Reading Volvo 850 1996 Non-Turbo Codes

[xanthefin]

Hi there,

I’ve got the OBD-II app and the ELM device that was recommended (same model others suggested). I’ve successfully reset the old codes as well as the service light, so progress is being made!

Now, I’d like to understand the best way to use the app and device to check engine or transmission or any codes. Since my car is a Volvo 850 (1996), I believe it uses the Motronic M4.3 system. Could you guide me on how to configure the app and connect properly for this specific system? Any tips or steps would be greatly appreciated!

Is it possible to read the engine and transmission codes using the OBD-II app and the ELM device I have? Or is my car’s system (Volvo 850, 1996, Motronic M4.3) incompatible with this setup?

If I can’t read the codes with this combination, do I need a different device or tool to access them? Any recommendations would be helpful!

Thanks in advance!

Hi, App doesnt support M4.3 Engine ECU sorry. You need leave that option out.

On 850 models you can see information (Fault Codes, Live Data) / Read Codes / *Trigger Device testings and *Program parameters via OBDII from these ECUs

Motronic M4.4*
MSA15.7*
AW50-42 (Automatic Gearbox)*
ABS*
SRS (Airbag)
COMBI (VDO dashboard)*
Front Electric Seats*
IMMO*



Transmission it does as you seen from Summary view its there readen and no codes. So to read fault codes is from Service >> Scan (and select ECUs you have on car | Selection viewavle ECUs Default is "All" and then some models and years of Volvos but example next update there will be too 850 Series selection to limit out 70 series ECUs like VGLA, ECC etc..) it says these days below it if ECU had codes or no codes in same view. Example in Screenshots ECU 58 (SRS) -- Module information -- and next there below is "ECU: 58 No fault codes reported".
Then next ECU 6E (AW 50-42) [This is Transmission] -- and below again ECU: 6E No fault codes reported.. So gearbox doesnt have fault codes.



Only old - not anymore produced for decades - Volvo System Tester which Volvo used internally and their dealerships do in full length support (additionally to ex. led light way to read codes via OBDII port pin #3 it only supports Live Data) M4.3 as it uses older Volvo diagnostics system protocol but it has a side protocol which is just led light and switch system to read it which older 850 models ( pre 96 ) had own diagnostic box under bonnet to read codes.


The system you looking for costs anything between 300 EUR to here if you even manage find one from market used.



So far only in plans is write support for Fenix 5.2 ECM in App with special ways in future but not yet in to do list. It might use same commands as Motronic M4.3 but i cant confirm as i dont own that ECM.

Hi,

I’m exploring my options here and wondering if flashing my system to Motronic M4.4 would be a good idea. I’d like to avoid spending $3,000 on a professional reader, so I’m looking for cost-effective alternatives.

Today, I managed to read and scan codes using the OBD-II app and device again. However, I noticed some limitations:

- I can’t access live OBD-II data, but I can view live data when using the COMBI option.
- I performed tests using the OBD-II connection. For example, I tested the ABS and heard the valves activating in the car, which seems to confirm the connection is functional for tests.
- When I select OBD-II and press "scan codes," it seems to scan for issues but doesn’t return any errors. Is it actually scanning for codes, or could it be missing something?

Given these observations, what are my choices moving forward? Should I stick with my current setup, consider flashing to M4.4, or look into alternative tools? Any advice or recommendations would be greatly appreciated.

Only OBDII Standard connectivity comes in your car is from Transmission (no ECM responding -- App can show multiple ECUs if they respond to OBDII Standard requests which on example models with M4.4 and Transmission does) which i actually now forgot did App actually show "No codes" from OBDII standard codes (aka Pxxx style codes) which is good point i need add that message as i think i forgot that totally.
OBDII Standard i never suggest anyone to follow fully in diagnostics in Volvos to diagnose due how much misleading them can be (i dont show description text for them due it -- translation can change manufacturer -- model year -- engine etc..). But it scans and shows Pxxx code itself if they exist yes from OBDII Standard side.

as misha said led reader is mostly the way for these ECUs which based on that Volvo Diagnostic level as here example for M4.3 ECM.

[BeerDeer]

Hi, App doesnt support M4.3 Engine ECU sorry. You need leave that option out.

On 850 models you can see information (Fault Codes, Live Data) / Read Codes / *Trigger Device testings and *Program parameters via OBDII from these ECUs

Motronic M4.4*
MSA15.7*
AW50-42 (Automatic Gearbox)*
ABS*
SRS (Airbag)
COMBI (VDO dashboard)*
Front Electric Seats*
IMMO*



Transmission it does as you seen from Summary view its there readen and no codes. So to read fault codes is from Service >> Scan (and select ECUs you have on car | Selection viewavle ECUs Default is "All" and then some models and years of Volvos but example next update there will be too 850 Series selection to limit out 70 series ECUs like VGLA, ECC etc..) it says these days below it if ECU had codes or no codes in same view. Example in Screenshots ECU 58 (SRS) -- Module information -- and next there below is "ECU: 58 No fault codes reported".
Then next ECU 6E (AW 50-42) [This is Transmission] -- and below again ECU: 6E No fault codes reported.. So gearbox doesnt have fault codes.



