DIY PGMFI Diagnostics - Code 16 Fuel Injectors

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!


No part of this DIY is to be reproduced with out acknowledgment of the site and author it came from, ie me and ozhonda.com. Do not rip parts off and claim them as your own.



Fuel Injectors. The Fuel Injectors are commonly located on the front of Intake Manifold. The ECU pulses the fuel injectors to meter the amount of fuel going into the engine to the desired air fuel ratio. Injectors come in two types. Low impedance known as peak hold injectors, that require a resistor block, and High impedance known as saturated injectors.



Aim:

Diagnose code 16.

http://ecu-man.com/diy/pgmfi/mil/pgmfi-code-16.gif




Required:

Basic Testing

- Digital Multi Meter
- paper clip







Symptoms

Faulty Injectors will trigger code 16, you will more than likely get the engine light come on and the car will go into limp mode, Limp mode is a preset fuel and ignition map running on a backup processor in the ECU. Limited to about 3500rpm and a rich mixture to protect the engine the engine will run, but not the best. Common cause for code 16 is a faulty injector, open circuit in the wiring back to the ECU, possibly a faulty resistor block, or a faulty main PGMFI relay.


Basic Test


- Perform a Visual inspection and make sure the Injectors are all Connected


Injector Pin out Picture



http://ecu-man.com/diy/pgmfi/inj/PGMFI-inj-conn.JPG


wire side of connector



**** Resistance Test **** Set the multi meter to ohms ( 1k scale )


Unplug the Injector being tested, connect your Red multi meter lead to Pin 1 of the Injector. Connect your Black multi meter lead to Pin 2 of the Injector.


http://ecu-man.com/diy/pgmfi/inj/PGMFI-inj-res.jpg



for peak/hold ( resistor block ) you should get 2 to 3ohms

for saturated ( no resistor block ) you should get 10 to 13ohms


replace the injector(s) if its not within spec




**** Voltage Test ****




Set your multi meter to DC Volts ( 20v scale )

Step 1 ( Reference Voltage test )

Note: The reference wire could vary from Pin 1 or Pin 2, your best bet is to pick the yellow/black wire.

Check the Injectors for there Reference Voltage from the main PGMFI relay, Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the Injector with the Red lead to Pin 1 of the injector while the injector is disconnected.

KOEO* you must get 12v

Test all injectors


if you do not get 12v, repair open or short circuit to the ECU from Pin 1 of injectors
Note: If you have a resistor block check its resistance


If you do not get 12v from the yellow/black wire at the main PGMFI relay, replace or repair the main PGMFI relay.


OBDO = A13
OBDI = A25
OBDIIa = A11
OBDIIb = B1




**** Pulse Width Test ****

Time test, set your meter to ms scale


Check the Injector Signal. Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the Injector with the Red lead to Pin 2 of the Injector while the Injector is connected.


KOER* with a warm engine the Injector On Time should be about 2ms at idle

test all injectors


***** Its is always best to check sensor outputs at the sensor side *****






**** Duty Cycle Test ****

Time test, set your meter to duty cycle % scale


Check the Injector Signal. Connect the Black Lead from your multi meter to the chassis for a good ground. Back probe* the Injector with the Red lead to Pin 2 of the Injector while the Injector is connected.


KOER* with a warm engine the Injector On Time should be about 2% at idle
KOER* with a warm engine the Injector On Time should be about 6% at 2500rpm in N

test all injectors


***** Its is always best to check sensor outputs at the sensor side *****



**** Continuity Test ****


Set your multi meter to continuity. This setting is mostly a picture if a sound .))) when you touch the Red and Black leads together on your meter it should beep.


STEP 1

make sure the Ignition is off and unplug the Injector Connector and the ECU Connectors for this test

Continuity test between Injector Pin 1 and ECU, Connect your Red multi meter lead on the Injector Pin 1, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.


