02' Grand Caravan Sport 3.3L Coolant Sensor Issue - DodgeTalk : Dodge Car Forums, Dodge Truck Forums and Ram Forums
Notices

Reply
 
Thread Tools
post #1 of 3 Old 03-05-2019, 12:22 PM Thread Starter
SVEN44
Registered User
 
Join Date: Mar 2019
Location: Tucson
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
(Thread Starter)
02' Grand Caravan Sport 3.3L Coolant Sensor Issue

I posted in the new members area, but I thought that posting here might be more helpful.
I am having a cooling fan issue. They don't come on unless the A/C is on, or the coolant temp wire is unplugged.
So I checked the voltage to the sensor, K/O E/O, No Key, and Running.
K/O E/O- 12.3V at the blue wire. 7.7ishV at the red wire (which I think can't be good)
No Key- 12.3 volts at the blue wire(which can't be good, but I triple checked this). 0v at the red wire.
Running- 14.4V at the blue wire. and 11.3ishV at the red wire.

Also I checked all of these with the wire disconnected from the sensor as well and the readings were similar, but only with the engine off and key on, or no key.

I am sure there is something wrong with this. Strangely enough the gauge is just going up like any old normal gauge, it never shows hot, stays right around 1/8 below the halfway point. I am thinking there is a wiring issue, but I wasn't sure about the PCM grounding, because the fans come on with the connector unplugged. And I am having a heck of a time finding online wiring diagrams for this model and year. I am wondering if I should just cut the wiring at the sensor and the PCM and see if the fans work right. I am not sure about a bad ground, because I think the PCM grounds these fans, and they are coming on with the connector to the sensor being unplugged and the A/C being turned on.

If anyone has access to a wiring diagram that would be helpful. Or If I am missing a ground somewhere that would cause this.
Thanks SVEN
SVEN44 is offline  
Quote Quick Reply
Sponsored Links
Advertisement
 
post #2 of 3 Old 03-07-2019, 04:13 PM Thread Starter
SVEN44
Registered User
 
Join Date: Mar 2019
Location: Tucson
Posts: 4
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
(Thread Starter)
Update
I pulled the message center off and found someone had jumpered the check engine light.
P0118 is on and won't clear.
Which is coolant temp high input.

I checked the wiring at the sensor. It's good now. 5volts reference and ground.
I checked the reference at the PCM, and it is reading, 5volts with it unplugged, and then whatever the sensor is reading when I plug it back in.
I also checked resistance of the wiring to the PCM to make sure it is good, it's fine.
Does this mean that the PCM is bad?
I just want to be sure before spending a huge chunk of money on it. Or is there something else I should check?

Also is there some reason the gauge is reading with the sensor unplugged?
SVEN44 is offline  
post #3 of 3 Old 03-12-2019, 11:05 PM
guyonearth
Registered User
 
Join Date: Nov 2009
Posts: 148
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 17 Post(s)
Quote:
Originally Posted by SVEN44 View Post
Update
I pulled the message center off and found someone had jumpered the check engine light.
P0118 is on and won't clear.
Which is coolant temp high input.

I checked the wiring at the sensor. It's good now. 5volts reference and ground.
I checked the reference at the PCM, and it is reading, 5volts with it unplugged, and then whatever the sensor is reading when I plug it back in.
I also checked resistance of the wiring to the PCM to make sure it is good, it's fine.
Does this mean that the PCM is bad?
I just want to be sure before spending a huge chunk of money on it. Or is there something else I should check?

Also is there some reason the gauge is reading with the sensor unplugged?
A code P0118 may mean that one or more of the following has happened:
A bad connection at the sensor
An open in the ground circuit between the ECT sensor and the PCM
A short in the voltage feed between the sensor and the PCM
A bad PCM (less likely)
A bad temperature sensor (shorted internally)

Do not buy a PCM as your first step. You need to do some troubleshooting first. Step one, get a new temperature sensor. Step two, check your wiring for shorts, back to the PCM. If you had an anomalous high voltage reading before, but now it's normal, there may be an intermittent short. A wiring short is the most probably explanation...assuming somebody hasn't messed up the wiring somehow, I've seen people do all sorts of stupid things.

Last edited by guyonearth; 03-12-2019 at 11:10 PM.
guyonearth is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to use most of our features, you must first register.
Please enter your desired User Name, your Email Address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
The registration process requires you to activate your membership by following a link in an E-Mail that will be sent to you immediately upon completing this form. You must enter a valid email address or you will not receive this activation code and you will NOT be registered. Your E-Mail address is NOT publicly available to anyone as policy.

AOL E-MAIL USERS: Please click HERE for important info pertaining to your e-mail address.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Code list slingin_mudd 3G Dodge RAM - General Talk 0 08-27-2017 08:39 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

 
For the best viewing experience please update your browser to Google Chrome