1997 Grand Cherokee - coolant temp sensor error (did not post code - vehicle display told me), changed CTS & monitored running temp with scan tool. Temp maxed out at 208f (normal for this vehicle) after 1/2 hr of idling/driving but temp guage still maxed out & check gauges lite is still flashing - also getting 3 short beep error msg that wasn't there before the problem started.

SOURCE: Normal coolant temp for 2003 Jeep Grand Cherokee city/highway V6

Your Jeep should have a 192 or 195 degree thermostat. Do u have to add coolant once in a while? If there is no coolant loss, no overheating problem, u shouldn't have to worry about it, it could be the temp. sending unit is not accurate. If it concerns u it would probably be worth it to remove the thermostat, check the temp rating on it(it should be stamped on it). Replace w/ a new one, and see what it indicates for temp then. Good luck, let me know what u find Curt

SOURCE: no/low oil pressure, high engine temp

I think you have a bad ground on your engine gages...but, more importantly, have your oil pressure checked by a mechanic.  If it is indeed only 20 pounds the engine is sadly on it's last legs.
When you receive advice from this website you have to understand that without the item in front of us, we are only able to provide "a best guess" as to what the problem might be based on you description of the defect.  If you haven't described a clear and precise description of the defect you decrease the chances of an accurate reply.  Thank you.   

ZJ Limited

• 17989 Answers
• Posted on Sep 07, 2009

SOURCE: where to replace coolant temp sensor for 1998 grand jeep cherokee

Check this image...



...in the Section ZJ-Secc-8D-Ignition-Systems (page 5, fig. 10 and 11).

Good luck.

SOURCE: 1996 Jeep Grand Cherokee No Start

I would be thinking that there is a good chance that you need to be checking out replacing the computer, if you aren't getting any communication with the proper scan tool then the computer isn't communicating with anything in the vehicle...... I would have guessed first off that the ignition control module might be bad but that is obviously part of the computer also, I would be looking in that direction.

SOURCE: 1996 jeep grand cherokee limited. engine is

You should have someone sing a dual trace lab scope, look at the Crank Angle Sensor (CKP) and Cam Angle Sensor (CMP) signals to check quality and sync.

Loose timing chains or broken flex plates can change the sync signal to the Powertrain Control Module (PCM) and cause a stall situation. Also you should have someone load test the battery and check the cables for corrosion. If the battery drops excessively during startup, the idle motor stepper count can be lost, Powertrain Control Module (PCM) will relearn it while driving.

Clean the throttle blades and adjust minimum idle.

With the air cleaner assembly off, hold the throttle wide open and look down the throttle with a flash light. Look at the lower intake plenum gasket for leaks, oil will build up around the edges and in the corners.

Perform distributor sync adjustment. I hope this helps. tried my best.....