Question about 1998 Jeep Grand Cherokee

3 Answers

I get an intermittent "Coolant Sensor Bad" The FSM is clear, Bad mean the line to the coolant bottle switch is open.

I get an intermittent "Coolant Sensor Bad" message on the VIC...the coolant level sensor was changed out as was its connector...how do I make this annoying message stop? Interestingly, it happens less in cold weather... Checked out all other coolant sensors via the OBDII port and all was showing proper function...

Posted by on

3 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    President:

    An expert whose answer got voted for 500 times.

  • Master
  • 1,201 Answers

The coolant sensor and the coolant level sensor are two different sensors. Your message center is showing (coolant sensor bad),not level sensor bad.
The level sensor only monitors the amount of coolant in the container
The coolant sensor senses the degrees of the coolant, which turns on the electric cooling fans. Change the coolant sensor, and the problem should go away.

Posted on Nov 16, 2009

  • 1 more comment 
  • Anonymous Apr 27, 2016

    the error with bad in it , is always the bottle. per fsm pages below, image 1
    bad means the bottle sensor reads 12v
    which means this path is open.
    the line has 2 legit voltages
    0v (empty bottle) (grounded)
    and way less that 12v, my guess 6v.
    12v means open line. can be the sensor switch
    the 2 wires
    are a bad vic.
    a bad vic the voltage at the sensor would be 0v all the time and 12v at the vics processor.
    can be just the pin solder joint cracked,
    we see them all the time.

    vic 12v, resistor >>pin vic >>> switch >>>gnd
    the vic has pull up resistor. inside.
    this resistor i guess is same as in the switch.
    so if the line open the vic sees 12v a "bad".
    if the line switch (normal)is at 3k, we get 6v.?
    if the line switch grounds (0v) the vic sees
    0v. and shows empty bottle.
    im that guy that fixes the brain side..

    i can draw the circuits, ask.

  • Anonymous Apr 27, 2016

    not true, the proof is in the FSM
    the VIC message has only one meaning.
    BAD means:
    THE BOTTLE SWITCH line is cut. in some way
    that includes the VIC display pin for same
    cracked,
    it's a computer input and is pulled up internally to go to high voltage (5v or 12v).
    this high voltage is FAIL detection,
    means no current is flowing and a message
    is displayed as bad.
    if you ground this VIC pin, and it shows bad
    that proves the VIC is bad. fixed many. like it.

  • Anonymous May 13, 2016

    lets be more clear.
    the line open can be ,
    the total , circuit. end to end
    starting at an open ground on switch side
    all the way to the HEAD and then inside the head, it too can have cracked solder pin that goes open so often due to vibration.
    all bad means, to the brain is
    the line is open and draws zero current.
    dead 100% open. or close.
    because im the chap that fixes the brain
    i know all these facts.
    this version is a 3 level analog input to the brain.
    I cut teeth on PLC, and before that we be built them (from scratch) before the world knew what PLC ment. and later the laggard car companies.
    (industry)

×

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Jeep Master
  • 20,706 Answers

Posted by on Nov 16, 2009 !!!!!!!! revived by piggy-backer.
the sensor is in the bottom of the side overfill tank, and is a fload switch (and hidden resistor),
The exact message " coolant bottle low/bad"
in your case it shows the BAD word, (matters)
this means the bottle switch is open
and not 3000 ohms, (normal) nor zero ohms as it must be.


the Cluster brain has 3 level logic.
0 ohms full.
3000 empty
open line BAD , means cut line. open on ground end cut.
or the wire to the Cluster at the pin on the cluster is cracked,(solder crack easy fix )

the cluster forces current down this wire.
if no current flows at all , the line is bad.(open)
dead open, why/where its open the cluster dont know
only that it is. (it actually measures volts there)

the acid test, is ground the cluster pin direct to ground, if BAD word fails to show, the cluster is ok.
if bad Shows, now, the cluster is bad.
easy.

Posted on Apr 25, 2016

  • Anonymous May 10, 2016

    the word "BAD" is the key to why,
    it has only 1 meaning on this car.

×

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Jeep Master
  • 798 Answers

I'm in the UK. I have a 1998 Grand Cherokee. For 2 years I have been getting a 'Coolant level sensor bad' message on the message centre. Two years ago I changed the coolant level sensor which made no difference...

... then I found out that it was a common Jeep fault - an untrue error message. Some things are easily ignored..

Posted on Apr 18, 2016

  • 1 more comment 
  • _-__-___-_
    _-__-___-_ Apr 26, 2016

    2009 posts. ok....
    FSM page, its free to read.
    page 8w-29 and the one page only that shows what the software means by BAD, cluster brain. Bad = open line fail,hard failure.


  • Anonymous May 13, 2016

    so true humans can check levels now for 100 years. zero computers needed to do that..

  • Anonymous May 14, 2016

    if i had a nickle for every head jerked
    re-soldered and fixed, id be retired early, H3LL , i am. vibration is the killler. or...

