My pcm is not communicating with abs car is in limp mode can't get it resolved

2005 year, BMW (secret) 325i, engine , inline 6cyl. the E46, engine type. M54B22 2.17liters.????
the USA engine or Europe or what?
NO country told wow that is a hard nut question.
get it serviced in a real shop ! end.
no real evidence told, only
what means limp, ASE defined, USA>? or you speak that in some untold why ,what does limp mean to you.
ASE defines that is what you get in EFI PCM limphome mode. or CEL lamp stuck on.

and...
limp home, happens on many things in car.
ECU/PCM limp for engine , failures DTC gross errors, why not scan the PCm first.? SCAN it with real BMW scan tool to see all BMW codes (DTC)
transmission limp mode. happen too, again scan it.
if in use the scan tool OBD2 fits to the 16pin USA scan port called DLC. and a good tool sees all P0xxx codes and P1xxx p2 ,p3 up BMW factory codes. DTC, using the wrong tool is working blind
no modern car can be fixed now lacking a tool of such kind
drive line, airbags, ABS, and more. lots more.
NO RPM told hot and cold engine, and parked or driven, that is huge clue that
is the thermostat stuck open?> not a 180f to 200f coolant scanned.

voltage goes down? if battery voltage on 800rpm HOT running engine
falls below 13.3vdc the alternator is failing
13.3 to 14.7 is par, running, below never.
key off is 12.6v SOC 100% fully charged.


Limp on the engine, PCM , means gross engine control errors
of senors or actuators or even a bad engine.
and all set DTC errors you forgot to do that. scan it first.
Check engine lamp glows running is the 1st clue
A.K.a. CEL, SES OR MIL LAMP.

there are lots of symptoms not told and good and bad both matter !!
and no tests done at all. parts replaced sure.
tell more evidence. or do the tests. both.

You should NOT be driving this vehicle if it is in limp mode. You will need to pay a Good Auto-electrician to look at this problem.
All modern cars and trucks are fitted with electronic control units referred to as the PCM and the TCM. P1698 refers to these units not communicating properly with each other. So the vehicle goes into a safety set up until the problem it fixed, Limp Mode.

What year an model SAAB ? U - codes are communication network trouble codes . All the control modules , PCM/ECM - BCM , ABS , air bag etc... all share info on this serial data communication net work . When a module goes off line or wiring problems set these type codes . Your best bet , take it to a qualified repair shop.

Did you change any modules on the vehicle ?
B2900 VIN Mismatched ABS Module VERIFY that the module has the correct as-built data.
CHECK for correct powertrain control module (PCM) and ABS module configuration using the diagnostic tool. RECONFIGURE the component as necessary. FOLLOW the diagnostic tool directions for the ABS module configuration or REFER to Section 303-01A or Section 303-01B for the PCM. CLEAR the DTC. REPEAT the C1805 Mismatched PCM and/or ABS/TC Module ABS Module CHECK for correct PCM and ABS module configuration using the diagnostic tool. RECONFIGURE the component as necessary. FOLLOW the diagnostic tool directions for the ABS module configuration or REFER to Section 303-01A or Section 303-01B for the PCM. CLEAR the DTC. REPEAT the self-test. U1073 SCP (J1850) Invalid or Missing Data for Engine Coolant PCM REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual. U1262 SCP (J1850) Communication Bus Fault Network Fault REFER to Section 418-00 . Can a scan tool communicate with all the modules on the vehicle ?

• The anti-lock brake system (ABS) module or stability assist module (if equipped) does not respond to the diagnostic tool

• Circuit or connection in the standard corporate protocol (SCP) network.
• ABS module.

• Go To Pinpoint Test A .

