DIY PGMFI Diagnostics - Codes

[ECU-MAN]

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!





Aim:

Read fault codes from PGMFI ECU to Diagnose and Repair the PGMFI system on your Honda.


Required:


- a Honda with a fault
- the ignition key

- Short Connector or bent paperclip
- the two pin SCS connector

or a scan tool and the 3 pin DLC connector.



The aim of this DIY is to find and diagnose a fault with your fuel injection system. Commonly known on Honda's as the PGMFI system. PGMFI is short for Programmed Fuel Injection.

This DIY covers the codes found on AUDM cars, although it can be adopted to JDM and USDM. These codes are the same for OBDO, OBDI, OBDIIa and OBDIIb. To retrieve codes from an OBDO vehicle you simply have to turn on the ignition switch to position II and look at the window on the PGMFI ECU and count the codes out from the flashing red LED, however on OBDI and OBDII cars, you are require to bridge what’s called "SCS" service check connector then turn the ignition on to position II, the yellow engine lamp on the dash known as "MIL" Malfunction Indicator Lamp will blink the codes.

Below is a list of fault codes found in the Honda PGMFI system.


0 ECU - Electronic Control Unit
1 O2A - Oxygen sensor #1
2 O2B - Oxygen sensor #2
3 MAP - Manifold Absolute Pressure sensor
4 CKP - Crank Position sensor
5 MAP - Manifold Absolute Pressure sensor
6 ECT - Engine Coolant Temp sensor
7 TPS - Throttle Position Sensor
8 TDC - Top Dead Centre sensor
9 CYP - Cylinder Position sensor
10 IAT - Intake Air Temperature sensor
12 EGR - Exhaust Gas Recirculation lift valve
13 BARO - atmospheric pressure sensor
14 EACV - (IAC) - Electronic Air Control Valve
15 IOS - Ignition Output Signal
16 INJ - Fuel Injectors
17 VSS - Vehicle Speed Sensor
19 ATLC - Automatic Transmission Lockup Control Valve
20 ELD - Electrical Load Detector
21 VTS - VTEC Spool Solenoid
22 VTP - VTEC Pressure valve
23 KS - Knock sensor
41 PO2H - Primary Oxygen Sensor Heater
42 SO2H - Secondary Oxygen Sensor Heater
43 FSS - Fuel Supply System



- click on the fault code number above for an example of the MIL

- click on the sensor name for a DIY diagnostics of the sensor


STEP 1


locate your SCS connector. its a blue two pin female connector that looks like this.










STEP 2


Plug in the Short Connector. If you don't have a short connector use a paperclip to bridge the two metal pins in the connector. see pic below





I have made my own Short Connector from an old harness I had. I put a switch on the end, this helps for when you work with SRS and ABS systems.




STEP 3

Turn on the Ignition Switch to Position II, but do not start the car. If the PGMFI system is all OK, then with the Short connector plugged in and the Ignition ON, you will get the MIL stay on constantly with no flashes. see below picture MIL is shown in yellow circle





If you are having troubles with your car, then it may be related to the Ignition system like Ignition leads or coil or even a blocked fuel filter or air filter, main relay or fuel pump. The computer cannot monitor these and will not know if they are at fault.





STEP 4

Record the fault codes on a piece of paper so you can cross reference the codes. The Codes are flashed out as followed.


Tens are represented by a long flash of the MIL
Units are represented by a short quick flash of the MIL

example, code 43 ( fuel supply system )

long long long long quick quick quick


the ECU will pause for two seconds and repeat the fault code again. read the codes out at least twice to make sure you have the correct code recorded.

it is possible to have multiple codes in the ECU, if you do, you get 1 code then a 2 second wait then the next code.

below is an example of code 43 and to the right code 41 and code 1


...............................................






A trap for noobs.

- don’t confuse code 10 for code 1
- don’t confuse code 1 for code 10
- don’t confuse code 2 for code 20
- don’t confuse code 20 for code 22
- don’t confuse code 20 for code 2

you get the picture



that’s it, you have read the fault codes out of the ECU. now if your brave, click the link ( if it exists ) of the code you have and try to diagnose and repair the problem.


look bellow for SCS, ECU locations and on how to reset the ECU.



