ABS light on. Can't get codes

oldtimeracer · Jul 12, 2024

I have a 2004 Mustang GT with auto. The ABS light is on. I have a Launch code reader. I can't get codes for the ABS. it says not equipped or on connection. Were do I start looking? I checked the fuses they are good. The brakes work fine. The light was on when I bought the car. The power steering pump was bad, didn't put out enough pressure. I replaced the front calipers. The outside s were pitted the inside were fine. I also replaced a pads. Brake hoses look good. The wheel sensors look good as to the tone rings. Don't know if the sensor work correctly or not. I want to check all the electrical connections grounds for the PCM and ECU . Not sure were they are located. Just need to get the reader to work. It reads OBD2 ABS and SRS.

Noobz347 · Jul 13, 2024

Mustang5L5 · Jul 13, 2024

Try another code reader. The main issue with those bidirectional Chinese scan tools is they tend to have communication issues. It’s not unheard for them to simply not communicate, compared to something like an Autel.

I have an Xtools D7 and it will see the ABS module and any DTCs stored on my ‘00.

If you have a laptop you can also install ForScan and just grab a obd2 to usb interface. Will lets you see modules and run basic service procedures like ABS test functions. In theory a good scan tool should also allow you to do this as well.

The ABS on these cars is pretty simple. 4 wheels speed sensors and hubs, and a central Brain. Most ABS codes will either be a sensor issue, or an internal issue with the ABS module itself. You can check the sensors (without codes) by unplugging each sensor and measuring resistance. A bad one will be open.

Edit: you didn’t say what model Launch scan tool you have. Some of the lower trims won’t read modules and just do OBD2 data.

oldtimeracer · Jul 13, 2024

Mustang5L5 said:
Try another code reader. The main issue with those bidirectional Chinese scan tools is they tend to have communication issues. It’s not unheard for them to simply not communicate, compared to something like an Autel.

I have an Xtools D7 and it will see the ABS module and any DTCs stored on my ‘00.

If you have a laptop you can also install ForScan and just grab a obd2 to usb interface. Will lets you see modules and run basic service procedures like ABS test functions. In theory a good scan tool should also allow you to do this as well.

The ABS on these cars is pretty simple. 4 wheels speed sensors and hubs, and a central Brain. Most ABS codes will either be a sensor issue, or an internal issue with the ABS module itself. You can check the sensors (without codes) by unplugging each sensor and measuring resistance. A bad one will be open.

Edit: you didn’t say what model Launch scan tool you have. Some of the lower trims won’t read modules and just do OBD2 data.

I will try to get codes off My 2011 Chevy Silverado. The code reader is brand new. there are a lot of videos about this reader all good. so if it works on my other vehicle then it should be good to go. Thanks

oldtimeracer · Jul 14, 2024

The reader works perfectly on t=my 2011 Chevy Silverado So the reader is not the problem. What would keep the reader from seeing that codes on the ABS system? It sees the engine codes. So the OBD plug is working ok. I guess it could be one of the pins? Could it be the ECU not connecting to the ABS system?

Noobz347 · Jul 14, 2024

oldtimeracer said:
The reader works perfectly on t=my 2011 Chevy Silverado So the reader is not the problem.

This is not proof that it will pull codes from your GT. If you have the opportunity, try a different reader just so you're not chasing ghosts.

oldtimeracer said:
Could it be the ECU not connecting to the ABS system?

This is a possibility. A broken connection would certainly trip the light.

I've seen instances where folks reseated the main ECU connector and cleared up stuff like this too.

Mcmahst · Jul 14, 2024

You might try running over to AutoZone and having them use their code reader. I happen to know that their code readers work on ABS systems for Ford. Don’t ask me how I know: it’s just another possible solution.

allee_v8 · Aug 20, 2024

Does any one have The wiring diagram From the p c m to the transmission for the pressure controls sylenoid? I'm having a similar issue but my hynes manuals Don't have the wiring for it

oldtimeracer · Aug 27, 2024

I have a 2004 Mustang GT 4.6 auto. Bought it used. When I connect it to ECU 16 pin port. It shows it isn’t connected to ABS. Also most of the protocols fail. The car runs good. The reader doesn’t see the VIN number. Could it be the car has a ECU out of another car? If so can I get it flashed to get ABS back working and so I can use my reader to diagnose the car in the future? I only get one code now for the intake air temp? Thanks

RaggedGT · Aug 27, 2024

Do you have a scanner capable of reading ABS?

oldtimeracer · Aug 27, 2024

yes and it works on my other car

RaggedGT · Aug 28, 2024

Is this the style abs block you have?-
If so-maybe start with that connector, here’s a quick pin out I found-

I’d check for power-continuity etc,maybe there is a broken wire in the harness?

Noobz347 · Aug 28, 2024

oldtimeracer said:
I have a 2004 Mustang GT 4.6 auto. Bought it used. When I connect it to ECU 16 pin port. It shows it isn’t connected to ABS. Also most of the protocols fail. The car runs good. The reader doesn’t see the VIN number. Could it be the car has a ECU out of another car? If so can I get it flashed to get ABS back working and so I can use my reader to diagnose the car in the future? I only get one code now for the intake air temp? Thanks

What code did you get, exactly?

ABS light on. Can't get codes

oldtimeracer

New Member

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Mustang5L5

That is…until I whipped out my Bissell

oldtimeracer

New Member

oldtimeracer

New Member

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Mcmahst

allee_v8

New Member

oldtimeracer

New Member

RaggedGT

Been here over a DECADE and still no CT

oldtimeracer

New Member

RaggedGT

Been here over a DECADE and still no CT

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor

Similar threads

ABS light on. Can't get codes

New Member

Stangnet Facilities Maint Tech... Er... Janitor

That is…until I whipped out my Bissell

New Member

New Member

Stangnet Facilities Maint Tech... Er... Janitor

New Member

New Member

Been here over a DECADE and still no CT

New Member

Been here over a DECADE and still no CT

Stangnet Facilities Maint Tech... Er... Janitor

Similar threads

Privacy & Transparency

Privacy & Transparency