• Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.

Transmission control unit

598BBC

598BBC

NAXJA Forum User
Location
Hemet/ so cal
Tried doing a search to no avail, My dilemma is ...I had a small fire inside My vehicle which burnt the TCU and some wiring amongst other things, anyhow I was able to cut the stock wiring harness back from the unit about 6", at that time the vehicle would move but only in high gear.. I recieved another TCU unit out of an 89 jeep cherokee and was able to splice all wires and make a clean set-up, My question is:confused1 is there a difference in the Yrs, My cherokee is a 94 and now all I have is 1st gear. Any suggestions or help would be greatly appreciated Thanks
 
could you please explain... maybe I have missed something.. Thanks
 
598BBC said:
Tried doing a search to no avail, My dilemma is ...I had a small fire inside My vehicle which burnt the TCU and some wiring amongst other things, anyhow I was able to cut the stock wiring harness back from the unit about 6", at that time the vehicle would move but only in high gear.. I recieved another TCU unit out of an 89 jeep cherokee and was able to splice all wires and make a clean set-up, My question is:confused1 is there a difference in the Yrs, My cherokee is a 94 and now all I have is 1st gear. Any suggestions or help would be greatly appreciated Thanks
Click to expand...


Yes they are different.The 87-90 TCU had a direct signal from the old style dual sided TPS sensor on the throttle body. IIRC, The 91+ went to a single side TPS sensor that only connects to the ECU, then the ECU translates and then sends its own signal to the TCU regarding TPS position. So the wiring, part of it anyway, and the TCU are a bit different indeed!
 
Last edited:
does anyone happen to have a TCU laying around for a 91-95 cherokee.. Thanks
 
Yup, you need a 91-95 TCU. The TPS input changed from the Renix setup with the dual-output TPS sensor. The input in the HO and up matches what the ECM gets (0->5 volts vice 5->0 volts). I believe a 96/97 TCU might work too, but I have some conflicting info about when other sensor changes happened. Changes definitely happen in 98.
 
598BBC said:
does anyone happen to have a TCU laying around for a 91-95 cherokee.. Thanks
Click to expand...

Try Ebay! or the local JY, they should be very common.
 
598BBC said:
does anyone happen to have a TCU laying around for a 91-95 cherokee.. Thanks
Click to expand...
More than I'd pay, but here's one on eBay http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=230206841496

For reference, you want one with a green connector. The Renix era ones had a grey connector. The ones from a 93 ZJ might work - again look for the green connector as red(?) would have been the chrysler tranny.

Sell the other one off on eBay too, btw.
 
You must log in or register to reply here.

Similar threads

D
Temp Gauge Reads High With New Senosr
Replies
15
Views
1K
TheDXJ
T
M
1992 Electronic Control Module - Can these be purchased new anymore?
Replies
8
Views
171
lawsoncl
L
G
Red and Purple ignition wiring hot to touch with A/c and blower on high
Replies
0
Views
1K
gmcchamp99
G
D
No Start, P1694. Tons of work done, not sure where to start
Replies
9
Views
2K
Saudade
Saudade
B
2000 4x4 sport with 4.0 auto trans issues looking for help.
Replies
4
Views
1K
lawsoncl
L
Back
Top