19th Oct 2010, 20:52

My 2003 Cherokee has had some of the same problems.

Crankshaft position sensor at 48k, overheat fan relay at 75k. Now it's doing it again at 83K, ECU and a bunch of circuits replaced at dealership.

You know it really makes me angry when I read all these threads about the exact same problems I have had with my Cherokee. It's obvious Jeep knows and refuses to repair or recall this stuff. I have to work damn hard for my money and it is a waste and an expense having such an unreliable vehicle.

They are just too happy to take your money at the dealership and don't really care if the problem was actually fixed or not.

21st May 2011, 11:26

It has been several years since you posted on this site. Don't know if you still have your Jeep, but I am having the exact same issue with my A/C, and I was wondering if replacing the relay fixed your issue. I just don't have tons of money to replace the entire A/C. I can get the relay at Autozone for $10... much better than several hundred or thousand dollars. Fingers crossed.


25th Sep 2011, 21:23

The fan relay is mounted on the fender with 2 sheet metal screws, behind the passenger side headlight/turn signal assembly. Open the hood, remove the long hex head retaining screw in the top of the headlight lens housing. Grab the headlight housing and pull forward until it releases. Once the headlight housing is out, look for a black square housing mounted on a metal backing plate, mounted on the fender with 2 sheet metal screws and with a 4 wire connector plugged into it. The connector has a slide locking tab that must be moved to allow the connector to unplug. Once unplugged, check the condition of the terminals and wires to see if they can be reused or need replacement.

When replacing the relay, I suggest the use of heat sink grease (available from Radio Shack) and the replacement of the zinc/steel screws with slightly larger stainless sheet metal screws (the original screws rust, reducing the relay hold down torque.

1st Nov 2011, 13:58

Hey there, I have a 2003 Jeep Grand Cherokee Laredo 4WD/4.0L. I have come across a lot of blogs saying that the cooling fan relay switch needed to be replaced. My engine has risen to the upper end of the gauge, setting off the check gauges light twice in the past two days. It seems to have only happened when on idle. I would like to diagnose the cooling fan relay first before repairing. Any suggestions?

In your blog you put "there is a cheap do it yourself way to do this." Any chance you could please inform me of this way? Would be very much appreciated. My email is jjthoma2011@gmail.com Thank you.

31st Dec 2011, 08:44

Did you ever solve this check engine light problem? I am having the same problem, but have already tried many things.

28th Apr 2012, 11:26

Good luck with your Toyota, you will need it.

I bought one new in 1991. I had nothing but problems with it. After about six months I called it my TOILET-OTA. The problem was that Toyota would NOT stand behind it.

In 2 & 1/2 years I sold it with less than 11,000 miles on it.

I then bought a 93 Jeep, and now own a Jeep Grand Cherokee Limited. I will NOT buy a Toilet-ota any more. Now I'm happy.

11th Jul 2012, 17:58

I am also the owner of a 2003 Jeep, and today as I was coming home, my relay fan broke AGAIN. I have had to replace the fan every year since I purchased it from the dealer 6 years ago. I am going on vacation tomorrow, and I am not happy. I have also had problems with both driver and passenger windows, tires, heated seats, brakes and a number of other issues that others have complained about.

I hope the Jeep people are reading all of these comments and trying to do a better job.

28th Jan 2013, 21:18

I have the same problem with my 2003 Jeep. Did you ever find out what the problem was?

30th Jan 2013, 01:28

I have an 02 Grand Cherokee that has had multiple vacuum leaks, and instead of putting a new 6" hose on, they would shorten the old hose. I purchased a piece of hose and a clamp, and it never happened again.

Also had the fan relay replaced twice. The second time I did it myself for $46, and it took 10 minutes.

2nd Dec 2014, 03:59

I have a 2003 GJL. I had the same problem with the fan not shutting off, so until I was able to get it to the shop the next day, I disconnected the battery to save it.

The sensor chip went, which is located behind the right light. It was a long job.

Right now I am dealing with a squealing sound on right side that just came on, and I'm not too sure what it is, and way too many times I have coolant issues; pressure builds up and the hose comes off. Regulators and window motors are another issue.

I hope this helps. Thank you.

27th May 2015, 18:58

How are you getting 12 city? And 16 highway? I have the 4.7 V8 and get 15 city and 19 highway. You might have a problem with the intake or exhaust, which would affect fuel economy.

5th Sep 2017, 02:57

Crank case positioning sensor; replace it, don't go to a dealer, go to a regular shop.

5th Sep 2017, 03:00

It's the crankcase positioning sensor for sure or camshaft positioning sensor for sure; don't go to the dealer, go to a regular mechanic, it's an easy fix.

5th Sep 2017, 03:12

Replace the crank case positioning sensor and/or camshaft positioning sensor; a very common problem this will fix it guaranteed. Been there, done that.