[Mk2] [Turbo] AP Engineering Power FC Issues

[gtfour-wrc]

Hi All,

I am in the process of installing an AP Engeering Power FC into my 1990 Celica GT-Four. The Pinouts are very similar to the Rev2 1990-91 SW20.(except for PS/ABS)

I've repinned the harness and the car starts and drives with no CELs on a JDM ECU Part# 89661-17380 (which the AP PFC is made for).

The car starts and idles fine with the PFC though I have a constant CEL on the dash and the commander displays the sensor 'THE' with a black box and 0.00v.

Searching the forum has advised that 0.00v with a black box is a short circuit. Though I can't find what 'THE' stands for.

I have not wired in any other sensors. These are only needed if removing the AFM.

Does anyone have any ideas??

Thanks

[Race Idiot]

iirc the AP engineering pfc doesnt use the afm anyway, just uses the standard rev2 pressure sensor so still needs a mat and ait sensor to work correctly.

I'd ask this question on mr2oc.com as thats where I gathered most of my information on the ap engineering pfc.

What it looks like is the ap engineering is just a standard gen3 pfc (d-jetro model) modified to work with the gen2 engine sensors. So it doesnt use the afm anyway.

[gtfour-wrc]

Thanks Race Idiot.

I've posted here also since a few more UK boys have played with this AP model compared to the US boys.

[dex]

'THE' is the aircon evaporator temperature sensor.

[gtfour-wrc]

Dex - Are you 100% sure on this?

Unfortunately there's no real definate answer on the forums. Due to it being such a rare ECU

[dex]

Fairly sure. I did a lot of research into the codes that Toyota use for my rev2 to rev3 conversion. Incidentally, the UK spec ST205 loom does not have this pin connected up.

[jimGTS]

iirc the AP engineering pfc doesnt use the afm anyway, just uses the standard rev2 pressure sensor so still needs a mat and ait sensor to work correctly.

I'd ask this question on mr2oc.com as thats where I gathered most of my information on the ap engineering pfc.

What it looks like is the ap engineering is just a standard gen3 pfc (d-jetro model) modified to work with the gen2 engine sensors. So it doesnt use the afm anyway.

thats incorrect.
the AP is designed to be used both with and without the afm.

ie, straight plug and play if you got an afm setup.
or rev3+ map based setup when you remove the afm and swap in the rev3+ bits. you just choose which map sensor option you want in the commander.

[gtfour-wrc]

thats incorrect.
the AP is designed to be used both with and without the afm.

ie, straight plug and play if you got an afm setup.
or rev3+ map based setup when you remove the afm and swap in the rev3+ bits. you just choose which map sensor option you want in the commander.

My thoughts exactly jimGTS and thanks for chiming in.

What confuses me is the AP Engineering PowerFC is Plug 'N' Play for the Rev2 SW20. This does not come with a MAT sensor standard.

I am able to plug a 93 JDM ECU into the harness and drive without any problems or error codes, Therefore I should be able to plug the PowerFC in without problems. No?

I had the Japanese instructions translated to English and these are the main instuctions...

Sensor check - Changing the display contents
-> Delete Data - VTA2, AIRT
-> Add Data - 1.(THE) Air Inlet Temp Sensor 2.(CCO) Exhaust Temp Sensor

Installing the Inlet Air Sensor
-> Install wires 5 & 7 from the AFM to the MAT sensor. (These wires control the IAT in the AFM)

Is there a way to remove/add sensors by using the commander?
If I wire the MAT sensor using the above AFM wires 'THE' will still show up because they run the AIRT sensor. Yes/No?
Would sensor 'THE' be the pinout 'THG' on the Rev2? (This is the only wire I have yet to allocate as the Rev1 doesn't have this pinout)
What PINOUT on the Rev2 reflects the Engine Bay/Lid Temp sensor?(I also have not got this allocated)

Thanks for you help.

[dex]

'THA' is the inlet air temperature sensor, part of the VAF on rev1/2 and in the airbox on rev3/ST205. Apexi call this 'AIRT'.

'THAM' is the inlet manifold air temperature sensor on rev3/ST205. Apexi call this 'AIMT'.

'THG' is the EGR temperature sensor, but since there is no EGR on UK spec rev1/2 this gets used for the THE input to the ecu, pin 10 of the 16 pin plug.

The engine lid temperature sensor is wired to the engine bay cooling fan ecu and is not connected to the engine management ecu.

EDIT: amended line regarding THG

[jimGTS]

surely that translation is just for when you want to go from afm to non-afm.

it should be plug and play.

yes, ap was only designed to plug and play into a rev2 jdm.

thg, tham, thg, e2, relate to the wires you need to mess with to put in the ait and mat sensor WHEN you go to rev3+ map sensor based electronics.

you shouldnt have to install any sensors.

[gtfour-wrc]

I've been reading this http://www.imoc.co.uk/forums/viewtopic. ... fc&start=0

Jim, MR2LOVER says the wiring should be MAT=THA, AIT=THG. Can you remember how you had it?

I've read the PFC Gen3 doesn't use the AIT for tuning anyway. Is this correct Gen3 PFC users?

Personally I think 'THE' is the EGR sensor (THG) and the reason it is in a black square and shows 0.00v is because I have not wired it as of yet due to my Rev1 not having a THG sensor.

