Need expert AW4 help.

[bigalpha]

That sounds more like an issue of the transmission switch needing cleaning/adjustment.

Not so.

If you unplug the TCM, the AW4 defaults to like 4th gear in 'D'. You'll have to shift it by hand, from '1-2' to '3' to '4'. The trans WILL shift into '2', but it shifts at about 4k-4.5k RPMs.

The problem with the reverse lights and not starting in P is your NSS; search for it, it's pretty common.

Look up a document under the name of 'Shift Pointers' it gives diagnostic troubleshooting steps to what may be wrong. Post your results. lawsoncl is the trans guru around here so he may have more to say.

 

[lawsoncl]

Howdy. Someone call me? Don't know if I'm a guru, but I understand the electronic control aspect of the AW4 pretty well.

Not wanting to crank is Park is the Neutral Safety Sensor.
http://www.jeepin.com/features/nss/ or http://www.go.jeep-xj.info/HowtoNSSrebuild.htm

The NSS in a 98 might affect lockup or shifting into 4th. Skipping second gear does sound like a solenoid problem, so I'd start by measuring the resistance of the solenoids at the TCU connector. Here is a guide to help, although the pinout on the Trans Computer will be different. You want measure pins 11, 12, and 13 to ground.
http://www.transonline.com/transdigest/magazines/1997-10/Shift%20Pointers/index.html

 

[bigalpha]

Howdy. Someone call me? Don't know if I'm a guru, but I understand the electronic control aspect of the AW4 pretty well.

Not wanting to crank is Park is the Neutral Safety Sensor.
http://www.jeepin.com/features/nss/ or http://www.go.jeep-xj.info/HowtoNSSrebuild.htm

The NSS in a 98 might affect lockup or shifting into 4th. Skipping second gear does sound like a solenoid problem, so I'd start by measuring the resistance of the solenoids at the TCU connector. Here is a guide to help, although the pinout on the Trans Computer will be different. You want measure pins 11, 12, and 13 to ground.
http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html

It shouldn't skip 2nd if you are manually shifting it and you rev the crap out of it, though.

 

[lawsoncl]

It shouldn't skip 2nd if you are manually shifting it and you rev the crap out of it, though.

I have seen some folks posting that it won't upshift for them. I think it may have to do with the throttle-body cable adjustment as its the hydraulic pressure that forces the upshift. It might also vary a little by year?

 

[Matteo_96XJ]

This is similar to issues I've been chasing on my 96. It will sometimes stay in 4th gear after coming to a stop, sometimes likes to go into 2nd while on the freeway, once went into 1st at about 45 mph, and sometimes likes to switch between a locked and unlocked TCC while at freeway speeds. Needless to say, annoying and sometimes dangerous.

I've changed my solenoids and TPS, fluid is fresh and full, so I'll start looking at the grounds. I can always start it in P and N, and my reverse lights work fine.

Any other thoughts?

 

[cheros98]

allright thanks everyone , i'll start cheking like lawsoncl say and i hope to fix the problem not cost to much but no matter what it's my jeep

 

[lawsoncl]

This is similar to issues I've been chasing on my 96. It will sometimes stay in 4th gear after coming to a stop, sometimes likes to go into 2nd while on the freeway, once went into 1st at about 45 mph, and sometimes likes to switch between a locked and unlocked TCC while at freeway speeds. Needless to say, annoying and sometimes dangerous.

I've changed my solenoids and TPS, fluid is fresh and full, so I'll start looking at the grounds. I can always start it in P and N, and my reverse lights work fine.

Any other thoughts?

Although a bit rare, the trans computer can also be bad.

 

[Matteo_96XJ]

Although a bit rare, the trans computer can also be bad.

Funny you mention it, I was told the main PCM controlled the trans.

Where is the trans computer located?

 

[lawsoncl]

I'm not sure what year it moved. The older Jeeps had it under the passenger side of the dash, and I understand the newer years have it on the drivers side above the gas pedal.

 

[Matteo_96XJ]

I'm not sure what year it moved. The older Jeeps had it under the passenger side of the dash, and I understand the newer years have it on the drivers side above the gas pedal.

That gives me 2 places to look. Thanks.

 

[Matteo_96XJ]

My apologies for resurrecting a dead thread. Hasta

After chasing my tranny troubles for several years, I finally decided to try a 'new to me' TCM. It fixed everything.

 

[joe_peters]

Searching and adding to old threads is EXACTLY what should be done if the problem is similar, and that leaves more info for the next person with a similar issue that is searching on .

NECROPOSTING, or providing input to a thread when it is obvious the issue was resolved some years ago, is another--and entertaining--thing!

 

[Ecomike]

My apologies for resurrecting a dead thread. Hasta

After chasing my tranny troubles for several years, I finally decided to try a 'new to me' TCM. It fixed everything.

HMMMM, if you resurrect it, it's not dead!!!!!

How you doing these days Joe?

 

[joe_peters]

HMMMM, if you resurrect it, it's not dead!!!!!

How you doing these days Joe?

Pretty good, working on more guns than cars at the moment.

I have to fix my tilt column in the XJ tomorrow--when they come loose they go from bad to really bad darn quick.

 

[Ecomike]

Yes they do, kinda like dropping something off the side of a cliff. The end comes real fast, if you don't stop and fix it.

 

[praetorian]

I'll ask this here too. On my buddies 98 I can't get any resistance or continuity on his #2 solenoid. If a solenoid goes bad will it also loose continuity?

 

[lawsoncl]

I'll ask this here too. On my buddies 98 I can't get any resistance or continuity on his #2 solenoid. If a solenoid goes bad will it also loose continuity?

Usually it'll read very high resistance or as an open circuit.

 

[bigalpha]

Check continuity from the connector next to the firewall in the engine bay.

 

[Ecomike]

Check the meter battery. You can't loose continuity and resistance at the same time. make sure you have the probes in the right meter spots too.

 

[praetorian]

Check continuity from the connector next to the firewall in the engine bay.

Yes, I also checked from the connector next to the firewall. I'm getting continuity and resistance from the T/C lockup solenoid and #1 solenoid, just not the #2, at either location. I just haven't dropped the pan yet.