push the button?

The Highlander

Would love to see this too. I tried but it didn't display anything... I tried reading it with efilive, but it wouldn't read anyways..... pegged at minimum.

Must_Have_Z

I just used a Scan Gauge II and programmed in the custom code for the car. Works like a charm.

ZeeOSix

Are you talking about a good OBD II scanner? Where is this "custom code" info? Need more details.

crimsonwake

I think he's referring to this:


Looks pretty cool.

The Highlander

I managed to finish the mod, the reading will peg at 275F, but it will NOT say trans over temp nor will it display the temp on the DIC.

Could it be because i have a road runner?

guzerone

I'm using an old Android tablet (Samsung Galaxy Tab 2) and a Bluetooth OBD adapter.
Running Torque on the tablet, I can read out the trans temp and many other parameters. Found some interesting data, I didn't expect hat it flows 2400+ CFM through the MAF at WOT or that it runs over 40 degrees of timing..
I also use this setup as track data logger running aLapRecorder (GoPro for video).
Sadly, engine oil pressure and oil temp are not exposed via OBD on my 01 Z06.

The Highlander

They do, they just do oil pressure voltage and you need to convert.