94 GT cooling fan always on

RockOn · Apr 18, 2019

So here is some data:
- tested sensor in engine at pins and reading is 58k ohms (garage at 50 degrees)
- chart says should be around 56.7k ohms so thinking sensor is ok
- volts to connected with IGN On is 4.65v (I know not 5 but...)

So sensor is or should be showing EEC a “cold” engine.

So is the verdict a shot EEC?

Anything else I can check?

Note/background:

1.) no CCR as this is a project car and have the EEC wire (ground) for Fan Control to a stand alone relay.
I had spent 2-3 days testing circuits, starter system, etc and everything seemed fine - fan did not come on, fuel pump came on for 3-5 sec and then shut off, ABS relays cycled as they should.

2.) Is there a specific parameter in the tune I can check? I have a Tweecer that I just started playing with.

This was after about issue started, I did hook the Tweecer up and used a different known tune and same thing happened - Fan always on.

But there was also a “junk” tune on there as well and:

- fan did not come on
- fuel pump ran continuously

GLK95GT · Apr 19, 2019

Have you removed the tweecer to see if it goes back to normal? If it only happens when connected the port is likely not clean enough.

RockOn · Apr 19, 2019

Yes - when it was connected and on a junk tune, the Fan did not come on but the fuel pump was running constant.
When i disconnected the Tweecer it went back to my original problem - Fan always on but fuel pump acted normal.
I also loaded a known "good" tune and reconnected the Tweecer and then no matter Tweecer tune, Tweecer off, or Tweecer removed and stock tune - same issue.

Going to take the EEC apart and look for burnouts and also check the continuity between the return signal wire to the EEC.

Anything else?
Car is not able to be run to get temp warm as this is all prep for 1st start.

I'm using the 2 speed dual Fan, but not the CCRM.
I have the Low Speed (EEC triggered) and a High Speed (via dash switch) on separate independent relays (car had A/C removed as well).
Maybe the EEC doesn't know how to accommodate for this.
Seems that there is something in the Tweecer tune that I can modify to shut the Fan off / only have it use temp for on/off - not speed, A/C signal, etc.

I can also just also pull the fuse for the Low Speed controlled via EEC and see if the engine otherwise runs and use the dash switch.
But would like to have it right.

RockOn · Apr 21, 2019

Ok, so OBD1 reader came today and I pulled codes:
- 118 (O)Coolant Sensor over max voltage (so this makes sense with Fan always on)
- 565 (O) Purge Solenoid error (this makes sense since I have no smog items)
- 512 (C) PCM Keep Alive

So this can point to what I had planned to change out first (ECT sensor) as #1.
And then if still persists the EEC.
Still have to check +12 to pin1 on connector - if so I think its definitely the ECC going out.

Comments?

RockOn · Apr 28, 2019

So changed the ECT sensor and code changed from 118 (over max volt) to 116 (ECT out of range)

565 still there until I can figure out how to bypass that in the tune/strategy (getting help on EFIdynotuning)
512 is intermittent depending on how many times I hit the batt cut off switch
511 now due to Tweecer/chip being installed

New ECU coming Mon or Tues so will swap that hopefully to get past the ECT issue - will keep updated

RioRed95Cobra · May 13, 2019

Update?

RockOn · May 13, 2019

Yes sorry.
So final remedy to this is that EEC grounds to shut low speed off (not the other way around to ground to turn on).

This makes sense as it’s a safety built is such that the EEC goes bad and fan is auto On to prevent overheating.

Since I’m not using the CCRM, I needed to mimic the controller function with a 2nd relay so when EEC un-grounded this “control” relay, the “power” relay was closed to turn the Fan on.

Verified by IngOn = no Fan
Disconnect ECT sensor = Fan on
Ran Diagnostic with reader = Fan and Fuel relays cycle on/off as they should

I can post wiring diagram if of interest.

RioRed95Cobra · May 13, 2019

RockOn said:
Yes sorry.
So final remedy to this is that EEC grounds to shut low speed off (not the other way around to ground to turn on).

This makes sense as it’s a safety built is such that the EEC goes bad and fan is auto On to prevent overheating.

Since I’m not using the CCRM, I needed to mimic the controller function with a 2nd relay so when EEC un-grounded this “control” relay, the “power” relay was closed to turn the Fan on.

Verified by IngOn = no Fan
Disconnect ECT sensor = Fan on
Ran Diagnostic with reader = Fan and Fuel relays cycle on/off as they should

I can post wiring diagram if of interest.

Interesting. Been fighting this myself. Few weeks ago had it happen.. bought new ccrm.. went away.. other day came back after I loaded a new tune.. now it's back to always on.. both ccrm's and 2 diff computers... lol.

arg

RockOn · May 13, 2019

RioRed95Cobra said:
Interesting. Been fighting this myself. Few weeks ago had it happen.. bought new ccrm.. went away.. other day came back after I loaded a new tune.. now it's back to always on.. both ccrm's and 2 diff computers... lol.

arg

So I did the same and swapped EEC and ECT as I thought that had to be it.

But I was missing how the EEC wiring actually worked. Once I solved that, issue solved. Good news is I have spare EEC and ECT now and both where freebies!

Sorry can’t help as I am not using the CCRM. Are you getting any EEC codes?

RockOn · May 13, 2019

RockOn said:
So I did the same and swapped EEC and ECT as I thought that had to be it.

But I was missing how the EEC wiring actually worked. Once I solved that, issue solved. Good news is I have spare EEC and ECT now and both where freebies!

Sorry can’t help as I am not using the CCRM. Are you getting any EEC codes?

Can you go back to base tune and see if problem goes away? I did have a tune that had the some settings that were wild that resulted with fuel pump in constant run. If you could do this then you eliminate a CCRM or EEC issue.

Have you tried the ECT? Which is why I asked about codes.

RioRed95Cobra · May 14, 2019

RockOn said:
So I did the same and swapped EEC and ECT as I thought that had to be it.

But I was missing how the EEC wiring actually worked. Once I solved that, issue solved. Good news is I have spare EEC and ECT now and both where freebies!

Sorry can’t help as I am not using the CCRM. Are you getting any EEC codes?

No codes

94 GT cooling fan always on

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