Scangage II Question

thewalker350 · **Posted:** Mon Jan 07, 2008 11:12 am

I have a question for people who are using their Scangage II on a regular basis. When I plugged in my Scangage II before our Christmas road trip everything worked great. I wanted to drive around town to get good numbers for baseline data. I started to have problems with the transmission downshifting on its own when in cruise. We took the road trip to Ohio and the transmission would downshift then upshift for no reason. Conditions did not warrent the downshift as the speeds were 70 MPH and flat level roads at the time and no head winds. On the return trip to Florida I unplugged the Scangage about halfway home and the transmission hasn't acted up since. I was wondering if anybody else has had this issue or can figure out if the Scangage can cause an uncommanded downshift. I don't want to plug in the Scangage to see if comes back as it really downshifts hard and I don't want to damage any driveline components. :roll:

ATXKJ · **Posted:** Mon Jan 07, 2008 12:12 pm

retmil46 posted this in another thread

Quote:

Did have one OMG moment - about 30 miles south of Dallas, 70 mph on cruise, there was a loud bang, the tranny dropped out of gear and lockup, and engine rpm dropped to idle. Gave it throttle and once rpms were back up it went back into gear and lockup, and cruise reengaged without a problem.

I'd noticed a few times when tapping the accel button to bump it up 2 mph, it only went up 1 mph, and when I gave it a second tap, it'd jump up 3 mph. I called my tranny guru back in NC and described what had been happening, including dropping out of gear. He said it sounds like the speed sensor on the tranny output (not the one on the rear diff) is putting out a weak or erratic signal - that would explain both the screwy cruise control and dropping out of gear.

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?p=282610#282610

sounds like the same thing - I don't think the Scangauge is a factor - although it remains a possibility until it happens to someone without a scangauge.

retmil46 · **Posted:** Tue Jan 08, 2008 12:17 pm

Last Saturday I went by the tranny shop so Bruce could hook up a scanner and see if the tranny had thrown any codes that didn't show up as a CEL or with the odometer trick.

What he found was P0884 - Power-Up During Run. Way that Bruce explained it to me, the TCM was momentarily losing power and then rebooting while driving down the road. He said this could be caused by a loose connector, or even just a loose fitting individual pin and socket on one of the connectors.

Mine has done this a total of 4 times now in the last 3500 miles, all at odd times and with no apparent pattern. First time was driving home at 45 mph on a secondary road, no lockup or cruise control. Second time was what I reported above. third time was while I was still in TX, 70 mph on I-35, in lockup but no cruise control. 4th time was when I was on the way home last week, over 1000 miles since tha last occurrence near Hickory NC on I-40, 70 mph with lockup and cruise control.

Bruce siad the intermittent power loss would explain it's occurrence regardless of whether or not I was in cruise control. He said the odd behavior at times of the cruise accel button may be a separate issue, related to a early TSB concerning the clockspring in the steering wheel.

I'm taking it in early tomorrow morning to his shop so they can put it on a lift, check out all the connectors, and give it a good going over.

Back on Sunday, I pulled my Provent so that he could get access to the TCM and it's associated connector. You could see where the Provent had been rubbing against the top cover of the connector. The top side of the connector was also covered with a good layer of caked dirt, which I cleaned off somewhat with spray MAF cleaner. Using a small 1/4" ratchet and 8 mm socket, I checked the mounting bolt for the connector. It was loose enough that I was able to get somewhere between 1 to 2 full turns tightening the bolt with just 2 fingers on the ratchet.

In addition, there was a small extrusion on the plastic frame of the boost controller, where the boost controller harness was tystrapped to, that was pressed hard up against the TCM connector. I'm guessing that they didn't mount the boost controller in exactly the right location. I used a pair of wire cutters and snapped off this extrusion, such that there is now somehwere between 1/2 to 1 inch clearance between the boost controller frame and the TCM connector.

retmil46 · **Posted:** Tue Jan 08, 2008 12:33 pm

Just called up Bruce and told him that someone else on the list was having similar problems as well, and floated the Scangauge II theory to him, as I've been using one as well and also haven't had any odd behavior prior to using the Scangauge II.

He said this was a definite possibility, that some aftermarket devices such as the Scangauge could cause glitches that could cause the TCM to reboot itself, in effect simulating a loss of power and throwing the P0884 code he found.

thewalker350 · **Posted:** Tue Jan 08, 2008 1:11 pm

After I removed my scangage it hasn't dropped out of lockup and mine would only do it with cruise on. I'm going to check the hardware that you found loose to rule that out. If it happens again without the Scangage installed, I'll take it in to the dealer and see what they say. I just hate to deal with the dealer and their stupid answers. Thanks for the info.

clday25 · **Posted:** Tue Jan 08, 2008 3:28 pm

Add me to the list.... With my Scangauge hooked up, I've had the same type of bang and drop out of gear issue happen twice in the last month or two. First at 70 mph on a flat section of I-5 and again a couple weeks later at around 45 mph.... very disconcerning, especially with the wife in the Jeep giving me a look questioning the $$$ I've "invested" in my tranny....

