How To: Read transmission codes

[bstone]

Once and for all, let's start some How Tos. This one should be how to pull transmission codes. We should do another one for ABS codes.

 

So, here is how to read transmission codes using the "secret handshake" method.

 

1) Warm up the engine

2) Turn the ignition switch OFF

3) Turn the ignition switch ON

4) Start the engine

5) Drive the vehicle at speeds greater than 12 MPH

6) Stop the vehicle

7) Depress the brake pedal and move the gear selector to "1"

8) Turn the ignition switch to OFF

9) Turn the ignition switch to ON

10) Move the gear selector to "2"

11) Move the gear selector to "1"

12) Move the gear selector to "2"

13) Move the gear selector to "3"

14) Move the gear selector to "D"

 

Here is what those codes mean:

 

If the light blinks 2 times a second this means there are no codes.

 

If the light blinks 4 times a second this means there is a power supply or grounding problem.

 

If the light doesn't blink or show up then there is a problem with light's circuit.

 

 

 

Code Item

11 Duty solenoid A

12 Duty solenoid B

13 Shift solenoid 3

14 Shift solenoid 2

15 Shift solenoid 1

21 ATF temp sensor

22 Atmospheric sensor

23 Engine revolution signal

24 Duty solenoid C

25 Engine torque control signal

31 Throttle sensor

32 Vehicle speed sensor 1

33 Vehicle speed sensor 2

Edited November 4, 2010 by bstone

[bstone]

Is it possible to put this as a sticky?

[bstone]

Stick please?

[Legacy777]

You can add it to the sticky compilation thread yourself. Please follow the guidelines in the first post for posting links.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=51554

 

Thanks

[bstone]

I added it there, but I think there should be a few sticking on top of this forum with frequently asked questions- like how to pull CEL codes, ABS codes and TCU codes.

[Legacy777]

All the stickies were compiled into that one sticky. The more stickies you have, the less people tend to look at them.

[Fairtax4me]

How about a listing of what models and years this method applies to?

[Legacy777]

Pretty sure it's 1st gen legacy. Not sure about the applicability on the 2nd gen or later.

[crosjn]

This thread is widely referenced across multiple forums. However, the codes above are for 4EAT phase 1 (pre-approx. 1999) transmissions. For transmissions in later-model Subarus (phase II 4EAT used approx. 1999 to approx. 2004), the codes are :

 

11 Engine speed signal. Detects open or shorted input signal circuit.

27 ATF temperature sensor. Detects open or shorted input signal circuit.

31 Throttle position sensor. Detects open or shorted input signal circuit.

33 Front vehicle speed sensor. Detects open or shorted input signal circuit.

36 Torque converter turbine speed sensor. Detects open or shorted input signal circuit.

38 Torque control signal. Detects open or shorted input signal circuit.

45 Intake manifold pressure signal. Detects open or shorted input signal circuit.

71 Shift solenoid 1. Detects open or shorted output signal circuit.

72 Shift solenoid 2. Detects open or shorted output signal circuit.

73 Low clutch timing solenoid. Detects open or shorted output signal circuit.

74 2-4 brake timing solenoid. Detects open or shorted output signal circuit.

75 Line pressure duty solenoid. Detects open or shorted output signal circuit.

76 2-4 brake duty solenoid. Detects open or shorted output signal circuit.

77 Lock-up duty solenoid. Detects open or shorted output signal circuit.

78 SPORT shift solenoid. Detects open or shorted output signal circuit.

79 Transfer duty solenoid. Detects open or shorted output signal circuit.

86 VDC communication signal. Detects open or shorted input signal circuit.

93 Rear vehicle speed sensor. Detects open or shorted input signal circuit.

 

Thanks to the poster from whom I copied this information, his original post is at:

http://www.subaruoutback.org/forums/99-do-yourself-illustrated-guides/44383-199-2004-how-read-diagnostic-trouble-codes-dtcs.html

 

I'm just trying to help someone who, like me, pulled their codes and thought "oh *&^! codes that shouldn't exist are emitting from my AT!"

 

Jeff

[86subaru]

Mine has 16 flashes. 95 impreza a/t

[upnorthguy]

Had a used 4EAT (with ~80k) installed on my 2001 Forester a month or so ago and it has recently started flashing the A/T oil temp light.  Did the handshake today and I think it is code 78 SPORT shift solenoid - detects open or shorted output signal circuit..

I'm not finding much on this.  Can anyone smarter shed some light on this one for me?  Is this internal to the transmission?  Anything external I can check?

[upnorthguy]

Bumping this one again.  Anyone with thoughts on this?

[upnorthguy]

After on and off problems, including a different code (71) eventually, it was determined that the transmission control module (TCM) was intermittently bad.  A new (used) TCM seems to have finally stopped the transmission codes.