How to Read a Code on NPR and NQR Without a Computer 

Thanks that's the kind of how to videos I like! Keep up the great work man!

thanks Thomas for the video ... i have the same problem on a canter 3.0 (error 11) ... could you tell me what it refers to?

Thanks Thomas...Great info...I will try this out.

Hello: i have a 2005 isuzu npr 4hk1 automatic. I believe I have pins missing in my OBD2 port and when I cross 4*11 all i get is a constant steady trans flashing light no breaks in between the flashes.Do you have another way via another set of pins to cross?? also it isnt as steady and slow as youres it flashes fast and contant!

Well Said!! Thank You!!!!!!

Hey Thomas hows it going ? I hope good. Question I am having trouble with my 2012 npr. It has a glow plug controller and dpf filter. I replaced the controller and cleaned out the filter myself. I used gasoline at first and pressure wash the filter afterward. Now the DEF light is on and some sensor with two hoses going in/out of it. I replaced it but not the def since it clean and full. Problem I am having it's not letting me clear the codes. Still stuck at 5pmh

Thanks Thomas.

I have a 2000 npr 4.8...the check trans light flashes after warm and the at/temp light is on all the time...even when cold... and has all the power in the world when it is cold but after it warms up it has a hard time climbing Hills... basically loss of power... Which later on develops into acting like a gas motor that is skipping... pull it over shut it off for a few minutes start it back up it runs fine again... the previous owner changed the transmission in it... in the truck only has 138,000 miles on it

Great video.

Thanks Thomas!

In your amazon link for a Heavy Duty Code Reader, the reader is for 24v, can you recommend a reader for a Isuzu 2003 NPR HD 4HE1? Thank you,. John

Thank you and I want to know more about any code

My 2008 NPR gas would not crank but has a good battery and no 12Volts at the solenoid when the key was in the crank position. I found that simply removing and replacing fuse 22 in the dash would allow it to crank and start. This has happened twice recently. Do you know what is wrong?

2001 w5500 glow plug light does not come on at all and it had difficult start on cold mornings, any suggestions?

Great video 👌. Need some help troubleshooting non starting 2005 npr that's has power. Thanks

Hi Thomas, I'm thinking about buying a 2007 isuzu npr 5.2, engine and transmission have been replaced but the dash has aa flashing check trans light while the truck is on and while driving. Owner said it has been doing that since transmission was replaced. No check engine light but I tried connecting my obd scanner to check for codes but it will not connect to the truck for some reason. Any idea what might be the problem here?

I have a 98 NPR it has been is 4 shops the Last was a Isuzu dealer they can not fix my problem of the trans. It started when we did some welding on the truck. afterward it would not shift out of 3rd gear into 4 unless you let up off the accelerator. they told me they did not know how to work on a truck that was this old. Any suggestions ? We need this truck . thanks in advance Andrew.

Aye i have a 2003 isuzu npr, but identification lights, 5 ones on the cab are not turning on, but the rest of the lights are. Do you know if its a fuse or what can it be. ?

Hi there I have a 06 npr that sometimes it does not accelerate on drive or reverse but it does accelerate on park or neutral And sometimes the truck works fine and runs strong The truck was park for two years everything was working fine I drove the truck about 100 miles and now is giving me that problem I have change the filter it had a full thank when I got it I haven’t put any diesel on the tank

hello brain I have a question if you can help. I have a 06 GMC w4500 5.2L isuzu engine. Will start and idle but no response when accel pedal pressed. I checked signal on acc pedal and it is respnding with no glitches. I was able to pull a Code P0091 Fuel Pressure Regulator 1 Control Circuit Low. I wanted to ask where is the Reg. located. It seems like a Limp issue. Any help ?

Hey Thomas I have a 2001 isuzu npr hd. 4.8l diesel. I am getting codes 19 , 21 ,and 35 can you please tell me what these stand for

Where is tcm located an 2012 npr. On dash the gear logo flashes. My transmission dont shift. Stays in one gear. Manual says its tcm. Any suggestions? Thanks

Hi . I have a 1998 npr diesel , seems doesn’t have obd connector , engine works bad rough sound when accelerating and doesn’t have power. What should I do?

Hi sir. How about if i want to check the flash code for check engine?

Will this same code reading work even on a gas engine I've got a box truck NPR gas-powered and it constantly keeps going into limp mode so I'm thinking it has to do with the computer because the throttle body has already been replaced replacing the throttle body did fix it but only for a couple and then it started going into limp mode again

Hi Brian, how are you? Thank you for your video and I have code 11 first and then 22 on my 2007 GMC w4500. Can you help on how to resolve these issues? Thank you in advance. T.

Hi Thomas My truck isuzu npr 250 alternator light not coming on dashboard and not starting it just cranks hiw can i rectify it thanks

what if your truck is a standard truck what would be blinking for the codes ?