OBD0

inj 1 = A1
inj 2 = A3
inj 3 = A5
inj 4 = A7


OBD1

inj 1 = A1
inj 2 = A3
inj 3 = A5
inj 4 = A2


OBDIIa

inj 1 = A4
inj 2 = A3
inj 3 = A2
inj 4 = A1


OBDIIb

inj 1 = B11
inj 2 = B3
inj 3 = B4
inj 4 = B5



your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.


STEP 2 no resistor block ( saturated )

make sure the Ignition is off and unplug the Injector Connector and the ECU Connectors for this test


Continuity test between Injector Pin 2 and ECU, Connect your Red multi meter lead on the Injector Pin 2, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.




OBDO = A13
OBDI = A25
OBDIIa = A11
OBDIIb = B1


your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.





STEP 3 with resistor block ( peak/hold )

make sure the Ignition is off and unplug the Injector Resistor Block Connector and the ECU Connectors for this test


Continuity test between resistor block and ECU, Connect your Red multi meter lead on the resistor block Pin 3, Back probe* the Black multi meter lead on the ECU Pin bellow that suits your car.




OBDO = A13
OBDI = A25
OBDIIa = A11
OBDIIb = B1


Picture of Injector Resistor block Connector


http://ecu-man.com/diy/pgmfi/inj/PGM...stor-block.JPG

wire side view of connector




your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.




STEP 4 with resistor block ( peak/hold )

make sure the Ignition is off and do not unplug the Injector Resistor Block Connector for this test


Continuity test between resistor block and Injector, Connect your Red multi meter lead on the resistor block Pin X, X= injector being tested. Back probe* the Black multi meter lead on the Injector Pin 2 that is being tested.


Picture of Injector Resistor block Connector

http://ecu-man.com/diy/pgmfi/inj/PGM...stor-block.JPG


wire side view of connector




your multi meter should beep and read short or 000.0ohms. Place the black multi meter lead on a good ground source. You should not get beeping, this is testing for short to ground.




Test the Injector Resistor Block Set the multi meter to ohms ( 1k scale )


Injector Resistor block is usually mounted on the LH Shock tower near the firewall. most OBDO cars will have one. Accords and Preludes run a resistor block.



measure the resistance of the resistor block

http://ecu-man.com/diy/pgmfi/inj/PGM...stor-block.JPG

wire side view of connector

test between pin 3 and pin 1,2,4,5 individually with the Resistor Block disconnected.

You should get about 6 ohms.


if you get a much higher resistance or no resistance, replace the resistor block.



* Notes

KOEO = Key On Engine Off

KOER = Key On Engine Running

Back probe the sensor, use a paperclip and push it into the connector then touch/clip your multi meter lead to the paper clip


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!

I have code 16. I know for a fact that my relay was causing problems and I have resoldered it...so now the fuel pump is priming and relay clicking each time...but still having erratic starting problems when hot. Also the engine check light comes on at random times when driving. Why would it come on in the middle of driving??? If it was faulty injectors...wouldn't this lead to poor running of the engine??? My engine runs fine once started. If it's open circuit...could this still be the relay not being soldered properly? I guess I'll have to do all the tests above.

Hi

you either have a JDM, USDM car/ecu or a prelude. the injector circuit consists of the main PGMFI relay, a resistor block and the injector.

an injector doenst have to be open circuit to have a fault that causes code 16, the relay or resistor block could be faulty causing high resistance on the circuit and the ECU detects it.
check the relay contacts in the main relay, as the main relay feeds power to the ecU and injectors as well as the fuel pump,

check the resistor block as well.

Thanks for the reply. I have a JDM ecu. I'll check what you suggest. I had reset the ecu to clear codes and the engine light came up again. I expected it to be code 16 again but to my surprise it was code 6 - coolant temp sensor - wtf...the only thing I can think of was I hadn't bled the cooling system after I took off the IACV. But I have now bled the system and reset the ecu and will see what happens.

coolant will not trigger code 6


are you runing a convertion harness

No conversion harness...I should have said the whole car is stock jdm sir2. Having a look at your page for code 6...a faulty sensor may be the culprit...but it may just some freak one off thing.