JDM DC5 Alternator fault

[Knox]

Hello, today I bought a new plugin ecu for my customer jdm DC5 type r. I used the map inside the plugin ecu and when I start the engine aux 8 gives fault and also ecu voltage high error. I see that battery voltage goes up to 18v and goes to fuel cut on and off. When I check manual see that aux  8 is connected to alternator control. Even its auxilary output -> alternator control is none it tries to control I think. So, I make alternator control none to aux8 and tried to control the alternator but I don't know the pid settings etc. So I tried for proportional 3, integra 0.5, and derivative to 0.5 to 3 but nothing solves the issue. I tried a known map (map from a car before I tuned) and same issue again. I also checked with voltmeter on battery, charging goes upto 18 but with hondata ecu (customer has hondata kpro, he will sell it after link ecu tuned) charging never goes more than 14.2. First I think alternator have some issue but when I see it with hondata its ok, I want to ask here.  
Also I tried to reduce max clamp to 60 and nothing change.

Edited March 28, 2023 by Knox

[Vaughan]

In our testing the DC5 alternator control was a switched output with the alternator regulating to either 13v with the output on active low or 14v with the output off.

We have also seen on some other Honda vehicles (based on the one alternator part number I have been given it was a slightly newer civic) that the alternator control is PWM based with the ECU regulating the voltage (using the alternator control function).

Given that your car is seeing 18V I suspect that it might have an ECU regulated alternator, my recommendation would be to copy the alternator control settings from one of the NB MX5 sample maps and to set the Aux 8 active state to High as I suspect it is currently operating in reverse for you. Once you have done this please take a short PC log of you starting and running the car and then attach that and a copy of your basemap here please.

[Adamw]

I was just typing something similar to Vaughan.  All documentation I can find for the DC5 only mentions the "dual mode" charging system as Vaughan describes where it can only do normal voltage or low voltage, but I have seen a couple of reports from users that had very high voltage with aux 8 off.  They were all engine swap applications though so I assumed there must be some other model alternator.  

If you had the opportunity it would be really nice to know the frequency that the Hondata is using to control the alt - most modern multimeters have a frequency function if you dont have access to a scope.  I believe some PWM alternators can be fussy with frequency although 250Hz seems to be most common.

I think Vaughan's suggestion of trying the NB MX5 settings would be a good test.  Before you do your log, can you also go to PID Setup down the bottom of the ecu settings tree and set that to Alternator control so we get a log of what the control loop is doing.  

BTW, if the 18V fuel cut is preventing you from testing, you can go to >engine protection>sys voltage limit and adjust it higher there.  

[Knox]

On 3/28/2023 at 11:31 PM, Vaughan said:

In our testing the DC5 alternator control was a switched output with the alternator regulating to either 13v with the output on active low or 14v with the output off.

We have also seen on some other Honda vehicles (based on the one alternator part number I have been given it was a slightly newer civic) that the alternator control is PWM based with the ECU regulating the voltage (using the alternator control function).

Given that your car is seeing 18V I suspect that it might have an ECU regulated alternator, my recommendation would be to copy the alternator control settings from one of the NB MX5 sample maps and to set the Aux 8 active state to High as I suspect it is currently operating in reverse for you. Once you have done this please take a short PC log of you starting and running the car and then attach that and a copy of your basemap here please.

Thank you, MX5 setting looks like works very good. Only chage I make is, I used 23 for "Min clamp" because on idle when rpm drops little turns on battery sign if I use 10 for "min clamp"

On 3/28/2023 at 11:52 PM, Adamw said:

I was just typing something similar to Vaughan.  All documentation I can find for the DC5 only mentions the "dual mode" charging system as Vaughan describes where it can only do normal voltage or low voltage, but I have seen a couple of reports from users that had very high voltage with aux 8 off.  They were all engine swap applications though so I assumed there must be some other model alternator.  

If you had the opportunity it would be really nice to know the frequency that the Hondata is using to control the alt - most modern multimeters have a frequency function if you dont have access to a scope.  I believe some PWM alternators can be fussy with frequency although 250Hz seems to be most common.

I think Vaughan's suggestion of trying the NB MX5 settings would be a good test.  Before you do your log, can you also go to PID Setup down the bottom of the ecu settings tree and set that to Alternator control so we get a log of what the control loop is doing.  

BTW, if the 18V fuel cut is preventing you from testing, you can go to >engine protection>sys voltage limit and adjust it higher there.  

Sorry Adamw my mutlimeter did not have frequency option. So I couldn't meausre it but  250hz looks like work very good. By the way I record a small datalog if you want to check.
https://drive.google.com/file/d/1ggS_Rpsj2DKM9l4l1SH76vQ-vO7qqoK4/view?usp=sharing

 

[Vaughan]

Would you be able to give us any information on your specific car if possible? Things like what year is it, facelift or pre facelift, exact motor code, alternator part number, picture of chassis plate etc? This would help us narrow down which models need alternator control and which models are switched voltage levels.

Thanks

[Knox]

21 hours ago, Vaughan said:

Would you be able to give us any information on your specific car if possible? Things like what year is it, facelift or pre facelift, exact motor code, alternator part number, picture of chassis plate etc? This would help us narrow down which models need alternator control and which models are switched voltage levels.

Thanks

Car is 2004 jdm market integra dc5 type r. Motor code is K20A but motor is from jdm cl7 accord euro r (Accorda has different ecu normally so I think the alternator is different) also I looked to alternator there is no writing on it. I forgot to have picture but chassis is LA-DC5-220….. I road tuned the car yesterday and owner said when he turns on head lights battery light come on and off after 1-2 seconds. So I increased the minimum clamp to 25. I think he will not have issue again. 

[Vaughan]

Do you know if the alternator on it is the one from the jdm cl7 or is the original one from the DC5?

Thanks

[Knox]

11 hours ago, Vaughan said:

Do you know if the alternator on it is the one from the jdm cl7 or is the original one from the DC5?

Thanks

My customer bought the car as it is. So we are thinking complete cl7 engine swap with alternator but we are not 100% sure.