AT Temp light flashing, code 16

[johnceggleston]

so my AT Temp light is flashing 16 times at start up. i assumed it was the duty c so i installed the fuse even though there were no TB symptoms. the FWD light is on but the fuse did not stop the flashing light.

 

so i read the TCU codes and i get a

''16, torque control cut circuit. open or shorted input signal''.

 

so how do it test this?

is this a bad solenoid or a shorted wire?

 

what is the difference between:

code 16 torque control cut circuit

code 25 torque control signal?

 

suggestions?

or better yet, magic solutions?

 

97 gt wagon w/ ej22 swap. engine has 160k miles, (car slightly less) i did the swap about 30k ago. the trans was replaced before i bought the car, not sure when, but it has always had a harder than normal 1-2 shift as long as i have owned it. my son calls it ''jerky turkey''.

 

thanks,

john

Edited May 31, 2012 by johnceggleston

[johnceggleston]

TCU pin outs from josh.

 

i assume the torque converter is controlled by the duty B solenoid. on page 2 below.

 

 

http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/TCU_I-O_page1.jpg

 

http://www.main.experiencetherave.com/subaru_manual_scans/FSM_Scans/TCU_I-O_page2.jpg

Edited May 31, 2012 by johnceggleston

[nipper]

This sounds like a bad solenoid.

[johnceggleston]

kind of what i thought / was hoping.

 

i was also hoping that the solenoid was accessable without removing the ''valve body'' from the trans. it looks like it might be.

 

this thread suggest i would have a ''code 12'' if it was the solenoid.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=75839&highlight=trans+lock*+torque+converter+solenoid

 

i guess the first step is to check the connections and the resistance in the wires at the TCU.

 

or maybe go read the FSM.

 

i hate this electrical stuff. i have no patience for it.

[johnceggleston]

below from the end wrench .pdf pages 14 - 15.

 

http://endwrench.com/pdf/feb2004pdf/4EAT.pdf

 

what does all this mean ? it sounds like the TCU and the ECU are not talking correctly???

 

Control Unit Networking

Both the Fuel Injection control unit and the

Transmission control unit share processed information

and sensor input by shared signals.

Engine speed signal is sent to the TCM from the

ECM, influencing Torque Converter lock-up.

Torque Control Cut signal is sent to the TCM from

the ECM preventing fuel cut under certain conditions.

Diagnostics are provided by the TCM as code

16, signal diagnostics are not provided

in OBD-II.

 

Torque control signal (unique from the Torque Control

Cut signal) is created in the TCM logic to

communicate to the ECM that torque reduction (fuel cut) is

required to reduce shift shock during a wide-open throttle

upshift. Diagnostics are provided by the TCM as code 25 and

also in OBD –II logic as DTC P1103.

The Mass Airflow signal is sent to the TCM from the

ECM as a back up for influencing the shift points in the

event of a throttle position signal loss. Line pressure is also

affected by the Mass Airflow sensor input, lowering the

line pressure during up shifts, reducing shock.There are no

corresponding onboard diagnostic codes for this signal in

the TCM.

Automatic Transmission Diagnosis Input Signals represent

an electrical check for the circuit that networks the TCM

and ECM, communicating diagnostic information to the

ECM.This signal has no corresponding 4EAT code.

Edited June 1, 2012 by johnceggleston

[johnceggleston]

i would like to thank nipper for the ''magical fix'' he must have given me secretly. my light quit flashing.

 

thinking back before the light first started to flash i seem to remember accelerating hard, wide open and not letting up un till it approached red line. actually about 1500 rpms below red line.

 

and in my reading the code 16 is addressing a ''torque control signal cut'' . i found this to be about a fuel cut signal when shifting at WOT. this fuel cut is to make the shift a little smoother.

 

and mine apparently failed to send the ''cut signal'' during my spirited drive causing a TCU code. and after several drive cycles it reset itself. thank goodness.

 

but it makes now wonder if there is a link in between my harder than normal 1-2 shift and this ''cut signal'' . the code 16 id specifically for shifts at WOT, but what about regular every day shifts. would this ''cut signal failure cause a hard 1-2 shift?

 

is there even a fuel cut programed in for regular every day shifts?

 

any way my car is back to its normal self and i'm glad.

 

thanks for reading.

 

happy motoring

[jarl]

i would like to thank nipper for the ''magical fix'' he must have given me secretly. my light quit flashing.

 

I have to ask: what was the magical fix?

[johnceggleston]

there was none, it was a joke. the event that caused the AT Temp light to flash was a one time occurance. (unless i re-create the situation accelerating at WOT to 50 mph.) but since the light went away on its own, i feel like there was a magical fix.

 

but really , i just got lucky.

[nipper]

SUbarus are known for hard 1-2 shifts as they age.

 

Possibly a bad resistor, which is supposed to throw a code, but they don't always.

 

I dont give away all my secrets ya know

[johnceggleston]

I dont give away all my secrets ya know

if you did , what would you have left to attract good looking women and new / old subarus??? Edited June 4, 2012 by johnceggleston