Not that this is a good thing, but i feel better knowing I'm not the only one that's experienced this. I'm gonna check my TCM connections and keep the Scangauge hooked up to see if it happens again.....

Chris

bugnout · **Posted:** Tue Jan 08, 2008 4:56 pm

Never had a problem or found any issues that I could correlate to having the SGII connected. As long as you don't count loosing com.

The only time I have experienced the symptoms you describe was due to fuel. Engine hickups and the tranny downshifts. Changing the fuel filter solved it. Never got any codes so doesn't sound the same.

Cowcatcher · **Posted:** Tue Jan 08, 2008 7:47 pm

I have had it happen several times. The first time or two was pre-ScanGaugeII and sometime back. I have probably had it happen four times in the last two months though, generally in cold weather and shortly after initial TC lock up. Others told me that it was likely that the tranny fluid wasn't warm enough yet. Hadn't considered the SGII and it didn't happen when it was connected in warm weather.

retmil46 · **Posted:** Tue Jan 08, 2008 9:10 pm

One thought occurred to me - for the first two months or so I had the Scangauge installed, I was simply using it as a gauge - I wouldn't bother clearing the CEL for the ORM. No wierdness from the tranny.

The first instance of this happening didn't occur until after I got into the habit of clearing the ORM CEL upon startup.

From what Cowcatcher has reported though, and what I saw checking out the TCM connector, I still wouldn't discount Bruce's loose/dirty connector call from at least contributing to the problem. Might be a combination of the two is enough to start causing problems, whereas either by itself wouldn't.

Talking with Ranger1 tonight, he said that the TCM and ECM share that same data bus with other functions - such as speedo and cruise control. If the Scangauge is throwing out enough garbage/noise to cause the TCM to periodically reset itself, he felt that might also explain the odd behavior with my cruise control and speedo that I mentioned.

I'm dropping the beast off at the tranny shop tomorrow morning, I'll let you know what they find.

geordi · **Posted:** Wed Jan 09, 2008 12:45 am

While towing with the SG connected, mine has done exactly the same thing. Cruise at about 68-70, then Bang, drop out of gear, engine to idle.

It did it twice with no apparent reason, and hasn't done it since I got to my destination, and haven't towed since. The SG is still connected full time. Also, the dang thing would lock up on me if the tranny downshifted for a hill b/c the cruise told it to. Other than that, it didn't seem to lockup unless the engine was being asked to rapidly change operational speed for something. Slower acceleration seemed to not cause any problems for it.

I think we need to get the SG guys in on this, it sounds like an incompatibility in the data stream somewhere. Isn't the SG supposed to be a passive observer, not an active participant in the OBD datastream?

retmil46 · **Posted:** Wed Jan 09, 2008 7:00 pm

Got the Jeep back from the tranny shop a while ago. All the connectors were good to go, they couldn't find anything out of the ordinary. Also had them swap out the oil in both axles and the transfer case to Amsoil, and they did a good inspection of the rear axle given what had been happening. In their words, it was "virtually spotless", no metal, dirt, or debris - just good clean oil.

So far, all indications are pointing towards the Scanguage causing this in some way, shape, or form.

One other common occurrence I've heard mentioned is that this also seems to happen after swapping to different tires, but I'm at a loss to explain how just switching to a different diameter or width tire would cause the TCM to reset itself while driving. Not everyone who has swapped tires has had this occur.

gmctd · **Posted:** Wed Jan 09, 2008 8:17 pm

It's bus contention - when ECM sez come read TCM, all the other modules hush, according to procedure, so the TCM driver can use the bus to respond - SGII wasn't invited to the party, so just keeps on hogging the bus instead of politely waiting for another opening to do it's thing

Only difference in the Bosch\Cummins CP3 system and the Jeep CRD CP3 system is Jeep has the rail pressure bypass solenoid, the intelligent turbo, and the intelligent(?) EGR routines - Dodge has a TCM and all the tuner boxes work with Dodge - even tho there's two cylinders worth of time left over in the Jeep 4cyl system, the SGII may never be able to get a word in edgewise without causing some contention - note that it locks up less when the scan update time is reduced

DarbyWalters · **Posted:** Wed Jan 09, 2008 9:54 pm

Just a simple question. Those that have the overhead display...I think you could get one in a CRD Limited...the display for mpg average/instant mpg/ect work without interuption. Makes me wonder why the Scan Guage II doesn't?

gmctd · **Posted:** Wed Jan 09, 2008 10:59 pm

It's invited to the party, optional part of the system, talks to the Body Control Module via the CAN comm buss, not the Diagnostic link.

Cut'n'paste ain't workin, so.............

