1998 Mustang GT - Transmission throwing po713 "Trans temp sensor high input"

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thebullfrog

New Member

Mar 17, 2018

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Mar 17, 2018

#1

• Mar 17, 2018

• #1

Hi all! First post because of a mystery issue I can't wrap my head around.
So my 98 GT Auto. started flashing the O/D light the other day. The code is Po713 - "Transmission temperature sensor high input"
Thing is, there is no trans temp sensor in a 98 Mustang GT. Its working fine, fluid is fine, no matter how many times I clear the code, it keeps coming back.
Last year it threw a code for "4x4 Low range switch failure" which obviously also makes zero sense. Never came back after I cleared it.
So, any idea WTF I need to do to fix a sensor that doesn't even exist? I found a thread elsewhere for the same thing in I think a '97 back in 2007. No explanation/fix was ever posted.

 

wmburns

SN Certified Technician

Aug 14, 2009

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Mar 17, 2018

#2

• Mar 17, 2018

• #2

The 1998 GT auto does have a TFT temperature sensor. It's on the pin #2(GY/R and #5(O/BK) wires.

>>From Ford manual
P0713 TFT, Wiring, PCM -40°C (-40°F) indicated TFT sensor circuit open. Voltage drop across TFT sensor exceeds scale set for temperature -40°C (-40°F) Firm shift feel. Refer to Pinpoint Test B .

 

T

thebullfrog

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Mar 17, 2018

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Mar 17, 2018

#3

• Mar 17, 2018

• #3

Well what the crap? I can't find a replacement for it anywhere.

 

wmburns

SN Certified Technician

Aug 14, 2009

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Mar 18, 2018

#4

• Mar 18, 2018

• #4

Consider the TFT sensor may be part of the circuit board inside the transmission.

Or the problem is in the wiring harness or even the connector.

Do you have a Ford service manual and wiring diagrams? If interested in getting a copy for yourself I maybe able to help. PM if interested.

 

T

thebullfrog

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Mar 17, 2018

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Mar 18, 2018

#5

• Mar 18, 2018

• #5

I don't, but I really don't understand how it is I can't find any reference to the thing existing or its location anywhere. With the millions of cars on the road with this trans, I'm the first person to have this CEL? I feel like it shouldn't be this hard to look up what I need to replace (assuming, obviously it isn't a wiring issue in the harness)

 

T

thebullfrog

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Mar 17, 2018

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Mar 18, 2018

#6

• Mar 18, 2018

• #6

OK, post on a Crown Vic forum says 98+ it's integrated into the harness (somehow? no explanation) but of course that's on a Crown Vic, who knows what kinds of minor things Ford tweaked between the cars. I've never had such a hard time finding such basic info for any car before *sigh*, I might have to make a couple phone calls to get hold of an old family friend who was a Ford tech for decades.

 

Neuron

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Nov 6, 2016

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Mar 18, 2018

#7

• Mar 18, 2018

• #7

"Do you have a Ford service manual and wiring diagrams? If interested in getting a copy for yourself I maybe able to help. PM if interested."

Best thing you can do, now and for the future.