DIY Honda ECU Repairs- P30 P08 P27

[E-Tech]

hi etech

still have 3 0bd1 small ecu sitting in my bench..

1.p08
-cel always on, no codes just constant CEL on
-no signs of damage , starts but high rpm at idle

2.p08
-code 21 vtec
- car wont start
-main relay ok
-fuel pump ok

3.p70
-chipped
- running at stock - ok no cell no problem on idle
-running at chipp - constant cell- rough idle- bad smell ok exhaust
(history) out of the factory with external chip but soldered on the board.
lost the factory 28 pin chip so used sst base map p28.

1- auto ecu on a manual car?
2- caps change and ic17 then qm3 if no damage on the traces.
3- it on limp mode due to chip not match or problem.
Or when you took out the original chip, you damage some copper trace.
Measure all continuity form chip to latch IC and main IC. Or remove the
Socket and check properly.

 

[ryand]

1- auto ecu on a manual car?
2- caps change and ic17 then qm3 if no damage on the traces.
3- it on limp mode due to chip not match or problem.
Or when you took out the original chip, you damage some copper trace.
Measure all continuity form chip to latch IC and main IC. Or remove the
Socket and check properly.

1.yes auto ecu on manual car but i remove rp17 and jumper rp18. and i cannot get CEL codes since its constant cel

2. ill try changing the caps.. i changed QM3.. do i need to change ic17? car fuel pump turns on and relay ticks.. and cel code is only 21 for vtec.. i have non vtec car

3.ill try check continuity but if copper is damage. it will check engine also in stock mode( jumper j1 remove)

tnx for your answers

 

[E-Tech]

How?.....

 

[levin818]

Hi E-Tech, need your advice on the following issue...
I have a P27 ECU that mod in IC13, IC14, HC373, 27256, and the necessary surrounding components to support VTEC. It is now supporting a B18C engine via an OBD1/OBD2 converter.
Everything seems to works fine until it throw out code 1 (O2 sensor) after few minutes run....
The code will be missing if the owner swap in the ori B18C ECU. So it is quite obvious that the problem came from that P27.
I have yet to take back the ECU for inspection but my doubt is, can P27 ECU reconize B18C's O2 sensor?
Your advice is much appreciated.

 

[E-Tech]

Dear moderators.......
Found my pictures here..... Zth is ok???!!!

tacra's diy garage: ECU Capacitor (ecu caps)

---------- Post added at 07:58 AM ---------- 6 hour anti-bump limit - Previous post was at 07:56 AM ----------

Hi E-Tech, need your advice on the following issue...
I have a P27 ECU that mod in IC13, IC14, HC373, 27256, and the necessary surrounding components to support VTEC. It is now supporting a B18C engine via an OBD1/OBD2 converter.
Everything seems to works fine until it throw out code 1 (O2 sensor) after few minutes run....
The code will be missing if the owner swap in the ori B18C ECU. So it is quite obvious that the problem came from that P27.
I have yet to take back the ECU for inspection but my doubt is, can P27 ECU reconize B18C's O2 sensor?
Your advice is much appreciated.

Hi Levin...
You missing a resistor for O2 function.
Original P27 do not support it.
pM for answer.....
Tq....

P/s too many copycat here that post copied info and pictures direct to their blogs!!!

 

[LOPI]

Bro E-TECH...
how about VAFC? can you fix it...tq

 

[E-Tech]

Bro E-TECH...
how about VAFC? can you fix it...tq

Hi..... So what is the problem?
No display or cannot function?

 

[levin818]

Hi Levin...
You missing a resistor for O2 function.
Original P27 do not support it.
pM for answer.....
Tq....

P/s too many copycat here that post copied info and pictures direct to their blogs!!!

TQVM! Just check an ori P27 ECU and found that no O2 support components there... So have to recall back the ECU for modification! Tks man!
The moment you start this topic, you can't stop the copy cat... unless you limit the information sharing to the ppl that you know only.
IMO, some information is too dangerous to share. For eg, if a DIY enthusiasm successfully repair their ECU according to your info, that is fine. But if he failed, he may drove his car to the drain... So for critical item like ECU, information sharing got to be very careful.

 

[E-Tech]

Please diy at own risk!!!
Service can be provided if you value ur car.... :-)

 

[E-Tech]

The the chance to mount the newest version of Hondata 300 V2 on a P28 ecu.
Here are the pictures..... It is a RED Hondata brd.

 

[nemiers]

Hi,

Hello to everyone, first post :wavey:

Would like to have some help from E-Tech with this ecu I have got, it has solid cel.
But to replace the ordinary parts which brake down, this ecu seems to have some parts desoldered, maybe that is the problem. I`ll put some pics here.
Thanks for any help!!!

 

[E-Tech]

Hv pm you....pls try.

 

[E-Tech]

Hondata S300J V2 in a P08...

 

[tamtam]

Car: Honda Civic EF
Engine: Carb to D15B vtec
ECU: P08 JDM rechipped box and P08 JDM stock box
Wirings: Okay except that i recently discovererd that the car has no main relay - Fuel Pump is directly connected to the ignition switch/key


Car is running fine. No CEL or whatsoever. Recently, I borrowed my friends Rechipped/Programmable ECU to test the CROME's launch control feature in my car. I just plugged in my friend's ECU and viola! my car runs aggressively and the launch is soooo cool!

Here's the bad thing happened, after the test, my friend plugged in the Programmable P08 back to his car and suddenly his car wont start! :( :O my friend borrowed my Stock P08 ECU and then tested it in his car, same scenario happened, his car also did not start! :( we borrowed a stock ECU from another friend and my friend's car started and ran fine. I think both ECUs are now broken. (my stock p08 and the programmable p08 ecu of my friend) :(

Troubleshooting1: (friends car): Using the recently working Programmable P08 and my Stock P08 box
- No CEL
- ECU startup ok (check engine turns on then off)
- The main relay is not clicking
- The fuel pump is not priming (checked the fuel rail no gas)
- Checked the iginition (there is spark in the plugs - distributor)
- Car won't start

Troubleshooting2: (friends car): another p08 ECU from another car
- No issues
- Car runs fine.

Another test: My friend's programmable P08 ECU and the stock P08 ECU when plugged in my car is working perfectly fine. It is just that both ECUs now wont let his car start. We also tested both ECUs to other car and the same scenario happened.

Conclusion: The stock P08 ECU and the programmable P08 ecu is Broken :( It is only working in my car! and these two ECUs are not working to other normal cars.

Findings: My Civic EF has no main relay! I guess the wires are directly connected to the ignition switch. Fuel pump is bypassed :-S

Solution: Restore the wirings back to original. Install a main relay.


Now, my Big Question is: How do i fix broken ECUs, what components do i need to check and replace? When i look at the programmable p08 box of my friend, i cannot see a trace that is broken or a component that is damaged. I need to fix my friend's ECU. Please help.

 

[E-Tech]

definately your previous wiring has caused the component related to original fuel pump to blow...
ur car it directly wired to fuel pump and always on even if engine not running...tat is dangerous
you need me to fix the ecu it....let me know....