    Some cars the head PCB soldering job looks like done with no flux. and cold solder joints in the factory, seen lots of Dodges like that. Wave soldering by mad men.
    have endless stories on this...topic....

×

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

2 Answers

"sir overheating problem, fans not on properly and speedy so thats why coolant Stream from bottle"


it gets a high-temperature signal from the coolant temperature sensor,if the sensor is bad. it will not operate right. Current flows through the closed contacts of this switch to the electric motor, which spins to operate the fan. if the coolant level is ok, I would check the coolant temperature sensor and the fan relay in the fuse box. Good-Day!

Jun 12, 2014 | 2009 Chevrolet Optra 1.6

1 Answer

Coolant sensor bad


no it does not.
not ever.
it may run a test on the ECT and tell you it reads wrong, sure.
but that ONLY means the test failed, a technician
then tests it by hand , then the wires.
no ecu can tell you what part on any car is bad, ever.
it ONLY a test.

what does ECT read , in ohms cold 3000 or more? what?
then ECT read hot, 300?
if the ECT reads per the FSM chart then its good.
so the wires are bad.
i'ts that simple..
rare but possible is intermittent ECT the cause.

The PCM checks the ECT 3 ways.
1: open
2: shorted.
3: too slow to rise. (bad engine coolant thermostat , and others) ask

so in case 3 , the ECU is not saying the ECT is bad. it dont know.
it only sees it reads wrong, and never ever knows the why.

Mar 19, 2014 | 1996 Jeep Grand Cherokee

1 Answer

Giving the code E.27


E27 Open Throttle Switch Signal here is a list of all codes E12 No Distributor Reference Signal E13 Oxygen Sensor Not Ready E14 Shorted Coolant Sensor E15 Open Coolant Sensor E16 Generator Voltage Out of Range E19 Shorted Fuel Pump Circuit E20 Open Fuel Pump Circuit E21 Shorted Throttle Position Sensor E22 Open Throttle Position Sensor E23 EST Signal Problem E24 Speed Sensor Circuit Problem E26 Shorted Throttle Switch Circuit E27 Open Throttle Switch Signal E30 ISC RPM Out Of Range E31 Shorted MAP Sensor Signal E32 Open MAP Sensor Signal E34 MAP Sensor Signal Out Of Range E37 Shorted MAT Sensor Signal E38 Open MAT Sensor Signal E39 VCC Engagement Problem E40 Power Steering Pressure Switch Signal E41 Cam Sensor Signal Problem E44 Oxygen Sensor Signal Lean E45 Oxygen Sensor Signal Rich E47 BCM to PCM/ECM Data Problem E48 EGR System Problem E52 PCM/ECM Memory Reset E53 Distributor Signal Interrupt E55 Closed Throttle Angle Out of Range E58 Pass Key Control Problem E60 Cruise - Not In Drive E61 Cruise - Vent Solenoid Problem E62 Cruise - Vacuum Solenoid Problem E63 Cruise - Set Speed vs Vehicle Speed E64 Cruise - Acceleration Too High E65 Cruise - Servo Position Signal Problem E66 Cruise - Engine RPM Too High E67 Cruise - Switch Shorted E68 Cruise - Command Problem E70 Intermittent TPS E71 Intermittent MAP E73 Intermittent Coolant Sensor E74 Intermittent MAT Sensor Signal E75 Intermittent VSS Signal E80 Fuel System Rich E85 Idle Throttle Angle Too High E90 Cruise - VCC Brake Switch Signal Problem E91 Cruise - PRNDL Switch Problem E92 Heated Windshield Request Problem E96 Torque Converter Overstress E97 P/N To D/R Engagement Problem E98 P/N To D/R ISC Engaged Problem E99 Cruise - Servo Apply Problem

Jul 31, 2013 | 1992 Cadillac DeVille

2 Answers

Low coolant light keeps coming on and going off.. months ago i had the intake manifold fixed due to antifreeze leak.. but theres no leak i can see.. some small smell of antifreeze but the light comes and...


Well, top off the overflow tank to the marks as indicated based on engine temperature, and see if it happens again, and note how long it took for it to happen.

Dec 18, 2009 | 2003 Pontiac Grand Am

1 Answer

Changed expansion tank but light still on any ideas 03 ford escape low coolant level light on dash stays lightup


bad low coolant switch or still low on coolant.