In the thread above the sensors on the commanders change between Gen2 and Gen3.
On the Gen3 you get sensors...
PIM x.xxv
VTA1 x.xxv
VTA2 x.xxv
BOST x.xxv
WTRT x.xxv
AIRT x.xxv
AIMT x.xxv
O2S x.xxv

On the Gen2 you get...
PIM x.xxv
VTA1 x.xxv
BOST x.xxv
WTRT x.xxv
AIMT x.xxv
THE x.xxv
O2S x.xxv
CC0 x.xxv

dex says the Gen3 uses AIMT=MAT.
This leads me to believe that the AP model only requires 1 sensor wired in to THA=MAT=AIMT. Since this works correctly with the AFM in place and the instructions advise to use THA.(wires 5&7 of AFM harness)

THE=THG(EGR sensor). Gen3 doesn't have THE because they don't have an EGR sensor stock.

Does anyone know what tuning purpose the EGR sensor is used for or the CCO(Catalytic Converter Sensor) for that matter?

You guys follow my thoughts?

[jimGTS]

bare in mind, i had issues because the AP was broken!!! it wasnt firing cylinder 1!

also bare in mind, i was using the AP to run rev3+ electronics...so i had wired it up to run 540s, rev3 map sensor etc etc.
i never actually tried to plug and play it unfortunatly with the afm still on there.

[gtfour-wrc]

Thanks jim.

I've wired my harness to Rev2 spec minus THG and CCO.
A Rev3 Map Sensor is installed
440cc injectors

It starts with the AP PFC installed with AFm attached. It drives fine, the only issue I have is the CEL is on constantly due to THE being left off.

When using the Rev2 ECU there is no CEL displayed.

So I'm wondering could I use THG and CCO for other sensors maybe? Like Oil temp and AIT. Basically just to monitor them? As I can't see them being useful for tuning?

[jimGTS]

you tried plugging back in your rev1/2 map sensor?

im really not sure about this "THE" sensor error tho.

this the first time ive heard of someone putting an AP on a rev1. so there cant be much if any info around.

i would try pm-ing someone who tunes power FCs, like Ryan at 2bar tuning
(mr2lover in my old thread, he tunes mr2s now)...

he may be able to help.

[gtfour-wrc]

Jim,

The AP runs perfectly with both the Gen2 and Gen3 MAP sensors.
This is the reason I think THE and CCO are basically useless sensors for tuning.

I'm waiting to see if someone with a Rev2 and OEM ECU chimes in to see if they can disconnect their EGR sensor from the ECU harness to see if they get an ecu code 71

or

IF someone with a Rev2 and AP PFC can disconnect their EGR sensor from the ECU harness to see if they get a THE error on their PFC Commander

Wishful thinking I know, but it is the WWW afterall!

I'll try PMing Ryan@2Bartuning.

Thanks for all your help

[dex]

EGR is used on California GT4's/MR2's and UK ST205's (I don't know about the earlier UK GT4's).

The CCO illuminates a warning on the dash on MR2 but because it goes via the ecu I also suspect that the ecu probably reduces boost and enriches the fueling when it thinks the catalytic converter is too hot.

No idea why the THE goes to the ecu unless it's used to affect decisions about aircon clutch engagement.

[Race Idiot]

thats incorrect.
the AP is designed to be used both with and without the afm.

ie, straight plug and play if you got an afm setup.
or rev3+ map based setup when you remove the afm and swap in the rev3+ bits. you just choose which map sensor option you want in the commander.

So your telling me the ap engineering unit is a D-Jetro and L-Jetro? Because that realy sounds like a hackjob on the part of ap engineering.

[jimGTS]

I've no idea what your refering to. But why make a rev2 ecu IF you have to put all the rev3 sensors on
The ap is designed to work with afm, 440s etc etc. Hense the 2 map sensor options, and hense why it cost 15-25% more to buy brand new as it has the ability to work with both.

[Race Idiot]

I've no idea what your refering to. But why make a rev2 ecu IF you have to put all the rev3 sensors on
The ap is designed to work with afm, 440s etc etc. Hense the 2 map sensor options, and hense why it cost 15-25% more to buy brand new as it has the ability to work with both.

The D-Jetro power fc's are ones that use a map sensor for fueling, like the normal gen3 one. L-Jetro ones are versions that use the afm, which other cars like skylines use.

http://paulr33.skylinesaustralia.com/do ... faq.htm#12

Being able to use the afm and switch to map would mean it's both types somehow.

[gtfour-wrc]

The AP Eng Power FC can work in both L-Jetro and D-Jetro setups. It is specifically made to be used as a D-Jetro setup but to use all Rev2 sensors. This is why the instructions mention the use of only 1 sensor the MAT wired to the AIT wires from the AFM harness. No mention anywhere on the extra document regarding an AIT sensor.

It can be used as a L-Jetro setup but would not be ideal as you will be tuning the Air Temp from the AFM and not from within the IM.

It's a Plug 'N' Play ecu for a Rev2 though most people opt for the Rev3 as it was cheaper to buy NIB when available.

I know quite a few JDM tuning houses purchased them from APEXI and applied their own branding to them for the 1991-93 ST185 GT-Four crowd. As they also used the Rev2 spec ECU

Unfortunately its rare and not many saw the shores outside of Japan.
Rev2(ST185v2 & SW20v2) motors inc. JDM all used EGR and EGR temp sensors.
Rev1(ST185v1 & SW20v1) JDM motors did not have EGR.
Rev1(ST185v1 & SW20v1) UK/US/Aus had EGR but no sensors, except California motors they had the EGR sensor aswell.

I've confirmed this by opening both Rev's of ECU for the SW20 (JDM & US)

I think the info and usage of the AP Power FC has been wrong in the past so I'm hoping we can finally get it sorted for all those who wish to use them in the future