2004 FRR, my mechanics CANT pull my CEL codes, due to the trucks plug-in is damaged. I take it to Isuzu and the are able to pull codes with their reader"using the cigarette lighter" process. both of my mechanics have those expensive code readers, any idea? isuzu charges to much just to pull codes. I would like to have my personal mechanics to it. On a side note, My truck 400k miles drives strong other than the occasional power loss at any speed and sometimes it will stall. My mechanic advised me to pop off the fuse cover, "wiggle" the relays on the dash and it always starts right up and drives normal for most of the day. TIA

good info. thank you.

Hi Thomas, I have a question on my 1996 isuzu pnr I'm confused with the ttrans light, light is blinking twice pause and blinking 5 times what's that's mean ? I hope can help me to figure out, thanks

Hey Thomas I'm not getting no engine check light also no power at the diagnostic socket can you help..I have the 2000 isuzu npr66.

Can I get service manual of isuzu 4hl1 2006 model. And wiring diagram

Hi, i have Isuzu NPR 2004(2005). With 2 errors, 1(long) and 9 flashes 3 times and 4 flash 1 (long). (19 and 41 error code). Can you help me with it? Thx!

I am getting a code P1904 on my 05 Isuzu diesel. Any idea on help to fix it?

Here I have 2006 Isuzu forward without an obd connector. How to retrieve codes because it has a check engine light and no power. Thanks

Hey Thomas, thanks for this video, really helpful. To the point and clear. I have a check transmission lights blinking and my transmission isnt shifting above 2nd gear on D. Its not engaging in reverse as well. Ive tried the car computer reader but havnt had much luck. From a bit of Googling, this maybe a master solenoid or a fuse. Can you advise whats the codes for npr 250 2004 automatic..

have any videos of isuzu npr crank shaft jammed?

Do you know of this will work on the 2007 mitsubisgi fuso also?

2005 NPR with 5.2 diesel/ Following your procedure what does a 4 flash code mean?

I know this is a older video. But I can’t find out what the codes mean. Can you list the transmission codes or seen me a link. Appreciate the help. I looked everywhere.

Thanks for all

wondering why when pulling codes manually on 2005 isuzu npr pins 4 and 11 the trans light just flashes non stop with no pause to give you the 2 digit code.

Bravo......got the pins......what are the pins connect to........cheers

Hello thomas After i get the codes on my npr 2002 where i can get the codes result

there is not flash to let you know its going to flash. 2 flashes one right after the next. first flash is 1 , quickly followed by second flash which is 1 also. That is probably to signify that its communicating with ECM. If any codes would be after that. There is a pause between codes longer that the pause between code digits.

Hi I have a 2003 NQR. I just replaced the transmission with a factory re maned Allison trans and a new radiator to make sure trans cooler is new and flexible trans cooler lines and rear hard trans lines flushed the other lines out that are still good and had actually been replaced before the old trans was slipping. During the whole process we had unhooked the battery. After everything is back together and filled radiator with coolent and transmission with about 4.5 quarts of Allison trans fluid I try to start the truck so I can let it run and get air out of radiator if any and get trans pumping fluid and check/add fluid and get up to temp. Lights come on and check trans light comes on one time and shuts off. Won’t turn over or even make clicking sounds like it is trying. I tried resetting the battery reset that is on the battery and also checked the starter fuse. All good but no dice. Any advice?

I got a 99 Isuzu npr how do I pull codes if it doesn't have obd2 comnecter

I have a 2002 NPR...350 gasoline. When I turn on right blinker...it makes a loud humming noise...blinker won’t work and it has tripped on three service lights on the dash. Radio fuse removed and negative battery ground disconnected did not clear dash lights. Anyone got a suggestion?

Does this procedure apply to 2007 isuzu fvr?

Is it the same for gas and diesel?

Any suggestions I would extremely appreciate it

My truck flashes 7 times 13 times in a row. Waited for pause. So not sure if code 7 or 77? Thanks

I have a 99 Isuzu NPR Gas, Was on the way to do a delivery and noticed the service engine light came on. Shut er down to make the delivery. When I tried to restart the truck All I got was a crank with a no start. Since then I have been having to bypass the fuel pump relay to get it to start after about 6 cranks it reluctantly starts and runs fine till I shut it down. Any thoughts ? I will try the code video you posted above. Thanks in advance. I'v had this truck to several different shops with no success. Nobody around here can help me. The tow bills are killing me!

I have a 06 semi NQR truck always go into dpd limp mode , when I stop an regen Ok, started drive; it come back about hour time

Where is that fuse for the tuning lights?

Getting code 19 and either 31 or 41. 4 slow blinks than 1 quick. Where do I find what these mean?