U1123 Invalid or Missing Data For Odometer Instrument Cluster Go To Pinpoint Test G . U1059 SCP (J1850) Invalid or Missing Data for Transmission/Transaxle/PRNDL PCM REFER to Powertrain Control/Emissions Diagnosis (PC/ED) manual. U1041 SCP (J1850) Invalid Or Missing Data For Vehicle Speed Instrument Cluster REFER to Section 413-01 . U1041 SCP (J1850) Invalid Or Missing Data For Vehicle Speed Tire Pressure Monitoring System Module REFER to Section 204-04 . You need to take it to the dealer , not a transmission shop. Your vehicle could have a ground issue , could have power issue , could have a control module issue . It needs to be hooked up to the factory scan tool ! It is for sure it has a communication problem on the SCP data bus , do you know what serial data communication is ?
The vehicle has 3 module communication networks:

• the standard corporate protocol (SCP) communications network
• the international standards organization (ISO) 9141 communications network
• the universal asynchronous receiver-transmitter (UART) based protocol (UBP) communications network

The diagnostic tool connects to all 3 networks through the data link connector (DLC). This makes diagnosis and testing of these systems easier by allowing one diagnostic tester to be able to diagnose and control any module on the 3 networks from one connector. The DLC can be found under the instrument panel between the steering column and the radio.
The SCP communications network will remain operational even with the severing of one of the bus wires. Communications will also continue if one of the bus wires is shorted to ground or voltage, or if some but not all termination resistors are lost. The SCP communications network allows inter-module communication.
The ISO 9141 communications network does not permit intermodule communication. When the diagnostic tool communicates to modules on the ISO 9141 communication network, the diagnostic tool must request all information, or initiate module commands.
The ISO 9141 communications network will not function if the wire is shorted to ground or battery voltage. Also, if one of the modules on the ISO 9141 communications network loses power or shorts internally, communications to that module will fail.
The UBP communications network will not function if the wire is shorted to ground or voltage. The UBP is different from the ISO communication network in that it allows intermodule communication.

limp mode means something is broken, with
PCM or TCM. (bad sensors or actuators)
resetting PCM.
1: press reset on scan tool.
2: pull memory fuse to ECU.
3: pull battery neg lug and radio bricks and need to do relearn modes. on many things.

if the problem remains, resetting it does nothing, it come back fast.

I have a 2005 Pacifica that is in limp mode. We have changed the PCM and all the senser and siloniod checked every wire etc. What else could it be?

Hi, limp mode or (limp-in mode or limp-home mode)occurs when your computer in your car is not communicating with the sensors on your engine. On some cars(volkswagon Passat for example) If you disconnect the battery then the computer will lose all of the settings and will go into limp-in mode.
The car will have little power and a top speed of only about 30 miles per hour.
The function of limp-in mode is to get you to a place that can repair the car but the car is barely drivable.

LIMP MODE.THATS PCM FAULT.LIMP MODE IS THE PCM SYSTEM IN OVER RIDING MODE TO GET CAR SAFELY HOME OR GARAGE.

It sounds like your transmission is in limp mode. Your first gear will never make it to 1st gear, the gear ratio is to low and the engine would over rev causing it to shut down.
Before guessing at transmission problems, check the fluid level (car warmed up, engine running in Park on level ground) and have the PCM scanned for trouble codes FIRST. This guide is meant for problems that do not show up as PCM codes (like shift A&B solenoid failures, for example).
Many problems that show up as transmission issues are actually PCM or electrical, and may be external to the transmission. Try a different PCM, and check for chafing where the cables come out of the PCM.
What is "limp-home mode" ? This is a fault mode in which the transmission either loses electrical power or the PCM deactivates all of the electronics. The transmission will default to max line pressure. The driver will have Reverse and 3rd, with manual 2nd available by putting the gearshift in 2 or 1 (doesn't matter). 1st, 4th, and TCC lockup will not be available. It will not hurt the car to drive it like this for short periods, but use manual 2nd to get the car moving, and be aware that the trans will generate more heat than normal while operating in limp-home mode due to increased torque converter slippage during 2nd gear starts and no lockup in 3rd gear.
Start with the reputable transmission shop that can test your transmission and the reputable ones will do this free of charge and will take there time to explain to you your SRX transmission issues and what actions need to be take to resolve the problem.
Thank you for using fixya.

you have to change the solenoid control if your car is 3.5 engine the solenoid control located at inside the transmission..