Engine Cooling The cooling system components are the:
  • engine coolant temperature sensor (ECT sensor) (12A648)
  • radiator (8005)
  • degas bottle (8A080)
  • radiator draincock (8115)
  • water pump (8501)
  • water temperature indicator sender unit (10884)
  • water thermostat (8575)
  • dual speed fan motor assembly
The water pump circulates the coolant.
The water thermostat:
  • controls the engine coolant temperature.
  • allows quicker engine warm-up.
The degas bottle:
  • provides a location for fill.
  • contains coolant expansion and system pressurization.
  • provides air separation during operation.
  • replenishes the engine coolant to the system.
The fan motor (8C607):
  • operates only when the ignition switch is in the RUN position.
  • will not operate with the switch in the OFF position.
The engine coolant flows:
  • from the lower radiator hose (8286) to the water pump.
  • from the water pump to the engine block and the cylinder heads.
A closed water thermostat returns the engine coolant to the water pump; an open water thermostat allows the engine coolant to flow to the radiator.
Engine coolant provides freeze protection, boil protection, cooling efficiency and corrosion protection to the engine and cooling components. In order to obtain these protections, the engine coolant must be maintained at the correct concentration and fluid level in the degas bottle.
When adding engine coolant, use a 50/50 mixture of clean, drinkable water and engine coolant.
To maintain the integrity of the coolant and the cooling system:

Dec 07, 2009 | 2001 Ford Escape

1 Answer

Temp gauge will peg, 2 minutes after getting to normal operating


I know you dont want to hear this but sounds like you have a bad head gasket or a cracked head,you can check it with a clear bottle unhook your overflow line in put it in the bottle with water in it,if you have bubbles in the bottle you are getting compression in coolant,Hope this help you

Sep 06, 2009 | 2002 Kia Sedona

2 Answers

Check Coolant / STOP lights


It depends on the level of the coolant...
There is likely a float switch if it is checking for the amount of coolant. This would probably be in the overflow container off to the side. If the level is fine but the lights still come on, follow the wires from the coolant sensor back a little bit to see if they have come unplugged from the harness.

Aug 14, 2009 | 2003 Volkswagen Passat

1 Answer

Replacing a 1997 bmw 528i coolant tank. What parts should i purchase besides the tank? Where is the coolant level sensor in this tank? Thanks,


hose clamps, 1/4 hose, and 5/8 hose. Whaddya mean where is the coolant level sensor in the the tank? Look AT the tank, it's a little bit bigger than a small water bottle. Even if they wanted to hide it in there....they couldn't. You look at the filler hole at the top of the small water bottle looking tank----and bingo, there's the sensor. If someone wanted to hide an elephant in your living room, you wouldn't ask where in the living room is the elephant. Is there another question you're asking about the sensor that isn't being clearly communicated?

Jul 10, 2009 | 2008 BMW 528i Sedan

1 Answer

Monte carlo 01 runs hot, says low coolant but its full


Thermostat is probably stuck closed... Run the car with the cap of the bottle or radiator and see if it starts to circulate when it gets hot... Be careful though because it can over heat and have no coolant flowing.. And also watch for spewing fluid if it get hot at the place you took the cap off.... The low coolant could also mean the radiator is not full but the bottle is... Check for a restriction from the bottle to the radiator.. If you see a sensor on the bottle it could be bad... But That won't cause it to over heat. It'll just say low coolant because the switch is stuck.
Also does the fan come on while it's getting hot?
If not that could be the reason for the overheating.. And the coolant level sensor could be bad telling you it's low
Cap off look for circulation of antifreeze.
At the same time before it over heats make sure fan is coming on. No fan on? Fan fuse or relay could be bad... Also maybe a wire.
No circulation? Thermostate stuck or restriction in coolant hose...Line... Radiator..... And worse case scenario the water pump might be bad.
The low level I wouldn't worry about. Find out why it's over heating first.

Apr 22, 2009 | 2001 Chevrolet Monte Carlo

2 Answers

2000 Lincoln Ls Heater blowing cool air


You also could have air in your coolant system. You can't just add coolant on these models after you drain the system or let it run low on coolant. The degas bottles on these models also have a flaw, where they crack along a seam. Sometimes coolant will leak, sometimes not, depending on how high the crack is on the bottle. But what it is guaranteed to do is allow air into your system, which can cause havoc with overheating (air surrounds the thermostat so it doesn't open) and keep coolant from flowing, particularly through the highest point in the system: the heater core. There is a heater core bleeder valve attached to a line near the top of the degas bottle (next to the expension line up top) with a plastic, flathead srewdriver face. Turn the heat on high and run the system at idle for 5 minutes. Then open the valve and keep it open until a steady stream of coolant comes out. (It's like bleeding your brakes.) That will clear any air from the system and at least give you peace of mind that this is not your problem. Then run the motor at 2000 rpms, with the heat still on high, for about 5 minutes or until hot air starts coming out. Release the bleeder valve again until a steady stream comes out. Then let the system cool and check your coolant level and fill as needed. I'd pull the degas bottle and inspect it...should have been a recall.

Dec 13, 2008 | 2000 Lincoln LS

Not finding what you are looking for?
1998 Jeep Grand Cherokee Logo

608 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts

yadayada
yadayada

Level 3 Expert

75077 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22095 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

7768 Answers

Are you a Jeep Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...