Only old - not anymore produced for decades - Volvo System Tester which Volvo used internally and their dealerships do in full length support (additionally to ex. led light way to read codes via OBDII port pin #3 it only supports Live Data) M4.3 as it uses older Volvo diagnostics system protocol but it has a side protocol which is just led light and switch system to read it which older 850 models ( pre 96 ) had own diagnostic box under bonnet to read codes.


The system you looking for costs anything between 300 EUR to here if you even manage find one from market used.



So far only in plans is write support for Fenix 5.2 ECM in App with special ways in future but not yet in to do list. It might use same commands as Motronic M4.3 but i cant confirm as i dont own that ECM.

Hi,

I’m exploring my options here and wondering if flashing my system to Motronic M4.4 would be a good idea. I’d like to avoid spending $3,000 on a professional reader, so I’m looking for cost-effective alternatives.

Today, I managed to read and scan codes using the OBD-II app and device again. However, I noticed some limitations:

- I can’t access live OBD-II data, but I can view live data when using the COMBI option.
- I performed tests using the OBD-II connection. For example, I tested the ABS and heard the valves activating in the car, which seems to confirm the connection is functional for tests.
- When I select OBD-II and press "scan codes," it seems to scan for issues but doesn’t return any errors. Is it actually scanning for codes, or could it be missing something?

Given these observations, what are my choices moving forward? Should I stick with my current setup, consider flashing to M4.4, or look into alternative tools? Any advice or recommendations would be greatly appreciated.

Only OBDII Standard connectivity comes in your car is from Transmission (no ECM responding -- App can show multiple ECUs if they respond to OBDII Standard requests which on example models with M4.4 and Transmission does) which i actually now forgot did App actually show "No codes" from OBDII standard codes (aka Pxxx style codes) which is good point i need add that message as i think i forgot that totally.
OBDII Standard i never suggest anyone to follow fully in diagnostics in Volvos to diagnose due how much misleading them can be (i dont show description text for them due it -- translation can change manufacturer -- model year -- engine etc..). But it scans and shows Pxxx code itself if they exist yes from OBDII Standard side.

as misha said led reader is mostly the way for these ECUs which based on that Volvo Diagnostic level as here example for M4.3 ECM.

So, just to confirm my understanding:

So I need to use the LED setup to read engine codes, but I can use the app to read everything else except engine codes (Tranmission, AC, ABS...). Is that correct? I just want to make sure I’m interpreting this correctly before proceeding.

Thanks for clarifying!

[BeerDeer]

You can make your own flash code reader with a few wires,led and resistor for reading m4.3,Jetronic & Siemens ecu...along with ECC.
850 obdII app can be used for the rest of modules in the car.

Hi,

I’m trying to figure out how to read the transmission codes and ABS codes. Can you tell me which pins are used for these? Will the app work for reading them, or do I need to use a different method?

I found some pictures online:

Pin 3: Is this for the ECU? Does ECU mean all engine codes?
Pin 6: Is this for the ECC (Electronic Climate Control)?

I also read that:

Pin 7 could be for the Transmission Control Module (TCM), and
Pin 1 might also be for the TCM.

Can you confirm if this is accurate? I want to be sure before proceeding.

Thank you so much for your help!

[xanthefin]

Hi,

I’m exploring my options here and wondering if flashing my system to Motronic M4.4 would be a good idea. I’d like to avoid spending $3,000 on a professional reader, so I’m looking for cost-effective alternatives.

Today, I managed to read and scan codes using the OBD-II app and device again. However, I noticed some limitations:

- I can’t access live OBD-II data, but I can view live data when using the COMBI option.
- I performed tests using the OBD-II connection. For example, I tested the ABS and heard the valves activating in the car, which seems to confirm the connection is functional for tests.
- When I select OBD-II and press "scan codes," it seems to scan for issues but doesn’t return any errors. Is it actually scanning for codes, or could it be missing something?

Given these observations, what are my choices moving forward? Should I stick with my current setup, consider flashing to M4.4, or look into alternative tools? Any advice or recommendations would be greatly appreciated.