OBDO

for OBDO cars locate the the ECU which is usually under the passangers floorwell carpet. Pull the carpet back and you should see this






- located in the green circle in the pic above is a hole with a red LED in it. If there is a fault code stored in ECU memory it will blink out the code an the same manner as described above with the MIL when the ignition switch is in the II position. If all is OK with the PGMFI system then you will get a quick flicker of the LED when the ignition switch is turned on and the LED will stay off.




.



Note: I nor OzHonda.com take no responsibility if you mis-diagnose or simply replace a sensor for no reason and get stuck with an expensive part you can’t return.

Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!

[ECU-MAN]

SCS location


bellow is a list of cars, click on the link for a picture of the SCS location



- 1992 to 1996 Preludes

- 1997 to 200x Preludes

- 1992 to 1995 Civic EG

- 1996 to 2002 EK, EM , EJ

- 1992 to 1997 CRX EG2

- 1999 to 2005 S2000

- 1990 to 1993 Accords

- 1994 to 1996 Accords



If anyone has a picture of the SCS location not listed here please send it to me to help update the list

[ECU-MAN]

Reset ECU



Reset the PGMFI ECU

most OBDI and OBDIIa and OBDIIb cars is just a matter of finding the 7.5Amp backup fuse in the underhood fues box and pulling it out for 3 or so seconds. Anything longer than 10 seconds really is a waits of time.





*** note the above picture is a guide only and may not show the actual fuse you should pull in your car. ***


If you cant find the fuse or are having trouble resetting the ECU, then you can remove the negative battery terminal ( for 3 to 10 seconds ) to clear the ECU memory as a sure way to get it reset. This method isn’t the best as you have to put in the radio code and reset the radio station presets plus the clock.


There are lots of myths going around like remove the fuse for 10 minuets or disconnect the battery and turn on the head light and touch the battery terminals together to drain the power from the ECU ect. All false.



For the S2000 you have to remove the 30A backup fuse in the underhood fuse box.








After resetting the ECU with OBDO and OBDI cars your right to go. However with OBDII cars you have to "learn" the idle load parameters to the ECU. This can be done by turning off all electrical accessories in the car ( turn everything off in the car and only let it idle ) and allowing the car to idle until the thermo fans kick in and out at least twice. Then turn off the car and your done.


No need to drive the car and rev it to redline or anything else like that.



Thanks to CRXer, here is the ECU reset fues for 1988- 89 GEN II CRX with OBDO




Disclaimer: The following is provided as a GUIDE ONLY, and neither myself nor Ozhonda take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!

[ECU-MAN]

code 19 coming soon !!!

[wynode]

People are gonna go crazy when they see this!

PS: Sif bump your own threads

[TheGoodDeal]

Excellent write up, very details, clear picture & examples and confusion point out.
Thanks!!

[CRXer]

WTF!!!!!!!!!!!!!

Holy crap,this should be stickied to every tech section of every honda forum that ever existed.

At least sticky it to the top of the DIY section,it would be easier to link up to every question that was ever asked.

Heres my humble contribution:

ECU LED location for OBD0 versions(maybe should put in the SCS location post)


ECU reset fuse for CRX gen2 & prob other similar era cars like integra.Marked "HAZARD" fuse.


PS: must spread rep around,blah,i owe u one

[xedent]

I have a 96 ej8 coupe and i cant find the SCS connector even if i look at the pic that you uploaded for my car, its not there, there is only the yellow one behind it.

[ECU-MAN]

try looking on the oppisite side where the ecu is.

[xedent]

try looking on the oppisite side where the ecu is.

I have looked under there all, cant find anything

[dynosaur]

well done , ECU-MAN

[ECU-MAN]

I have looked under there all, cant find anything

have a good look near the ecu area on the left kick pannel, it might be tucked in under there, you may have to remove the cover for a good look. look hard you will find it in a green rubber holser along with the 3 pin DLC connector..

well done , ECU-MAN

thanks dude