360 F1 pump has gone south?

I have a 360 that shifts into all gears fine when cold, and the pump takes 10.5 seconds to prime the system at start up when cold. But when it has fully warmed up ... the F1 light flashes on and it cannot shift into 3rd gear or higher.

I am thinking the F1 pump is on the edge and cannot work hard enough to build pressure with the F1 fluid at warm temperature with less viscosity.

Does that sound good?

 

I went to do some diagnosis but the battery was dead (my bonehead move).

 

OK, more diagnosis data.

Line pressure: 42 bar to 56 bar. It never got to 60 bar before the pump is supposed to stop (at least that is what the manual says) But it does not sound strain and system was bled pretty well.
The pump turns back on after about 3 shifts and the line pressure drops to 42 bars. It runs for a few seconds and then stops at 54 or 55 bars and never got to 60 bar.
Engine off, shifts OK into 3 / 4 / 5 /6
Engine on (not even quite hot yet) it will not shift into 3 / 4 / 5 gear

The potentiometer travel for selection (a parameter I can read) reads high into 600-700 while the engine is not running and the gear box shifts good. It does not read that high while engine is running and does not seem to change value at all when the it does not shift into 3rd gear.

And something is definitely wrong with the hydraulic pressure system. When the engine is running, the line hydraulic pressure is bleeding down pretty quickly. Dropping 1 bar every couple seconds.

What other parameters should I be looking at?

Brake position is working. It is reporting the right state.

 

Leak rate is very high. Dropping 1 bar every couple seconds while engine is running. There are error codes stored:

1742, selection potentiometer
1770 Gear engagements with wrong shifts
0600 Can error code (may just be coincidental)
1760 brake pedal (may also be a fluke)

 

I will correct a previous data.

The system will allow two shifts before the pump turns back on, and it turns off again at 55 bar, never reaching 60.

Leak rate with engine off, in gear, is about 1 bar every 20 seconds,
Leak rate with engine on, in gear, is about 1 bar every 2 seconds.

By the way, I have a Launch X431 mini Pro. Please expand on what "relearn" is. With or without a scanner.

 

OK, So I got the scanner to initiate a Relearn. Did a PIS procedure, and an IO procedure. Turned the car off, back on, shift into 1, 2, but cannot go above 2nd gear. Failure mode remains.

 

Yes, it went through the gears and then beeped.

 

I found a diagnostic parameter called E-diff System Leak but when I selected it for display, it returned "no data available". So I timed the pump on and off interval. The pump cycles about every 1 minute. Hydraulic pressure drops below 42 bar and pump comes on for about 3-4 seconds, builds pressure to 55 bar and stops and stays off for about 50 seconds, then comes back on again.

So according to your comment, that is excessive.

I also forgot to add that when it was acting up while driving, the F1 gearbox warning light would flash on and comes off during the time that it did not want to shift into gears. I am under the impression that the F1 light comes on to signify low system hydraulic pressure.

 

Which sensor is the Selection Potentiometer? And btw clutch life is about 45% used up so supposedly plenty of life left.

 

1. I am a little concerned that it never gets to 60 bar and only generates 55 bar. That means the system lost more than 25% of its range of working pressure. 13 bar instead of 18 bar.

2. I have 10.95 software version. I think the 430 is better supported on the X431 tool than the 360

3. I will see if I can graph the leakage, but I don't remember seeing that as a parameter to report for the 360

4. If it is a solenoid, are they available individually or only as a power unit?

 

@Ray Smith , what is Stef's web site? I am not familiar with that.

 

Not yet, that is one of the things to do today.

 

I have two questions:

1. What is the point of line pressure where the computer will turn on the F1 warning light on the dash (the little icon that looks like the rear hatch is open)?
2. How does one get the motor to continue pumping until the line pressure reaches 60 bar ?