I fix the misfire and I’m still getting one long pause and nine flashes three times in a row and then it just keep repeating that I took a video of that

What if the OBD2 is not working what can I do I want to diagnose the car

What does this mean on a 2003 gmc npr

Where can i find the code 11 on isuzu..and how ti fix it..thanks

What if the plug doesn't have a pin in port 11? 2013 NPR300

Does anyone know where the OBD2 port is on a GMC W3500?

does this work for 2018 NPR HD 5.2 L?

Hey, I have a 2006 NPR and once the CEL comes on it'll go into limp mode (no power and only about 10mph) does anyone happen to know what the problem mite be? Or do I need to get the codes? Just wondering if anyone has ran into this issue and knows the solution. Thanks!

Is it the same on a 1997 NPR?

Hey, great video! I did the jumper and get two flashes followed by four short flashes. I think that means code 24? Can you tell me what this means? Truck has been randomly flashing the check trans light. When the check trans light comes on the transmission wont engage, and will only drive in 2 or 1.

Anyone know where i can get some fuel injectors for a 2003 isuzu npr diesel?

Can you help on an 2002 Isuzu FRR? Sevice engine light flashes one time every three seconds. It’s done this every since I bought the truck. No one has been able to pull codes with a scanner or communicate with the ecm. The scanner I have will communicate with ecm, to see live data, but can’t read or clear codes, or read abs module. Will a cheap Actron scanner read generic code and ABS? Thank you for any help or advise.

Do you have the code list?

Hey Thomas! I have an Isuzu NPR 4HJ1 Engine. The problem is i had to put the idle switch on a high to make the truck run because if i lower it to a normal idling or rpm, it chokes/coughs and.eventually if i am on full stop, the engine dies. But if i keep on switching to high idling it is not fuel efficient, right? What do you think is/are the problems that might contribute to it? Thanks!

What about how to get abs codes?

I just tried this on an 06 NPR and it didn't work?! the fault it has is the idle speed knob on the dash is not working, need to be able to increase idle speed for the PTO

Isuzu npr truck 2009 blinking engine light any solution

thanks for sharing your knowledge. I have a Nissan UD 1300 SERIES, Diesel, 2007, with a 450-43LE transmission, I CAN'T pull codes out of it! the OBD connector has only THREE wires in it and about four loose separated wires as follows: purple white E tag, black wire with another wire light blue with with yellow traces attached A tag, sea water blue color wire B tag, Red with blue traces wire with ILL tag, and electric blue wire with IGN tag ! please let me know if You could pull codes out of it! thank You very much! for your cooperation! God bless You!

I have 2006 nqr diesel. The dash indicator light for reverse comes on when i hit the brake pedal and the check trans light flashes every now and again. Any ideas ?

Hello i have a 2006 And I'm having transmission problems when my headlights are turned on or my blinker is being used the truck won't shift out of whatever gear it's in and the check trans light comes on. To get going again i simply turn the the truck off as well as the headliggt switch and turn the truck back on and im back to normal. Very frustrating when i get an evening service call. also I should note that my abs light is always on and my dashlights dont work any longer and i have checked all the fuses in and behind the glove and everything is as it should be.....any thoughts?

My Isuzu NPR is stocked on reverse and won't transmit to other forward gears

2005 lefthand drive smoother automatic transmission won't move whenever inge in drive are rev

Side question: I bought my 2004 npr with 98k, i have 120k on it now i have never done transmission oil change on this truck what should i do? is it late for a transmission oil change?

hi, where can i get the code list

i have 2006 w3500 5.2 which is the same as a npr ,im getting the long pause of a check trans light and afetr 9 flashes which would be code 9? and the check eng light on for a p0302

Thomas, my check transmission light on 2005 NPR comes on and flashes 9 times. Is that 19? Truck drives fine but don't know why check transmission light flashes while driving. Thanks

Where could I look up the codes?

Where would i get a list of fault codes

Great info 💪🏻💪🏻💪🏻

I willLet you know what I find I am waiting for my snap on dealer to get me a medium duty scan tool but any help from your end would be awesome thank you

I'm having a problem with my 2005 npr it's a fuel issue wondered if you have much experience with this issue with 2005 npr ?

What if it's a 1994 gas npr?

Hey man I clicked on ur name and I didn't see a video for for code 11 ? Please write back

Thanks I never new this. I think I’m get code 77 and 99 but I cant find what these mean

Isuzu NPR 2005 machine please decode flash codes 19 and 41

My engine 4hg1 efi problem can you help me

Will this be the same on Nissan UD 1300?

Hi can you help me with a code 7 what’a is

Whats a code 19 on a 2007 NRR

I have an 06 Isuzu 5.2 always going into limp mode.. only that's like 25 miles an hour..

My NPR HAS NO OBD2 PLUG HOW DO THE JUMPER WIRE

How to isuzu 2005 4hl1 diagnostic

Wow, where did you get this info? Does that trick work with OBD1 models?