MAFT Pro / LC1 connection problem?

[pb92supraturbo]

I'm finishing up the wiring on my MAFT Pro and powered it up to make sure I'm getting good signals from all the sensors. When I switched to the monitor display and set AFR as one of my displayed items, the AFR displayed didn't match what my XD-16 gauge was showing. Also, when the MAFT Pro is first powered up, it takes over thirty seconds for the AFR to register(long after the LC1 has completed its sensor warm up and is registering AFR). I've wired the LC1 analog output 2(brown) to the 10 pin orange wire, and LC1 analog ground(green) to the 10 pin purple wire. If I disconnect the 6 pin sensor harness from the MAFT Pro and power it up, I get the same AFR value, which leads me to think the wiring isn't correct. I've verified the analog output on my LC1 is working by connecting my multimeter to it and I get 4.95 volts with the ignition on but car not running.

I'm thinking my problem is connecting the LC1's analog ground to the MAFT Pro's 10 pin purple wire. I think both these wires need to be grounded at the same point. The MAFT Pro wiring diagram is sort of misleading in that both these ground wires are shown connected together, but not grounded. Is this my problem? Also, should the AFR show on the MAFT Pro match exactly what is being displayed on the XD-16 gauge? BTW, My LC1/XD-16 combo has been installed over a year and worked flawlessly.

 

[drjonez]

the first question is what do you have the MAFT pro's WB input set to?

the second is have you looked at the LC-1's output settings? ensure that the output scale of analog 2 is the std. linear 0-5V, warmup/error conditions are set to 5V, response = instant.

...I'm thinking my problem is connecting the LC1's analog ground to the MAFT Pro's 10 pin purple wire. I think both these wires need to be grounded at the same point. The MAFT Pro wiring diagram is sort of misleading in that both these ground wires are shown connected together, but not grounded. Is this my problem? Also, should the AFR show on the MAFT Pro match exactly what is being displayed on the XD-16 gauge? BTW, My LC1/XD-16 combo has been installed over a year and worked flawlessly.

your thinking is incorrect and the diagram isn't misleading at all. the MAFT pro measures the WB input differentially, hence the need for the purple wire (signal ground). you do not need to reference the MAFT pro's purple wire or the LC-1's green wire to chassis ground.

where are the white + blue wires from the LC-1 grounded to? where is the MAFT pro grounded to? where are both the LC-1 and MAFT pro powered from?

 

[pb92supraturbo]

the first question is what do you have the MAFT pro's WB input set to?

MAFT Pro is set to 1 - LC1

the second is have you looked at the LC-1's output settings? ensure that the output scale of analog 2 is the std. linear 0-5V, warmup/error conditions are set to 5V, response = instant.

LC1 analog output 2 has been reset to default settings. I remember the linear scale being correct. I can't remember if warmup/error conditions and response match what you listed - I'll double check.

where are the white + blue wires from the LC-1 grounded to? where is the MAFT pro grounded to? where are both the LC-1 and MAFT pro powered from?

LC1 white and blue are grounded in the cabin to the metal substructure under the dash, passenger side kick panel. MAFT Pro is grounded at the same location and I've verified that this is a good ground point. LC1 and MAFT Pro are powered from the driver side cabin fuse block 20 amp wiper circuit - switched on in ignition 'on' position.

Does the MAFT Pro need to be wired to a '+' lead that is on in the accessory position? I thought I read a thread where someone was getting an error code for air temperature signal or AFM from the ECU because the MAFT Pro took a bit longer to boot up than the ECU. Also, should the AFR reading on the MAFT Pro sensor monitor page match exactly what is being displayed on the XD-16?

 

[drjonez]

the MAFT pro doesn't NEED to be wired to an ACC + feed, but it will eliminate the intake air temp and HAC codes the ECU throws (because the ECU boots faster than the MAFT pro does).

yup, the MAFT pro's AFR reading should match the XD-16. mine does, several customer cars do as well. what are you reading for the O2 parameter? that's the raw V the MAFT pro is seeing on the WB input.

 

[pb92supraturbo]

LC1 Response speed is set to instant. "Warmpup" output and "Output at error cond." are both set to high impedance. Do I need to uncheck 'high impedance' and set both to 5v?

I'll check the MAFT Pro raw V now . . .

the MAFT pro doesn't NEED to be wired to an ACC + feed, but it will eliminate the intake air temp and HAC codes the ECU throws (because the ECU boots faster than the MAFT pro does).

yup, the MAFT pro's AFR reading should match the XD-16. mine does, several customer cars do as well. what are you reading for the O2 parameter? that's the raw V the MAFT pro is seeing on the WB input.

 

[pb92supraturbo]

yup, the MAFT pro's AFR reading should match the XD-16. mine does, several customer cars do as well. what are you reading for the O2 parameter? that's the raw V the MAFT pro is seeing on the WB input.

Where do I view raw voltage the MAFT Pro is getting within TunerPro RT? I checked both aldl dash and values but didn't see value as an option to add or view. I checked purple and orange wires at the connection and am getting 4.3 -4.4v with the engine off on my multimeter - XD-16 is showing 19.6 to 19.8 AFR. MAFT Pro is showing 21.~ AFR. If I disconnect the orange/brown connection between the LC1 and MAFT Pro, the AFR displayed in TunerPro drops to 7.~ AFR. I'm stumped . . .

 

[drjonez]

like my post said, look at the sensor monitor (or in tunerpro), what value is being displayed for the O2 parameter?