Only OBDII Standard connectivity comes in your car is from Transmission (no ECM responding -- App can show multiple ECUs if they respond to OBDII Standard requests which on example models with M4.4 and Transmission does) which i actually now forgot did App actually show "No codes" from OBDII standard codes (aka Pxxx style codes) which is good point i need add that message as i think i forgot that totally.
OBDII Standard i never suggest anyone to follow fully in diagnostics in Volvos to diagnose due how much misleading them can be (i dont show description text for them due it -- translation can change manufacturer -- model year -- engine etc..). But it scans and shows Pxxx code itself if they exist yes from OBDII Standard side.

as misha said led reader is mostly the way for these ECUs which based on that Volvo Diagnostic level as here example for M4.3 ECM.

So, just to confirm my understanding:

So I need to use the LED setup to read engine codes, but I can use the app to read everything else except engine codes (Tranmission, AC, ABS...). Is that correct? I just want to make sure I’m interpreting this correctly before proceeding.

Thanks for clarifying!

Yes but i didnt list AC for you.

These ECUs on this list on 850 series models are not behind OBDII port for ELM interface to be readen.
-Motronic M4.3
-MFI system (LH-jetronic 3.2 & EZ129K)
-Fenix 5.2
-ECC(A/C)
-Cruise Control


All others which are not listed ECUs App can read and clear fault codes on 850 models.



For below later your question.. ABS and TCM aka Gearbox aka Transmission code readen.. what you have in mind as you have readen them in screenshots?
Pin #3 is ECM (ECM aka Engine Control Module - I call in the car all electronic modules as ECUs as its more used these days call them all as Electronic Control Unit)


Red is circled ABS and its two fault codes and their descriptions
Blue is TCM / Gearbox / Transmission and it says No Fault codes reported.. so it doesnt have any fault codes.
AW50-42 is type of Gearbox what was used on 850 and 70 series and Volvo didnt yet these days used term "TCM" which why its named like how Volvo did on their own Service Tool as well. Since 99 year model 70 series Volvo did upgrade their Service tools to call AW50-42 aka Transmission as TCM so thats why it changes in App too for those models as "TCM".

[BeerDeer]

Only OBDII Standard connectivity comes in your car is from Transmission (no ECM responding -- App can show multiple ECUs if they respond to OBDII Standard requests which on example models with M4.4 and Transmission does) which i actually now forgot did App actually show "No codes" from OBDII standard codes (aka Pxxx style codes) which is good point i need add that message as i think i forgot that totally.
OBDII Standard i never suggest anyone to follow fully in diagnostics in Volvos to diagnose due how much misleading them can be (i dont show description text for them due it -- translation can change manufacturer -- model year -- engine etc..). But it scans and shows Pxxx code itself if they exist yes from OBDII Standard side.

as misha said led reader is mostly the way for these ECUs which based on that Volvo Diagnostic level as here example for M4.3 ECM.

So, just to confirm my understanding:

So I need to use the LED setup to read engine codes, but I can use the app to read everything else except engine codes (Tranmission, AC, ABS...). Is that correct? I just want to make sure I’m interpreting this correctly before proceeding.

Thanks for clarifying!

Yes but i didnt list AC for you.

These ECUs on this list on 850 series models are not behind OBDII port for ELM interface to be readen.
-Motronic M4.3
-MFI system (LH-jetronic 3.2 & EZ129K)
-Fenix 5.2
-ECC(A/C)
-Cruise Control


All others which are not listed ECUs App can read and clear fault codes on 850 models.



For below later your question.. ABS and TCM aka Gearbox aka Transmission code readen.. what you have in mind as you have readen them in screenshots?
Pin #3 is ECM (ECM aka Engine Control Module - I call in the car all electronic modules as ECUs as its more used these days call them all as Electronic Control Unit)


Red is circled ABS and its two fault codes and their descriptions
Blue is TCM / Gearbox / Transmission and it says No Fault codes reported.. so it doesnt have any fault codes.
AW50-42 is type of Gearbox what was used on 850 and 70 series and Volvo didnt yet these days used term "TCM" which why its named like how Volvo did on their own Service Tool as well.

Appsho2t.jpg

Here’s an improved version of your message:

Thanks for the help! I was able to clear the codes, and the fuel code is now gone—only the ABS code remains, which I’ll check out later. I’ve decided to keep the app and device since they’re useful for reading most systems.

However, for engine codes, it seems the only option is using the DIY LED light method (as shown in the attached image), right? That’s my top priority right now, especially since I’m dealing with a clogged PCV system and had previous misfire issues.

Let me know if I’m on the right track. Thanks again!

