1st Gen Haltech ECU Discussion

For those embarking on the IC-7 train... I'll have more information soon, it has one large snafu that comes baked in and we will need to talk about. If you have a manual trans and no factory cruise control then you have nothing to worry about though, install is otherwise straight forward.

Here is one nugget of information that you won't have to gather yourself since we figured it out yesterday, the calibration for the fuel level sender.

 

I have learned some things today, not all of them are fun things to learn after cutting up a stock cluster harness to install an IC-7. The factory gauge cluster (after model year 97) does a lot more than most would think even on the later years of Tacomas. Hell really even to this day they seem to, they almost always generate the SP1 signal that's fed to the computers and modules. The cluster provides some form of signal forming, what I believe to be a small buffer and average of the sensor signal so it doesn't bounce around. Well if you have an automatic transmission this can cause the cruise control to inhibit torque converter lockup with the speed sensor bypassing the gauge cluster's smoothing circuit. To allow the drivetrain speed signal to pass from the sensor on the tailshaft or transfercase to the ECU it must go through the cluster or have the input and output bridged without the cluster present. Beyond that the cluster also provides sensor ground to the speed sensor so even if you bypass the cluster you need to find the sensor ground wire in the harness and provide it a path to body ground as well.

Really this information is only necessary to those with cruise control and an automatic transmission. If you have a manual trans and cruise it won't be a concern since the cruise functions to hold speed just fine with the dirty speed signal it's only on an auto that it inhibits the converter lockup and in some cases overdrive because it perceives the rapidly changing signal as a rapid accel or decel which traditionally you'd need to unlock or drop a gear for. So I am currently exploring options to provide a slightly deadened speed signal (a couple milliseconds of buffer would do) or perhaps to just cut the communication between the CC computer and trans portion of the ECU. Issue with cutting the communication to the auto trans control is that CC cancels if it falls behind by 12mph and I'm afraid on an auto trans tacoma it may do that before the auto downshifts or comes out of lockup naturally from it pulling the throttle.

 

Wizardry. Manual trans ftw.

 

Absolutely amazing.

 

Figured a pic was necessary

 

How do you plan to deaden the speed signal for the ECU?

 

Also curious about the dimming levels of the IC7. In my head, having a large LCD screen in your face might be sort of fatiguing during long drives at night.

 

For those waiting for the UC-10, the dash is available for purchase of you reach out to Makomotorsport directly.

 

The ECU doesn't care, the haltech is more than capable of parsing a dirty signal and you can apply a filter scale in NSP.

 

It dims really nicely, you can preset how much when you turn on the lights but it also has an ambient light sensor you can use to fine tune the brightness or let it operate withing a rang of self dimming beyond your commanded dim amt.

 

Installed the Haltech CAN Gauge. It's a pricey little unit but I've been very happy with it so far.

 

That would clean up the inside of my cab like no tomorrow.

 

I skipped the gauges everywhere part of turbocharging with the Haltech. I still just use my stock gauge cluster, no AFR readout or boost... just tach and speedo haha. I have all of the failsafes configured though to avoid disaster should the AFR skew too far or over-boost occur... etc. We were talking about this over the weekend, but the Haltech has basically allowed me to have the closest thing to a stock turbocharged tacoma... not in hardware or power really but in feel. It just works and I think I could put anyone behind the wheel without worrying about how they'll drive it or how it will behave.

 

Do you have a scope/waveform of this? Was about to feed a 5V signal through a 10k resistor and use the HT to pull down the SP1 trigger at a frequency inversely proportional to the vehicle speed fed in already by SP2... wondering now if that isn't enough

edit: this is to feed the correct speed to my factory speedometer

 

I didn't save the o-scope view of it no. But you can capture it yourself pretty easy, just jump the cluster in and out and ground the sensor, the speed fed to your HT at that point on the VSS input is the unfiltered SP2. What's your plan for it here?

 

It sounds like I should be ok since it's on the feed into the combi cluster, not on the way out...curious still what this delay you're talking about looks like. The FSM for SP1 was always too vague

 

If you're willing to tear down the factory speedo, you could probably just extract and retain the smoothing circuitry and tuck it in the dash somewhere behind the IC-7/10.

 

The FSM description sucks, but for who it's made for I suppose it's acceptable. The stock trans controller and ECU (both stock and haltech) are fine with the unfiltered signal. Only cruise has a fit with it. I didn't have enough time with the truck to dive into that further and the CC has almost no diagnostics ability and there's no documentation explaining what it wants. But from the symptoms it was exhibiting and the series of events that led to it, it can really only be the SP1 signal without the "square wave refinement" that was causing it.

 

That crossed my mind, likely a good solution too for anyone not doing trans control. Once trans control is implemented the cruise won't be able to unlock the TC or disable OD so I didn't bother with the limited time we had. The CC works just fine for holding speed, just never allowed lockup to occur.

 

Interesting. Good thing I deleted my CC a while ago I guess lol... but I did want to try to fit it back in someday.

Maybe I'm looking at the wrong diagram, but CC has no control over SL? Haltech could independently trigger lockup either way. CC is only supposed to control speed via throttle and trans control (w/CC) is therefore dependent on where CC puts the throttle position & current speed