Scanners talk to the ECM thru the DLC via a Serial Controller Interface, or K line - ECM talks to the other modules thru the CAN buss and the PCI buss, depending on what data is required - problem arises when the Diagnostic link is used to poll data from one of the other busses, which are constantly active as the other modules are trying to communicate with each other - the CAN buss talks at 500kb\s, the PCI buss talks at 10kb\s, further complicating realtime data on the DLC

Diagnostics and Flash uses any of the three busses, depending on the module being serviced, f'rinstance K-line to the ECM, which talks PCI to the BCM, CAN to the ABM, SCI\PCI to the TCM

DLC is a separate and specific K-line input to the ECM, which pulls Diagnostics from the TCM via it's Serial Controller Interface - TCM pulls some diagnostics from associated modules thru it's PCI buss.

However, ECM also communicates with the TCM via the PCI buss, not the hi-speed CAN buss.
ECM and BCM communicate via CAN buss - BCM talks to TCM via PCI buss.

Confused? The Autoenginuity scantool requires a custom intelligent adaptor on the DLC to retrieve realtime enhanced data from the various systems - standard OBD2 stuff is direct-connect for not much more info than the SGII gets.

I did not see Autoenginuity lock up with the enhanced adaptor, and I was polling for 9 to 12 enhanced data points simultaneously - I did not use the standard OBD2 connection for any length of time, so don't know if it would lock up, or not.

Hope this is helpful to all (snicker!)...................

But, wait - there's more....

Pin 2 - J1850 Bus+
Pin 4 - Chassis Ground
Pin 5 - Signal Ground
Pin 6 - CAN High (J-2284)
Pin 7 - ISO 9141-2 K Line
Pin 10 - J1850 Bus
Pin 14 - CAN Low (J-2284)
Pin 15 - ISO 9141-2 L Line
Pin 16 - Battery Power

retmil46 · **Posted:** Thu Jan 10, 2008 3:43 pm

Quick visual check on the TCM connector - when mine was loose, there was a visible gap between the two halves of the connector, such that you could see inside where the wires were running to their individual pinouts, and the top half of the connector could be moved around easily.

Once I tightened it down, the gap went away, the two halves were snug on each other, and the bottom half of the connector visibly pulled down further onto the TCM itself.

If the top half of the connector can be wiggled around, or there's a gap between the two halves, you probably need to snug down the mounting bolt on it. Nothing excessive - 2 fingers with a small 1/4" ratchet and 8 mm socket got mine quite snug.

Cowcatcher · **Posted:** Thu Jan 10, 2008 8:18 pm

DarbyWalters wrote:

Just a simple question. Those that have the overhead display...I think you could get one in a CRD Limited...the display for mpg average/instant mpg/ect work without interuption. Makes me wonder why the Scan Guage II doesn't?

I think part of the issue is SGII polls and the EVIC just reports. Due to the nature of the system in the CRD is goes bonkers after a cerain number of polls them loses data from all but a few of the reporting sources like RPM.

chrispitude · **Posted:** Fri Jan 11, 2008 9:05 am

gmctd wrote:

I did not see Autoenginuity lock up with the enhanced adaptor, and I was polling for 9 to 12 enhanced data points simultaneously - I did not use the standard OBD2 connection for any length of time, so don't know if it would lock up, or not.

Hi gmctd,

Would this be something that you could check for me at some point? I'm considering an Autoenginuity over the Scangauge. If the basic AutoEnginuity package will work without lockup, I'd obviously prefer to go that route.

I'm just looking for something to read coolant temperature and transmission temperature while towing, and I don't really want to deal with lockups and engine restarts in that situation...

I've also got an email in to them, and will share anything I learn.

- Chris

gmctd · **Posted:** Fri Jan 11, 2008 11:08 am

Yeah, but don't hold your breath, Chris - I seldom see that KJ since I healed it - I have so many questions answerable only with a scantool, even more with a 'scope, even more with just hands-on - I guess, just like DCX, I shoulda engineered some planned obsolescence into the fixes, so it'd havta come back in every so often - sometimes, it's hell to be good.....................

chrispitude · **Posted:** Fri Jan 11, 2008 11:29 am

gmctd wrote:

Yeah, but don't hold your breath, Chris - I seldom see that KJ since I healed it - I have so many questions answerable only with a scantool, even more with a 'scope, even more with just hands-on - I guess, just like DCX, I shoulda engineered some planned obsolescence into the fixes, so it'd havta come back in every so often - sometimes, it's hell to be good.....................

At the rate things are going, don't be surprised if the LostKJ community pitches together and takes a collection to buy you a CRD development mule.

- Chris

Joe Romas · **Posted:** Mon Jan 14, 2008 7:51 am

Yesterday I used vag-com in it's obdii mode to monitor 4 PID's and see how long it would work before locking up :lol:

20 minutes

But as soon as I started moving I got the ESP/BAS, skidding car symbol and check engine lights on. Then while driving the ABS and Break warning lights would flash every 30 seconds or so. The interface I have is HEX+CAN Serial. So far I've not been able to find controlers using CAN and the scan function in vag-com.

The PID's vag-com gives readings for are:
4, 5, 11, 12, 13, 15, 16 17, 28, 3 and 35.

Hope this helps

Joe

Scangage II Question

Who is online