98 Coupe. Low Coolant comes on DIC when starting and every few min.
Replaced sensor, no dice.
Unplugged sensor and put jumper on wires. No dice.
Must be a broken wire somewhere. Any idea where that circuit wires to?

 

Can someone please look up the low coolant sensor circuit on for 1998 and tell me where the wires go to?
Thanks!

 

When the coolant level is full it provides a ground to the IPC...when the coolant is low or the ground is lost (your problem) the coolant light comes on. one wire should be 12 volts and the other ground.... you might be missing the ground !!...I don't have the wiring in front of me for a '98 but the 12 volts most likely comes from the IPC I'd say !!....check for a ground !!...I think there is a TSB for this !!

 

I have reviewed my Tech Docs for this system on the 97, 98 and 99 and the Tech Docs are very poor in information and no dedicated wire schematics for the Low Coolant indication system.

NOTE the below is only applicable to a 1998 model year car as the 1997 and 1999 model years have differences in electrical connector pin number locations

Provided that your car is bone stock with NO added electrical items, I have found enough info to get you real close to finding the broken wire and I suspect you may find the wire broken in the area from the surge tank to the under hood electrical center.

Coolant Sensor Description

The coolant level sensor monitors the coolant level in the cooling system and indicates if the coolant is low. This sensor is a magnetic switch inside the surge tank. The magnet (which floats on top of the coolant) closes the switch when the coolant is at the "Full Cold" coolant level. The location of the switch is on the lower right hand side of the tank, at the rear.

If the "Low Coolant" indicator appears, inspect the coolant level.

Important: The vehicle must be level during an evaluation.

If the vehicle is in a nose down attitude, "Low Coolant" could be indicated at a normal coolant level.

Disconnecting the switch opens the circuit and lights the "Low Coolant" indicator

As your reported problem, I agree and believe you have a broken wire or broken jumper in the under hood electrical center....

Before proceeding with the below testing DISCONNECT YOU BATTERY!!!!!

1. Disconnect the under hood electrical center connector C3 and C2.

2. Coolant level indicator switch connector still connected (or jumper wire installed between pins).

3. Connect a DMM between terminal D9 of the under hood electrical center connector C3 and ground.

4. Measure CKT 68 for continuity to ground.

Is CKT 68 continuous to ground?.

1. Disconnect the instrument cluster connector and place jumper to ground from terminal A8 of the instrument cluster connector

2. Underhood electrical center connector C2 still disconnected.

3. Connect a DMM between terminal F7 of the underhood electrical center connector C2 and ground. 4. Measure CKT 68 for continuity to groundIs Is CKT 68 continuous to ground

Locate and repair open in CKT 68 between terminal F7 of the underhood electrical center connector C2 and terminal A8 of the instrument cluster connector.

Is the repair complete


[img]file:///C:\Users\Kevin\AppData\Local\Temp\msohtm lclip1\01\clip_image002.jpg[/img]
Post up your findings,

Cheers,

Goose

 

Thank YOU!
I do have 98 and thanks for much for the info. I am going to work in this ASAP and I will report back.
Probably wont get to it until the weekend.

 

UPDATE> Simplified testing.

Focus area> as a first step in a visual inspection, the wire harness is heavily strained at the coolant level switch connector/plug (due to the 90 degree turn of the wires at the plug) I would focus my attention at the wires in the plug to determine if you have a broken wire at the electrical pin inside the plug.

Before disassembling the under hood electrical center, recommend the follow test to determine if the signal wire (yellow/black wire) is serviceable from the coolant level switch plug through the under hood electrical center to the instrument panel.

Place jumper wire on coolant level switch connector/plug on pin (A) and chassis ground. Power car up and see if the “Low Coolant” message extinguishes. If the “Low Coolant” message extinguishes, this confirms the wire run is serviceable from the coolant level switch plug through the under hood electrical center to the instrument panel.

Post up results of this test.

Turn power off of car.

Place DMM wire on coolant level switch connector/plug on pin (B) and chassis ground, perform continuity check using DMM to determine if the “ Ground” wiring is serviceable from the coolant level switch connector/plug to the chassis ground point (G102)

Post up results.
Cheers,
Goose

 

So much thanks. This is exactly what I was looking for after reading 8090000893344 low coolant threads.

 

Yep the ground wire was bad. Also the sensor is bad. Ran a new ground and jumpered it for now.
Thanks for the help!