Hi guys

I could do with a bit of advice here. My Jeep has started idling rough after I changed the alternator - guessing that this is just the ecu re-learning idle after battery was disconnected. Trouble is, it's been a good few days of driving around since and it still tries to stall on me when I take foot off the gas. The IAC was cleaned around 6 months ago - may need replacing?

The Jeep gremlins decided overnight to give me another issue to look at. Sometimes it won't change out of first gear, sometimes it drives great.

I hooked up my scanner and found a pending fault code of p0756 - solenoid B. Do I listen to what the heep is trying to tell me and replace this solenoid, or could this code be caused by anything else?

If I do change the solenoid, should I change all 3? There are also quite a few choices of solenoids out there from what I can see - I have no idea how these solenoids work or how reliable they are, should I avoid the cheap ones? What brand do you guys go for?

Thanks

 

[QUOTE=97jeepxj40;2750929]Hi guys

I could do with a bit of advice here. My Jeep has started idling rough after I changed the alternator - guessing that this is just the ecu re-learning idle after battery was disconnected. Trouble is, it's been a good few days of driving around since and it still tries to stall on me when I take foot off the gas. The IAC was cleaned around 6 months ago - may need replacing?

The Jeep gremlins decided overnight to give me another issue to look at. Sometimes it won't change out of first gear, sometimes it drives great.

I hooked up my scanner and found a pending fault code of p0756 - solenoid B. Do I listen to what the heep is trying to tell me and replace this solenoid, or could this code be caused by anything else?



The two problems may be un related. The stalling issue is definitely battery related. Have a good look at every battery connection (follow the leads and look where they connect) and clean them all very well. you most likely disturbed a connection somewhere when you replaced the altenator. check all connections as that could have been the reason the alt failed to begin with. as far as your trans issue... that could very well be the pcm acting up from resetting so give it a few after you have resolved the electrical issue

 

If your trans shifting problems don't sort themselves out you can check the solenoids for the amount of resistance they show. Here's what I did when I replaced mine. I just replaced the two shift solenoids, they have been working fine for over a year. I used Rostra because they're made here.

Transmission Solenoids-Checking
There's a way to check the AW4 transmission solenoids without dropping the pan. It’s not foolproof because high resistance may be caused by loose/corroded/dirty connections, etc.

There are two connectors at the firewall (passenger side) that go to the transmission. one will be an 8-way, the other a 6-way. You’ll want to check the 6-way. Pull the connector apart and with a digital meter check the resistance at the terminals leading to the transmission. All three should read between 11-15 ohms. That’s a narrow operating range, so touch your meter’s leads together and see how much resistance is in your meter’s leads. The will also be some resistance through the connectors and the wires leading to the solenoids, but my guess is that if the connections and wires are good there shouldn’t be more than about one ohm of resistance.

The other way to check is to pull apart the wire harness at the TCM (transmission control module) usually referred to as the TCU. Look or research for its location. Mine is under the dash near the steering column. The harness connector should have 26 cavities, two row of thirteen. The solenoid cavities are on the top row (with the harness lock facing up), the last three on the right (#11, 12 and 13). With a good chassis ground, measure the resistance from the cavities to the ground. I’m not sure what years this applies to but it is the way my ’97 is set up.

However, if you’re in need of a transmission service the best way to check the solenoids is to check their resistance at the individual solenoids by pulling the connectors off and checking the resistance from the male spade connector on the solenoid to the bracket. Keep in mind that it may take anywhere from overnight to a week to get a replacement part so your vehicle may be down for a while if you find a bad solenoid. Or you can button it back up and put the old oil back in and shift it manually till the parts arrive. Prices vary wildly from about $80 to $240, Jeep and NAPA are the most expensive, but you usually get what you pay for.

Cheers.


Trans Solenoids-LINKS
makcotransmissionparts.com
Three Solenoids
http://www.makcotransmissionparts.com/97420K.html
Rostra # 52-9002 $224.95
Made in USA


BulkPart.com
Three Solenoids
http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=CTGY&Store_Code=2&Category_Cod e=A340solenoid


Rostra # 52-9002 $224.95
Made in USA
Two Solenoids
http://www.bulkpart.com/2/product/A340solenoid/67420CK.html
Code: 67420CK
Price: $124.95


TCC Lockup
http://www.bulkpart.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=97425
Code: 97425
Price: $75.10

Transmission Parts USA
http://www.transmissionpartsusa.com/AW4_A340_transmission_solenoids_kit_Toyota_p/940-00094393a.htm
Cost $192.50
Free shipping over $125
Email to company: Solenoids are imported

Rostra Transmission Parts Website
http://www.rostratransmission.com/transmission-solenoids-by-rostra-transmission.php


Installation Instructions Toyota A340/Jeep AW4 transmissions
http://www.rostratransmission.com/manuals/Form4187E.pdf

 

Well, one thing that could be involved with BOTH issues is your TPS...and yes...the.code is your Jeep trying to tell you something yes..

 

To check your shifting issue further, ' disconnect/unplug the TCU and shift manually. If it shifts fine then, the cause of your shifting issue is electrical. I bed it will.

When changing solenoids, you might as well do all three of them, once you're in there.

The ECU runs of pre-set programs if the battery has been disconnected.
In my experience it should not be keeping the rough idle becaus you disconnected the batt. So the rough idle/stalling is not because of this



But: you state that the issues started after you replaced your alternator.
Rule #1 with issues after work done is: check the work that has actually been done

Did you knoch anything off, broke a wire, disconnected and did not reconnect?

Have you actually checked your alternator , to see if it works?
Is your battery charging?

Many leads and different approaches....

 

As stated above, don't rule out the TPS, it will also account for rough idle. I have been through a couple this past year, if you must buy from a parts store be sure it is a BWD brand.

 

Yep, like I stated, TPS is also involced in shifting charateristics.
For TPS I'd source a good quality one, like from the dealer. Much like the CPS.
Aftermarket is...well, like you know by now, you'll see yourself going through several...