Z31 aircond sw

[bsdkllr]

i have noticed on my 86 turbo that the aircond sw is always activated, regardless of the a/c on or off. i checked the signal to the ecu and its showing 0 and 12v. but its still showing on.

does nistune do anything with this information? the a/c trigger is directly wired to a ficd.

[Matt]

Do you notice the compressor turn on/off when the switch is enabled (and fan on?). Just wondering if it is getting misreported by the software in this case. What is the ECU ID?

[bsdkllr]

the air conditioner turns on an off fine. im not sure if the ecu itself is damaged. does it affect fueling, idle speed or timing?

A18-655 M35

[bsdkllr]

Is there a way to see the raw data coming in? I have been trying to trace where on the ECU the data line goes from the pin. I'd have to guess this pin on the ECU is pulled to ground normally.

I have also been comparing ECU boards. I have 3 86 ecu's only 1 turbo board. But 2 non turbo boards. One however is a factory refurbished unit with only one rom. And what looks like a resistor pack where the second one would go.

[Matt]

I don't have the 1986 ECU Z31 ECU hardware here, but I think CR31 are the same, so will need to check it

In File > Config > Misc > User mode > expert mode

After restarting Nistune, there is a RAM memory monitor

Monitor address 0011 for 1986-1989 Z31/R31 ECUs

Digital control register 1

const BYTE CONSULT_REG_AIR_COND_SW = 0x10U;
const BYTE CONSULT_REG_NEUTRAL_SW = 0x04U;
const BYTE CONSULT_REG_START_SW = 0x02U;
const BYTE CONSULT_REG_CLSD_THL_POS = 0x01U;

Other values are not known/displayed outputs for R31/Z31

These also will display in the Raw View window (expert mode)

[bsdkllr]

i will give that a shot. i did order an additional ecu identical to the one i have just in case. it was cheap so i figured why not.

[bsdkllr]

new ecu same issue. i think its just not reporting.

[Matt]

What does address 0011 show in the RAM monitor?

[bsdkllr]

i couldnt find anything called memory monitor. i have consult ram tracer.

[Matt]

Thats the one "Consult RAM tracer"

I'm not sure which firmware you are running, so I'll try two with Z31 ROM on an RB30 ECU here

Pin 22 is the air cond input on the 1986 ECU. It needs 12V to activate inside the ECU

18P03 ECU ID:

1986 VG30E 18P03 AC.png

(26.44 KiB) Downloaded 1530 times

Your ECU 19P13 (19P12 is cloest match in the ROM pack)

1986 VG30ET 19P12 AC.png

(31.35 KiB) Downloaded 1530 times

Address 0011 changes from 0x28 to 0x38 when the AC input is changed (0x10 is the value used to indicate on/off)

I've noted that using 26P00 (26P0F feature pack) forces 0011 to be D8 on this ECU, regardless of switch input. So your switch input is correct. I'll need to check this out further. I assume you have the 26P0F 1988 ROM here

[Matt]

Okay further investigation shows there are differences to the Z31 hardware with regards to that switch input, and also potentially the fuel temperature input between 1986 and 1987/1988 hardware

Does your Z31 fuel temperature input look okay in the Nistune display (matching actual temperature?)

Several options
1. Leave it as is in the meantime, since this is the only issue
2. Reflash to non feature pack firmware for 1986 currently
3. I do a feature pack firmware for the 1986 model.

Actually I've written up the proposed 1986 FP code today (took a few hours, porting from the 1986 R31 RB30 code) but need to debug and test it still. Get the board reflashed with this once that is done

[bsdkllr]

I am running the feature pack rom. And fuel temp is just set to 25c from the settings. Also I don't have a neutral switch and did some testing on that too. That doesn't detect the neutral switch either. That shows it off all the time.

I had/have a nistune that has the non feature pack that was installed in an 86 non turbo ECU. And ac and fuel temp did work. I'm curious as to whether the non feature pack board will work on the turbo board.

The non turbo ECU got wet and seems to have died or the nistune board may have gotten corrupt.

[Matt]

Okay so the switch settings and the fuel pump is different between 1986 and 1988 firmware

The non turbo feature pack ROM file 19P12 (Z31 1986 VG30ET) works with the turbo/non turbo ECU board. So that can be flashed in the board currently

Otherwise give me some time to finish up the 19P1F firmware (using 19P12 as the base ROM) and we can put that in the board to fix those things up

[bsdkllr]

My spare nistune board seems to be corrupt. It does not turn the fuel pump on and when I try to connect. It says it's connected but to check maf voltage.

[Matt]

Sounds like it is corrupted, so needs a reflash. Might be best to do both at the same time