(Check attached picture)

[xanthefin]

* pin 1 -- EZ 116K Ignition (for 900 and S90/V90)
* pin 3 -- Motronic 4.3 (for Volvo 850 T5?)
* pin 3 -- Fenix 5.2 (for Volvo 10 Valve 850 and ?70)
* pin 3 -- Jetronic LH 2.4 (for Volvo 900 and S90/V90)
* pin 6 -- Climate Control (for Volvo 850)
* pin 12 -- ABS (for Volvo 900 and S90/V90)
* pin 13 -- Cruise Control (for Volvo 850 and other models)


Yes picture lights are correct.. the thing is just switch grounds connection momentarily to give signal and then ECU will return with GND so LED lights up and how ECU pulses the GND in return which you see as LED blinking.

P.S. I suggest not Grounding Pin #7 as its shared connection.
P.S.S Sorry of confusion as i didnt first catch that AW50-42 name as what it meant was lost in translation previously.

[BeerDeer]

* pin 1 -- EZ 116K Ignition (for 900 and S90/V90)
* pin 3 -- Motronic 4.3 (for Volvo 850 T5?)
* pin 3 -- Fenix 5.2 (for Volvo 10 Valve 850 and ?70)
* pin 3 -- Jetronic LH 2.4 (for Volvo 900 and S90/V90)
* pin 6 -- Climate Control (for Volvo 850)
* pin 12 -- ABS (for Volvo 900 and S90/V90)
* pin 13 -- Cruise Control (for Volvo 850 and other models)


Yes picture lights are correct.. the thing is just switch grounds connection momentarily to give signal and then ECU will return with GND so LED lights up and how ECU pulses the GND in return which you see as LED blinking.

P.S. I suggest not Grounding Pin #7 as its shared connection.
P.S.S Sorry of confusion as i didnt first catch that AW50-42 name as what it meant was lost in translation previously.

Thank you so much.

Pin #7? You mean Pin #5? but everyone says to do it like that;

https://www.volvoforums.org.uk/showthread.php?t=83895

I don't want to burn my ECU..

[xanthefin]

* pin 1 -- EZ 116K Ignition (for 900 and S90/V90)
* pin 3 -- Motronic 4.3 (for Volvo 850 T5?)
* pin 3 -- Fenix 5.2 (for Volvo 10 Valve 850 and ?70)
* pin 3 -- Jetronic LH 2.4 (for Volvo 900 and S90/V90)
* pin 6 -- Climate Control (for Volvo 850)
* pin 12 -- ABS (for Volvo 900 and S90/V90)
* pin 13 -- Cruise Control (for Volvo 850 and other models)


Yes picture lights are correct.. the thing is just switch grounds connection momentarily to give signal and then ECU will return with GND so LED lights up and how ECU pulses the GND in return which you see as LED blinking.

P.S. I suggest not Grounding Pin #7 as its shared connection.
P.S.S Sorry of confusion as i didnt first catch that AW50-42 name as what it meant was lost in translation previously.

Thank you so much.

Pin #7? You mean Pin #5? but everyone says to do it like that;

https://www.volvoforums.org.uk/showthread.php?t=83895

I don't want to burn my ECU..

Yes use Pin # 5 for Ground for your led flasher diagnostic tester.

I did mean shortly not put the wire in Pin # 7 at all like you thought in previous messages once as an option (not to push that pin to ground i meant as there is communication between modules too)
This message i mean: Pin 7 could be for the Transmission Control Module (TCM)


ECUs has some level protection against shorts and accidental +12V feed but i feel like not to test them unnecessarily.

[BeerDeer]

* pin 1 -- EZ 116K Ignition (for 900 and S90/V90)
* pin 3 -- Motronic 4.3 (for Volvo 850 T5?)
* pin 3 -- Fenix 5.2 (for Volvo 10 Valve 850 and ?70)
* pin 3 -- Jetronic LH 2.4 (for Volvo 900 and S90/V90)
* pin 6 -- Climate Control (for Volvo 850)
* pin 12 -- ABS (for Volvo 900 and S90/V90)
* pin 13 -- Cruise Control (for Volvo 850 and other models)


Yes picture lights are correct.. the thing is just switch grounds connection momentarily to give signal and then ECU will return with GND so LED lights up and how ECU pulses the GND in return which you see as LED blinking.

P.S. I suggest not Grounding Pin #7 as its shared connection.
P.S.S Sorry of confusion as i didnt first catch that AW50-42 name as what it meant was lost in translation previously.

Thank you so much.

Pin #7? You mean Pin #5? but everyone says to do it like that;

https://www.volvoforums.org.uk/showthread.php?t=83895

I don't want to burn my ECU..

Yes use Pin # 5 for Ground for your led flasher diagnostic tester.

I did mean shortly not put the wire in Pin # 7 at all like you thought in previous messages once as an option (not to push that pin to ground i meant as there is communication between modules too)
This message i mean: Pin 7 could be for the Transmission Control Module (TCM)


ECUs has some level protection against shorts and accidental +12V feed but i feel like not to test them unnecessarily.

Thank you for your kindness. I will report back with any errors!