95 Corvette 16181333 ECM Fan control

[dave w]

The TunerCats fan control screen shot, from the above .bin.

dave w

[Oysteinbno]

I've wired the relay the way you described it. But it didn't help in any way.
Then I programmed the ECU with the 95 Corvette LT1 4L60E 1008.bin‎. Did some changes in the bin. I don't want all the MALF codes because of the EGR, and air pump
When I started up after reprogramming, the fan started right up again. Got an MALF 43, and made the changes to the bin to remove this. Reprogrammed the ECU and the fan did not start and instead I got the Fan MALF again.
Is there a known problem about reprogramming the ECU within 10 minutes or?

Oystein B

[dave w]

I'm thinking the green and dark blue wires are sending ground to the fan relays as soon as the ignition switch is turned on. I just don't know why.dave w

[Oysteinbno]

No it doesn't send ground until the engine starts.. I'l try to reprogram the ECU once more, and see what happends.

[EagleMark]

The TunerCats fan control screen shot, from the above .bin.

dave w

Now I see why you were referring to Fan Controls by Oil Temp! Just looked at TunerPro definition and it to says Oil Temp. I'd swear they are wrong and this is based on coolant Temp not Oil Temp... Oil temp would never get that hot before engine overheats at say cold start and AC on? Just does not make sense to be based off Oil Temp for Coolant temp fans?

I've wired the relay the way you described it. But it didn't help in any way.
Then I programmed the ECU with the 95 Corvette LT1 4L60E 1008.bin‎. Did some changes in the bin. I don't want all the MALF codes because of the EGR, and air pump
When I started up after reprogramming, the fan started right up again. Got an MALF 43, and made the changes to the bin to remove this. Reprogrammed the ECU and the fan did not start and instead I got the Fan MALF again.
Is there a known problem about reprogramming the ECU within 10 minutes or?

Oystein B

No. There is a slight delay of PCM powering off at Key Off but it's only a few seconds.

BUT! Error Code 43 is a known issue and not something that should be turned off unless your not running a knock sensor. Code 43 puts these PCM in limp home mode and answers why your fans are on. Fans come on during Limp Home Mode in these PCMs. We've been through this before. Turning off the error code does not disable any circuit. It just turns off the error code. EGR, Air and Knock have to be disabled by changing Enable parameters.

You never answered what Check Engine Light was doing? IIRC in a data log with TunerPro ADX file it will tell if PCM is operating in LHM.

[Oysteinbno]

Check engine light goes on when I turn on ignition. When I start, the light goes off. and after a little while it comes on again.
When I use Datamaster to log, the following MALF is red:
code 26, 27, 29, 43
And datamaster show that there is knock count from the knock sensor.
Is my ECU fuc...t up??

[EagleMark]

There is a real possibility you have a faulty PCM!

Error 26 "26 ECM detected the wrong potential voltage at the #1 quad-driver module circuit for 20 seconds." I beleive is for Air. Disable Air by setting enable temp to not come on.

Error 27 "27 ECM detected the wrong potential voltage at the #2 quad-driver module circuit for 3 seconds." I beleive is for EGR. disable EGR by enable temp to not come on.

Error 29 "29 Secondary air injection pump circuit voltage was wrong for 26 seconds." Again disable air.

Error 43... have to diagnose knock circuit. Disabling "Knock Retard Enable Coolant Temp. " to not come on may help for now.

[Oysteinbno]

I'm starting to wonder if the wiring I bought is no good.
I drove the Corvette before I took the engine from it, and the only problem I had then were one faulty O2 sensor.
I made the changes described above, and reprogrammed the ECU. Now I only have MALF 43, and 97 from datamaster. When I use TunerPro RT I got one MALF more, #76.
And the fan still start when the engine start.
Is there any difference between 16181333 and the16188051 ?

And I'm realy gratefull for the help I'm recieving here.

Oystein B

[EagleMark]

Error 97 is from VSS I beleive... Error 76 is voltage high. Is voltage high? Remove power or clear codes in PCM.

94 and 95 PCMs do have wiring differences do to auto tranny PWM TCC in trans change. Your bin has error 83 enabled so I'm guessing it is a 95 and OK. I've swapped the 2 PCM numbers in manual trans and beleive they are the same?

We chased a error code 43 once and never did find it or it was not reported back. New and tested knock sensors (2 on caprice) wiring ohmed, PCM replaced as well as knock module..
http://www.gearhead-efi.com/Fuel-Inj...3-in-my-95-LT1

Are the knock counts your getting correct? Or just constant?

[Oysteinbno]

If I look at two different log files from DataMaster, the knock count is not the same, so it's not constant.
The engine is from a 96 corvette with 4L60E transmission.
The alternator is charging at 14,7 on idle speed.

[dave w]

I'm flying today, so I'm limited on what I can help with.dave w

[Oysteinbno]

Probably a stupid question , but how can I see if the ECU is in limp home mode?

[EagleMark]

Check Engine Light on.

In TunerPro ADX file is Code 43a,c and d any of these will cause LHM.

Also BLM will be locked at 128.

[Oysteinbno]

Check Engine Light on.

In TunerPro ADX file is Code 43a,c and d any of these will cause LHM.

Also BLM will be locked at 128.

Ok. I've tested some more.. I've meassured the Knock sensor. It's 3903 Ohm from sensor to ground. The voltage is at the cable 4.97 volts. When I start the engine, the Check Engine light comes on and the fan starts. BLM is locked at 128.
If I use a hammer and knock the engine block the knock counter increases...
I have absolute no clue what'swrong here...
I have atached a log file.

[EagleMark]

Pretty easy first issue! Right O2 sensor not ready = Open Loop.

Still have error 76 voltage high long term? You had 14.7 at idle which is a little high for idle but OK. Does it go up after that? Clear codes...

Does the VSS work? I think the error 97 is this issue, now it may be a tranny difference from 1996 trans to 1995 PCM?

Your getting some knock counts\ even with the error 43, now I wonder if this could be a 1 or 2 knock sensor issue? The Caprice LT1 has 2 knock sensors and F or Y body only has 1... I think? I've never looked into what differences this has made in PCM or knock module? Just from memroy it's all the same?