Brake Pressure Sensor (DSC/ABS/BRAKE Trifecta)

Originally Posted by Microflight

how does the code P0500 translate to English.

It's in the picture below from my bogus smog failure from the referenced thread.
- P0500 Vehicle Speed Sensor Malfunction

2003 E 39 After a previous post I made starting with an 81 error code which would have been the brake pressure sensor, I back probed the sensor and saw that it was giving credible values. I then concluded ( guessed) that it was the module.

A BMW tech friend identified a rebuilder that he used and liked - Module Master in of all places Moscow Idaho (actually near Spokane Washington) phone 888-892-0764 and on the web.

They quoted 300 for the Bosch 5.7 module. Their terms are 5 day turn. If the Module has no error on the inbound check, there is only the shipping charge. If the module is unrepairable, for $75 additional they will send you a good unit - remembering that you will have to reprogram the VIN into it so there would be that additional charge when you got it back. Module Master provides a 5 year warranty.

I sent the module, they repaired and returned it to me. I installed it and the ABS, DSC and Brake warning lights went out on start - normal. One day later aver a number of short trips the service engine soon light also went out. NERVANA

The report from Module Master is as follows: "Repaired damage to power return circuit and 8 line sensor driver section to restore proper module operation. Installed high current shunt to protect power return circuit from future failure. Unit now powers up and executes self test and functions perfectly on test fixture without any error codes."

I conclude that this module was unerdesigned and while surviving for a number of years was bound to fail. Given the number of failures and the common knowledge among the Indy's I know that they immediately are aware and have experienced the problem with the module

As for error codes, one has to be careful in assessing a fault code that is based upon a network communication like the ABS module. I am certain from the DME and ABS module prospective, the error is that it is not receiving the communication from the Brake Pressur Sensor, but once you verify the brake pressure sensor is sending signal, the culprit are the wires or the module as was the case here in the module.

While I could have opened the module and attempted the repair, I sense that it would be sublect to failure again without the shunt. $300 is a lot - peace of mind is priceless

Originally Posted by Microflight

81 error code ... I back probed the sensor and saw that it was giving credible values

The anecdotal evidence is overwhelming that the 81 code is bogus (most of the time). In fact, I can't remember a single incidence of the 81 being real (but I am no expert and not everyone is on the forums). Point is that the 81 error code 'should' be further tested before believing it.

Originally Posted by Microflight

A BMW tech friend identified a rebuilder that he used and liked

See also:
- What are all known options when your ABS control module is bad (1)

Originally Posted by Microflight

As for error codes, one has to be careful in assessing a fault code that is based upon a network communication like the ABS module.

Bill (540iman) would be proud of you! You're one of the few who realize the inability to get isolation readings without actually isolating the components under test.
- Explanations by 540iman as to why the fancy diagnostic tools very often (extremely often, like almost all the time) fail to properly diagnose the trifecta or bifecta (1) (2) (3) (4) (5) (6)

Originally Posted by Microflight

I sent the module, they repaired and returned it to me.

Thanks for the update. I will append it to the canonical ABS trifecta thread:
- How to diagnose the BMW amber ABS BRAKE DSC/ASC trifecta or bifecta (1)

See also this thread today, by Poolman, which discusses how to properly REMOVE the brake pressure sensor:
- Brake pressure sensor