Automatic transmissions don’t like to be too hot or too cold. If they get overheated, they can be seriously damaged. SureTrack community member Tech12345 had a Subaru Outback in the shop where the automatic transmission temperature light was flashing. They found and repaired some damage to the transmission but the light continues to flash. They posed the question to the community, and with the help of fellow community member ericsautomotive and others, they were able to resolve the issue quickly.
The following Community Fix summarizes the interaction between members of the community that led to the solution.
Vehicle
2001 Subaru Outback 2.5L
Title
Automatic transmission temperature light flashing, repaired wiring.
Complaint
Customer complains that the automatic transmission temperature light is flashing.
Diagnostic Steps Performed/Parts Replaced
Road test vehicle. Automatic transmission temperature light is flashing constantly and there is delayed shifting. Soft code P0778 (2-4 brake pressure solenoid valve circuit) which transfers to a transmission code 76 (Brake duty solenoid). Ran through flow chart and dropped transmission pan, which was severely dented or had a jack used against it. Peened out the pan, and saw that the 2-4 duty solenoid was broken. Replaced the solenoid, and the temperature sensor, replaced the transmission fluid. Cleared codes, both PCM and TCM, and immediately on restart the A/T temp lamp flashes and does not stop. And then a soft code sets in PCM and TCM for same code. Is there a specific relearn procedure for the A/T lamp issue or am I overlooking something?
Best Answer from Community Member ericsautomotive
The brake duty solenoid is in the rear housing. Did you trace all the wires in the pan area? Maybe the one to the brake solenoid got pinched?
Cause
Although resistance tests showed good. I found that when the circuit was powered up that I had a significant voltage drop. Found damaged wiring.
Correction
Repaired wring to circuit and retested, all is good.