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99 Chrysler Town & Country: overheated..jumper..work fine..12 volts

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My radiator fans stopped working on my '99 Chrysler Town & Country, and the car overheated. A jumper to the fans showed that they work fine when 12 volts gets to them. The minivan drove fine. I wasn't getting any voltage from the "relay control in" on the radiator fan relay. THere was voltage coming out of engine coolant tamperature sensor, and that was reaching the PCM. No voltage was coming out of the PCM to go to the relay, and the wire from the PCM to the relay is fine. So, I needed to get moving, so I unplugged the relay, and hooked up a switch to manually turn on the fan. The fans worked. But when I started driving again, the car went into limp in mode, and wouldn't go into high gear. At the same time, the service engine light came on. I took the car to Autozone and they hooked up the OBD-II and found the following codes: P1767, P1491 (this one deals with the relay), P0700, P0700PD. Three of these deal with the transmission. I have not had any problem with the transmission.
Do you have a wiring diagram for your vehicle?I don't but the reason I ask is most pcm controlled relays are controlled on the ground side.What that means is you shouldn't be looking for voltage you should be checking to see if the pcm is grounding the relay to turn the fan/fans on.I would fix the coolant fan problem before I tried repairing any transmission codes.Transmissions are heat sensitive,if they get hot from an inoperative cooling system fan they could set transmission codes.If the condition continues without being repaired you may end up with a transmission overhaul as well.Most modern transmissions go into limp home mode during an electrical or repeat mechanical failure detected by the computer.
Customer: replied 11 years ago.
Reply to Davo/diablo666's Post: I hear what you are saying about solving the fan problem first and how that leads to the transmission codes. I do have the wiring diagram. The relay has four wires: 1) BATTERY, an always-on 12v separately fused wire, 2) RLY CONT IN, that comes out of the PCM, 3) FAN OUT, that goes to the fan, and 4) GROUND, that appears to be always grounded to the chassis and is always connected to the ground side of the fan motors.

Does that help you figure about the grounding?
Customer: replied 11 years ago.
About the ground wire coming from the relay, I'm not sure it's always grounded, but it appears to be in the diagram.
What I would do is jumper the relay control wire to ground with a fused jumper wire(10 amps) and see if the fans come on.This will tell you if the relay is good.I found a diagram but its rather weak it only shows me 3 wires. From what I see I can't be sure if the relay is power or ground controlling the relay but most relays are ground controlled.You could try the above test with battery voltage if the fans don't come on with the wire grounded just make sure the pcm is disconnected prior to testing.Let me know what you find.
Customer: replied 11 years ago.
I tried the jumper and the fan does not come on.
When are you available???
If you jumpered the relay control wire and you have power and ground at the relay the relay is bad.
Customer: replied 11 years ago.
Note that I jumpered the ground only. Just to be sure I understand what you are saying, although I have power to the relay, and the relay is grounded, and there is no voltage going from the PCM to the control wire of the relay, the relay can still work? I bought a relay, but don't want to take it out of the sealed package if there is no voltage to allow it to work. I did read your earlier notes, but understood that it was assuming no ground to the relay. Please clarify for me. Thanks.
What I wanted you to do is ground the pcm control wire not the ground wire.When the pcm sees the need for the cooling fan to be on it grounds the control wire to turn the fan on.So try grounding the pcm control wire.Take a fused jumper from the control wire to the negative side of the battery and see if the fan kicks in.The wire should be light green/dark blue according to my diagram.The fans should run when you do that if they don't the relay or wiring to it is bad.
Customer: replied 11 years ago.
I got that wrong, sorry. I'll have to try that first thing in the morning. Roughly when are you available tomorrow?
I will make a point to be here from 12 to 2 pm est.
Customer: replied 11 years ago.
I grounded the right wire and the fan came on. So I put in the new fan relay and the fan works. I went to Autozone to reset the codes. I did this, and the code for the relay went away. One code for the transmission went away. Where there used to be both a P0700 and P0700pd, now there is only the P0700pd. I don't know what the "pd" means. One other code remains: P1767pd. Now I know that P1767 was a code before, but I'm not sure if the "pd" was on the end. I did this testing by starting the engine, after erasing the codes, stopping it, and reading codes again. I did not actually move the car before reading codes again. Of course, I'm still stuck in limp in mode.
Customer: replied 11 years ago.
Apparently, the "pd" means "pending". It has something to do with how many times the computer has detected a problem. Maybe I need to start and stop the car some number of times?
It means you have a problem with the torque convertor clutch circuit.My suggestion at this time would be to disconnect your battery and hold the cables together.This will clear all pcm memory and reset the shift adapts to zero.You only need to hold them together for about 30 seconds.Let me know if that takes you out of limp mode.
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Customer: replied 11 years ago.
You're a genius! Everything works fine, and service engine light is off. By the way, I only put my question in a second time when I did not hear from you all day Saturday. You were very helpful, but one difficulty with the Just Answer system is that I don't know when someone is available, and don't know what to do on a Saturday when I want to work on the car and mty help isn't available. I'd like to remove my second statement of the question so that it shows that I have 2 accepts and 2 questions.
Anyway, I sent the $$ for you, and thank you again.
I can't change the 2 accepts 3 questions thing for you no one can.I wouldn't be concerned about it because none of the specialists will hold that against you.If you had 3 questions and zero accepts that could be a problem.Any specialist will know why that 1 question didn't have an accept Trust me on that.As for the saturday thing I work some saturdays and answer questions as soon as I get home.If you need a question answered quicker and more thoroughly all at one time let me know by asking for me and I will do everything possible to comply.I'm also glad I could help you please tell your freinds about Just Answer and of course davo/diablo666.

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