lugu50
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Dear Friend Ed:
As I can see maybe you are the only person who can help me. The case is that I need desperately a schematic for TCU installed on AW4 of my XJ Limited '88. Lot of trouble, had to change 2 transistors on TCU to correct reverse (which was not engaging on cold transmission, and now at last, 1-2 gear will not engage not in Drive lever position , nor in Lever 1-2 position. If I disconect TCU. 1-2 gear will engage.
Any help and or advices will be very apreciated.
Thanks,
Luis
Quote:
Originally Posted by Ed A. Stevens
FWIW,
I burned 1/2 Watt diodes isolating the current to the solenoids. I changed my installation to relays for physical isolation of the TCU and override current (no problems since).
When the diodes burned the TCU went into limp mode: 1st, 3rd, 4th and no TC lock. No 2nd (unless you drove through the shift override limit in the 1-2 position detent) and no TC lock in the default mode. The limp mode will get you home, but the unlocked TC generates considerable heat.
I like your project, although I'll defer the critique to the EEE's (BSME only here).
When you get to the TC lock/unlock control, and speed sensor logic for the relay for auto mode, can you make the unlock speed setpoint adjustable? This would be a great addition to keep the AW4 cool in 1st gear (a locked TC is not available in 1st with the TCU program). Maybe something for a future term project?
Happy Trails!
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As I can see maybe you are the only person who can help me. The case is that I need desperately a schematic for TCU installed on AW4 of my XJ Limited '88. Lot of trouble, had to change 2 transistors on TCU to correct reverse (which was not engaging on cold transmission, and now at last, 1-2 gear will not engage not in Drive lever position , nor in Lever 1-2 position. If I disconect TCU. 1-2 gear will engage.
Any help and or advices will be very apreciated.
Thanks,
Luis
Quote:
Originally Posted by Ed A. Stevens
FWIW,
I burned 1/2 Watt diodes isolating the current to the solenoids. I changed my installation to relays for physical isolation of the TCU and override current (no problems since).
When the diodes burned the TCU went into limp mode: 1st, 3rd, 4th and no TC lock. No 2nd (unless you drove through the shift override limit in the 1-2 position detent) and no TC lock in the default mode. The limp mode will get you home, but the unlocked TC generates considerable heat.
I like your project, although I'll defer the critique to the EEE's (BSME only here).
When you get to the TC lock/unlock control, and speed sensor logic for the relay for auto mode, can you make the unlock speed setpoint adjustable? This would be a great addition to keep the AW4 cool in 1st gear (a locked TC is not available in 1st with the TCU program). Maybe something for a future term project?
Happy Trails!
