Strokermjcomanche Posted August 6, 2014 Share Posted August 6, 2014 Went on a couple errands this morning and everything is working as normal . Stopped at an intersection , accelerated and the engine revs out to 5-6000 rpms without the trans shifting into second gear and I have no speedo either . If I let off the gas after going I'm guessing? 20 mph it will shift into second gear but has no passing gear . Once I get to maybe 45 - 50 mph and give it full throttle the engine will rev really high but the trans will not find a gear unroll I let off the throttle again . So far I've taken all the grounds, the two trans plugs,and the tcm plug and cleaned them all . I've also checked all the fuses for power . I've also checked for trouble codes and found nothing . The drivetrain is out of a 95 xj with 97xxx miles on it . I've recently replaced the vss and have a good known spare that I'm gonna try tommorow . I'm wondering if it's that or the tcm or??? Any help is much appreciated as always . Thanks for reading . Link to comment Share on other sites More sharing options...
88ComancheMitch Posted August 6, 2014 Share Posted August 6, 2014 What about the gauge cluster itself? Link to comment Share on other sites More sharing options...
Jeep Driver Posted August 6, 2014 Share Posted August 6, 2014 TPS Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 Mitch : I don't see how the cluster would stop the trans from shifting . I would like to know of a way to double check though as I don't want to throw any parts at it unless I already have a spare to try ( and unfortunately I don't ) . Jeep driver : I can imagine how the tps would effect the trans but can't see why I wouldn't have a speedo . Any idea what voltage I'm supposed to have at the tps wires ? I have a 90 (renix) but not for 95 h.o..I have a multimeter Link to comment Share on other sites More sharing options...
Eagle Posted August 6, 2014 Share Posted August 6, 2014 Fuse(s)? A '95 would be an electronic speedometer if you swapped everything over from the donor vehicle. There's a fuse for that. There's also a fuse for the TCU, and if that fuse is pulled you can shift it manually but you only get three gears instead of four. Or maybe the speed sensor in the transfer case is stripped (the gear is plastic) so the whole system just isn't getting any speed information. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 Eagle : I checked all the fuses and all of them have power . I plan on changing the vss today and will also inspect the gears . This driveline has been in my other truck as well for 30k and never had an issue until now . I'll let you know if the vss works and was trying to see if I should check anything else . Thanks Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 I have another question . There is a sensor on the trans behind the 4wd shifter bracket on the drivers side of the trans . What does that control ? Could that be the culprit? Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 6, 2014 Share Posted August 6, 2014 That is the output speed sensor and the sensor itself or it's wiring could very well be the cause of your problem. It's a reed switch that reads the output shaft RPMs and sends the signal to the TCU for the shifting points. It can also cause your speedometer not to work. It's a major bear to replace on a 4WD because of it's location. BTW, you mentioned your drivetrain is from a 95? Does it use the HO wiring or Renix? Thinking fault codes.......... Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 Thanks Hornbrod . It's the complete h.o harness minus the part that goes to the tail lights . The sad part is when I did the swap I had the shifter bracket off and if I knew what I know now I woulda changed it due to the fact of how easy I could get to it . I'm going to clean the connector to that sensor and take the 5minutes to change the vss being I have a good spare . Is there any way to check that sensor? Btw I have my own code reader ( innova 3160) and no codes came up related to the trans / speedo issue . Unless it's not capable of reading them . Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 6, 2014 Share Posted August 6, 2014 Is there any way to check that sensor? Yes. You will have to jack up the wheels though. Disconnect the sensor and hook up an ohmmeter across the pins. Rotate the wheels. The meter should "pulse" once per shaft revolution as the magnet on the output shaft passes the reed switch tip. This isn't an infallible test however. I once had a no speedo problem and tested the sensor this way (it's in the FSM) and it tested good. After eliminating other possible causes of speedo failure I could think of, I replaced the reed switch anyhow and the speedo started working again. :dunno: Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 Can I rob one off a good renix? Got a part # if not I can't recall ever looking up one at the parts store just look for a reed switch? Thanks again for the help . Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 6, 2014 Share Posted August 6, 2014 Part number is 83503722, fits 87-97, so should work. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 6, 2014 Author Share Posted August 6, 2014 Cool thanks Don . I'll just leave the 4wd bracket and shaft off until I can confirm it works then I'll install a brand new one . Time to go take a nap under the truck lol. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 13, 2014 Author Share Posted August 13, 2014 Update : After double checking all the grounds I started checking the rest of the wiring and noticed a couple coroded wires on a 5 wire plug by the trans plugs and by the trans dipstick . I had to cut about 6 inches of wire and solder and heat shrink everything back together . Now I have a speedometer but the trans still shifts irratically . I replaced the vss and the reed sensor with good known spares and nothing changed . I hate wiring and I'm at wits end . Should I try a new tcu ? I'm not sure what else to do . Thanks in advance . Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 13, 2014 Share Posted August 13, 2014 Btw I have my own code reader ( innova 3160) and no codes came up related to the trans / speedo issue . Unless it's not capable of reading them . Bummer. You say you are a complete 95 HO harness except for the tails. So, depending on what cluster you have, have you tried the IGN key sequence to check for OBD1 fault codes? I don't know what your Innova reader reads. AFAIK, the only code reader that can show OBD1 fault codes is the dealer proprietary DBRIII reader using the test port. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 13, 2014 Author Share Posted August 13, 2014 It's the newer cluster . Currently there is no check engine light but I'm going to go try to see if anything displays . Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 13, 2014 Share Posted August 13, 2014 http://comancheclub.com/topic/28111-reading-obdi-91-and-92-mj-fault-codes/ Link to comment Share on other sites More sharing options...
deziped1 Posted August 13, 2014 Share Posted August 13, 2014 Have you back probed the TCU to verify the 3 shift solenoids are good. Several times in past how to do this has been posted on here. try search for transmission shift solenoid OHM check. Under hard (full) throttle the 1st to 2nd shift occurs around 4500 - 4800 RPM. If the 1st to 2nd solenoid is failing it won't shift to 2nd. 2nd to 3rd gear won't happen either if that solenoid is shot. If last one is shot it won't lock up the T converter either. All of those can be tested through the TCM without removal of tranny pan. I'd borrow a known good TCU and try it. It only takes a couple minutes (plug & play) Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 13, 2014 Author Share Posted August 13, 2014 Came up with a code 15 . But is that because the wiring was faulty and it hasn't went through the 50 cycles yet? Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 13, 2014 Share Posted August 13, 2014 No. You have an open or short (wiring problem) from the speed sensor to the ECU or the branch circuit to the TCU causing your AW4 shifting problems. Your Innova code reader is for an OBD2 system - useless here. Since you have a 95 OBD1 harness/system (I think ?), you need to start from the speed sensor point-to-point continuity checking to see where the fault is. To do that you will need an accurate wiring diagram / FSM for whatever you have installed. Link to comment Share on other sites More sharing options...
Strokermjcomanche Posted August 13, 2014 Author Share Posted August 13, 2014 Thanks Don . I see a lot of swearing in my future . I hate wiring and really hate reading diagrams . Do you think that since my alternator voltage is low and controlled by the ecu as I posted in the other thread that if I check all the wiring for continuity and it checks out fine that my ecu is bad ? Link to comment Share on other sites More sharing options...
HOrnbrod Posted August 13, 2014 Share Posted August 13, 2014 Bad ECUs are rare. Since you have only one fault code which points to exactly the problem you are having, your ECU should be fine. Otherwise there would be more codes and/or drive-ability issues. Occasionally the 60-pin ECU connector pins can get depressed especially if it's been disconnected and reconnected many times, so do a good eyeball check for that. Spray some good contact cleaner to both sides also. Your symptoms all point to an open circuit from the AW4 speed sensor signal to the ECU to me. Link to comment Share on other sites More sharing options...
Incommando Posted August 13, 2014 Share Posted August 13, 2014 Gawd tracing wiring faults is tedious. Good luck. Link to comment Share on other sites More sharing options...
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