2002 3.3 Caravan "safe" mode.

[AndrewG]

Today was the first I heard this term. Here's the story:

Drove home and parked last night with no issue. This morning battery was dead. Jumped it and left to go buy a battery on my way to work.... Only to find check engine light one and vehicle seeming to only have 2nd gear. Have literally never had a problem with this van. Has a tranny cooler. Level was good, smelled fine, right color all of that. Stop at Advance Auto figuring to get the codes read. Turn the key to shut it of and nothing happens. The van keeps on running with ignition in the off position and the key removed. Gauges and dash lights all shut off, and if you put the key back in and turn it, everything runs its posts like they're supposed to. Pulled the fuel pump relay to shut it down. Guy from AA come out with reader. All transmission codes. Didn't even bother to note them because I can't see how a tranny that has given no sign can just fail like that. Tried disconnecting the battery for a few, with no change. This is a total mystery to me. I have never even HEARD of safe or limp mode until today (first the AA guy, and then reading in here.)
Thanks in advance everyone!

[RIP]

First did you install a new battery or charge the old one? The computers on these vans are sensitive to low or erratic voltages. Get the battery cleared up then see what you've got. If that's done, power from the ignition switch start/run position goes to the IPM then back out to a splice. From the splice it goes to the PCM, EGR solenoid and LDP pump. The easiest to get to is the EGR solenoid. If you have 12vdc at pin 2 (pink/grey wire) on the solenoid connector with the ign switch off, the switch is bad. Could be why your battery drained.

Engines, transmissions, really any component can and do frequently fail without any warning. Most have no idea what "limp mode" is until they're in it. Welcome to the club - unfortunately. Limp mode gives you 1st, 2nd, and reverse gears.

[AndrewG]

Thanks. I will do that this evening. I did not replace it. I charged the old one and left with the intent of getting another one.

[autoservice2013]

Seems to look really a mystery.. i got to try it!

[AndrewG]

UPDATE:
Wow, it's been over a month already? Here's what has happened in that month. I stupidly assumed the ECU was the culprit and replaced it and the battery. When that didn't fix it I put it in the shop (a level above shade tree, but they're cheap and know more than I do lol.) They tell me the transmission shutdown safety relay had fried closed and in turn cooked the TCM (transmission cntrl mod). Took it and replaced TCM and the relay. Still no dice. Check engine light on, stuck in 2nd. I figure OK, there's really only one component left in this system... The shift solenoid. Sooooo, I replace that. STILL not working. Put it back in the shop and NOW they say the power distribution center (fuse box under hood) is the problem. They insist it's not a bad wire. So I ordered one from ebay for 50$. I can't wait to see what they say if that doesn't fix it...

[hundahunta]

what codes are you getting

[AndrewG]

Originally Posted by hundahunta

what codes are you getting

I'll let you know tomorrow when i put it on.

[DeltaP]

Sometimes cheapest isn't the best call.

[AndrewG]

Yeah, but sometimes it's all we can do. In 25 years of driving, this is the first time I've had to put my car in the shop. Normally you guys, my friend Google and I figure it out and I move on. If when I put the distribution center on it tomorrow it throws a code (as I fully expect it will) I will post it here. If no one has anything on it, it's going in to the next level up of shop. Thanks for all the input so far guys!

[AndrewG]

So I just put the power distribution center on. And it shifted. The first time it did though, the CE light cam on. Code P0700. Erased the code. Going for another ride now. The solenoid I put on (that the shop reinstalled to fix the leak it had) it still leaking. Sigh. But if the rest of it is fixed I'm ok with futzing around with that.

[AndrewG]

Ok. Second ride was a few (maybe 5) miles. Light stayed off until the end. It's shifts horribly, like it can't decide if it wants to shift down or up, then decides to go up with a big lurch. I know I read something about the tranny having to relearn your driving habits. Hard to believe it's default setting could be that bad though. When the light came back on it threw 2 codes: P1768 & P1782. Going to try and fix the leak now. I can drive it this way so at least I can keep playing with it. I didn't want to continue driving it in limp mode.

[hundahunta]

p1768 relay output always off. maybe you have a wiring issue

[AndrewG]

Driven about 100 miles so far. No CE light or oddness. So I guess that was it. Thanks so much everyone.

[AndrewG]

SIGH! Update: Light came back on. P0117 coolant sensor or some such. Tried to change the sensor under the coil pack and promptly snapped the sensor off. Put it in the shop, they replaced the sensor, light still on. Same code. Shop says no power at sensor as there should be. Diagnosed as bad ECU. Florida sends me a new one (had replaced it when all of this started) no dice same code. Bad harness? Everything I've read about it up till this posting says fuel rail harness. How bad is THAT to change lol? And I guess the sensor wiring just happens to be in the harness for the fuel rail?

[jamesslcx]

Sound like you have had a rough time. Try disconnecting the negative cable for ten seconds and drive it again. Sometimes it helps.