 

[pb92supraturbo]

yup, the MAFT pro's AFR reading should match the XD-16. mine does, several customer cars do as well. what are you reading for the O2 parameter? that's the raw V the MAFT pro is seeing on the WB input.

Never mind ... I found raw v - o2 sensor voltage - duh! XD-16 is showing 19.5 - 19.8 AFR, MAFT Pro is seeing 4568 to 4575mv and reporting 21.~ AFR. For whatever reason, they aren't synchronized . . . I'm still stumped.

 

[pb92supraturbo]

like my post said, look at the sensor monitor (or in tunerpro), what value is being displayed for the O2 parameter?

See screenshot ...

 

[drjonez]

interesting stuff. what does your voltmeter say?

 

[Justin]

the MAFT pro doesn't NEED to be wired to an ACC + feed, but it will eliminate the intake air temp and HAC codes the ECU throws (because the ECU boots faster than the MAFT pro does).

I know this thread is old, but instead of starting another one.....

I don't understand how wiring it to acc would help. When you turn the key to 'start', 'acc' drops power, while ignition retains power. How would having the maft pro drop power while the vehicle is starting, help it boot faster?


learn me please!

 

[drjonez]

I know this thread is old, but instead of starting another one.....

I don't understand how wiring it to acc would help. When you turn the key to 'start', 'acc' drops power, while ignition retains power. How would having the maft pro drop power while the vehicle is starting, help it boot faster?


learn me please!

perhaps you missed the "+ feed"....or perhaps i should have called it something better. you'll need to wire it to an ACC ine AND a B+ @ the ECU....basically separate the two by a diode to prevent the B+ from charging the ACC....then pause for a second @ the ACC position when starting, giving the MAFT pro a "head start" in booting....

 

[Justin]

perhaps you missed the "+ feed"....or perhaps i should have called it something better. you'll need to wire it to an ACC ine AND a B+ @ the ECU....basically separate the two by a diode to prevent the B+ from charging the ACC....then pause for a second @ the ACC position when starting, giving the MAFT pro a "head start" in booting....

Yeah, I guess I'm not understanding. You're saying to wire the pink wire, which in the instructions it says to wire into B+ (which is switched power, correct?), to constant and switched power? I'm afraid I don't understand.

Secondly, the instructions say to wire the brown wire to THA. If I were to jump E2 and THA with a resistor, wouldn't that throw off the reading the ECU sees?

I'm only digging into this farther because I put a resistor in and I'm still getting a code 24.


Thank you for the help Adam.

 

[drjonez]

Yeah, I guess I'm not understanding. You're saying to wire the pink wire, which in the instructions it says to wire into B+ (which is switched power, correct?), to constant and switched power? I'm afraid I don't understand.

eh, i guess i can't explain what i mean, forget about it.

Secondly, the instructions say to wire the brown wire to THA. If I were to jump E2 and THA with a resistor, wouldn't that throw off the reading the ECU sees?

THA is the ECU's air temp sensor input. the idea with the MAFT pro install is to have the MAFT pro output a constant voltage to THA to keep the ECU happy. the MAFT pro takes intake temp into account in it's speed density calculation. putting a resistor in between THA and ground (E2) fixes the voltage that the ECU sees....thus doing the same thing as the MAFT pro does, just without the difference in boot up time.

I'm only digging into this farther because I put a resistor in and I'm still getting a code 24.

what value did you use? how did you wire it up?

 

[Justin]

eh, i guess i can't explain what i mean, forget about it.

If its all the same I'd really rather not. I'm curious now We could take it to PM, or AIM if you'd prefer...

THA is the ECU's air temp sensor input. the idea with the MAFT pro install is to have the MAFT pro output a constant voltage to THA to keep the ECU happy. the MAFT pro takes intake temp into account in it's speed density calculation. putting a resistor in between THA and ground (E2) fixes the voltage that the ECU sees....thus doing the same thing as the MAFT pro does, just without the difference in boot up time.

Very Good, I understand. By looking at the diagram I was under the mis-impression that the maft pro output a signal, not a constant voltage to mak ethe ecu happy.

what value did you use? how did you wire it up?

2.4k, and I just put it in the plug between THA and E2

 

[GotTurbos?]

I figured this would be the best place to post this instead of making a new thread, I am constantly having problems with my wideband and maft pro. I finally get it calibrated, then it reads slow, then it seems just to be way off, and now it is back to not reading at all (constant 22.x or 8.x) I wouldn't complain if it had been forever since I last calibrated it, but its only been a few weeks. I have never run race gas or even more than 12psi (not like that really matters) The tune on the car is decent too, so I have no idea whats causing the problem. Any ideas?

 

[Justin]

I figured this would be the best place to post this instead of making a new thread, I am constantly having problems with my wideband and maft pro. I finally get it calibrated, then it reads slow, then it seems just to be way off, and now it is back to not reading at all (constant 22.x or 8.x) I wouldn't complain if it had been forever since I last calibrated it, but its only been a few weeks. I have never run race gas or even more than 12psi (not like that really matters) The tune on the car is decent too, so I have no idea whats causing the problem. Any ideas?

Do you have the XD16 gauge, or are you just going by what the Maft tells you?

 

[GotTurbos?]

Going by what the maft tells me. Would a gauge make any difference?

 

[drjonez]

sounds like a wiring issue....if you're not reading anything @ all intermittently.

 

[GotTurbos?]

Its not intermittently, It will get progressively worse until it stops reading. I just redid the wiring on it a couple weeks ago (had the wrong input wire before) and it is all still fine. It just seems to go dead unusually fast.