Solenoid voltages
1 - 9 of 9 Posts
Joined
·
2,520 Posts
Solenoids EDS 2 (B clutch) & EDS 5 (main pressure) should both be activated in Park, to disengage the B clutch and modulate system pressure.
MV1, EDS 1 (A clutch), EDS 3 (C brake), EDS 4 (D brake) and EDS 6 (torque converter LUC) solenoids should all be ‘off’.
The D brake is the only friction element engaged in Park (& Neutral).
![]()
Phil
MV1, EDS 1 (A clutch), EDS 3 (C brake), EDS 4 (D brake) and EDS 6 (torque converter LUC) solenoids should all be ‘off’.
The D brake is the only friction element engaged in Park (& Neutral).
Phil
Ok what i am seeing is 1-0.05a 2-0.85a 3-0.05a 4-0.65a 5-0.78a 6-0.05a. but i should not be seeing 4 active in park? Theses are the values i get live from the code reader. I have not found anywhere that list what these values should be. I have not been able to figure out why the transmission is not circulating the fluid. the only code i have is p0730.
Joined
·
2,520 Posts
The threshold current for the solenoids is 48mA so a reading of 0.05A means that the solenoid is ‘off’.
Maximum current is around 850mA, so 0.85A is ‘fully on’, with any current in-between (i.e. from 48mA to 850mA) providing a modulated pressure.
The solenoids for the 6HP26 come in three ‘types’. The MV (black cap) solenoid is a simple ‘on-off’ solenoid. The remaining six solenoids are proportional pressure devices and come in two varieties – blue cap and yellow cap.
![]()
![]()
The yellow cap solenoids (EDS 1, 3 & 6) produce no pressure when no current is applied, and their pressure then increases with current.
The blue cap solenoids (EDS 2, 4 & 5) do the opposite. They produce full pressure at zero current and the pressure then falls as the current is increased. A very common application for this type of solenoid is for the modulation of mains pressure. If there is an electrical/electronic failure, then the transmission defaults to maximum pressure to allow limp-home.
This leads to the slightly confusing situation where, when a blue cap solenoid is ‘off’ (no current), it is therefore ‘on’ (providing full pressure). You can see in the table that EDS 2 is applied to disengage the B-clutch. Similarly, EDS 4 controls the application of the D-brake and the E-clutch and is therefore applied in 2[SUP]nd[/SUP] and 3[SUP]rd[/SUP] gears to disengage both of these friction elements.
Phil
Maximum current is around 850mA, so 0.85A is ‘fully on’, with any current in-between (i.e. from 48mA to 850mA) providing a modulated pressure.
The solenoids for the 6HP26 come in three ‘types’. The MV (black cap) solenoid is a simple ‘on-off’ solenoid. The remaining six solenoids are proportional pressure devices and come in two varieties – blue cap and yellow cap.
The yellow cap solenoids (EDS 1, 3 & 6) produce no pressure when no current is applied, and their pressure then increases with current.
The blue cap solenoids (EDS 2, 4 & 5) do the opposite. They produce full pressure at zero current and the pressure then falls as the current is increased. A very common application for this type of solenoid is for the modulation of mains pressure. If there is an electrical/electronic failure, then the transmission defaults to maximum pressure to allow limp-home.
This leads to the slightly confusing situation where, when a blue cap solenoid is ‘off’ (no current), it is therefore ‘on’ (providing full pressure). You can see in the table that EDS 2 is applied to disengage the B-clutch. Similarly, EDS 4 controls the application of the D-brake and the E-clutch and is therefore applied in 2[SUP]nd[/SUP] and 3[SUP]rd[/SUP] gears to disengage both of these friction elements.
Phil
Eds 4 should be ‘off’ (no current) in park but it is seeing current. So ether its bad or something else is shorted sending it current. I asked before if have to replace Eds 4 should i replace the rest?
Joined
·
2,520 Posts
I wouldn’t have thought that replacing the solenoid would fix the issue if it’s being incorrectly supplied with current. What exactly is the problem that you’re having, that’s lead you to investigate the solenoid actuations? You haven’t disturbed the mechatronic unit in any way have you?
Are you able to take the solenoid current readings in Reverse, Neutral and Drive when stationary, as well as Park?
Phil
Are you able to take the solenoid current readings in Reverse, Neutral and Drive when stationary, as well as Park?
Phil
I can take reading those readings. I know that Eds 4 drops to 0.05a at drive and reverse and back up to 0.65a to 0.85a at park and neutral. the only thing i did was change the sleeve to the connector. I sprayed it with electronic contact cleaner and used a plastic pick to remove some old oring to get the sleeve to fit right. My finger did touch the pins. I thought that if the solenoid was turning on and off backwards it would be the solenoid. As i said the only code i was getting was p0730. Then the fact i could only get 3 quarts back into the tranny were the only things i had to go on. there is little in the forums but what was there pointed to replacing the solenoids.
1 - 9 of 9 Posts
