[Stoo1701]

Hi gang,
Been getting intermittent messages "abs error, drive moderately", "brake & control failure, dive moderately" and "abs failure, drive moderately". Just had codes read, and got following:
Engine:
4a1f - Glow control unit (have a few glow related codes, lumpy start when cold, nothing new there)
40e9 - EGR controller position system
49a5 - LIN bus Communication
4e0f - swirl valve plausibility
4c9e & 9f - EGR valve plausibility
49f2 - Diesel electronics: message (speed, 0xCE)
Central info display:
9c53 - external open circuit (LVDS data line)
A46d - Central information display malfunction due to periphery

After clearing codes, only one left, the swirl flap possibility.

Which could be causing the messages, and how serious is this!?

Any pointers would be appreciated

 

[gbalthrop]

...Been getting intermittent messages "abs error, drive moderately", "brake & control failure, dive moderately" and "abs failure, drive moderately". Just had codes read, and got following:
Engine: ...

ONLY Diesel I have worked on was a Kubota. :rofl:

However, it appears that the codes you list are ALL related to the engine & Diesel Electronics. Yet the warning icons/messages you are concerned about ALL relate to the DSC (Dynamic Stability Control & ABS) module.

Who read those codes, with what software, and connecting to WHAT MODULE(S)?

If there is ANY doubt about what software/procedure was used in reading those codes, get someone who has INPA to connect to the DSC module and read codes and Freeze Frame Data saved in that module. Even IF you have an intermittent fault which is NOT currently present, the prior occurrences of faults (unless CLEARED) are still saved in DSC Module memory, along with any applicable Freeze Frame Data (Infospeicher).

There are MANY things that can cause those warning icons to light, or messages on the CID, but perhaps the most frequent cause, and relatively cheap/easy to fix is a problem with one of the four wheel speed sensors, its wiring, or connector.

INPA can give you real-time readout of signal from each wheel speed sensor to indicate the likelihood of a fault there, and which wheel is involved. It can also provide info/Data on other DSC functions.

Please let us know what you find,
George

 

[Stoo1701]

Ok, so codes now been read by a 'proper' reader, much more info.. but mostly the same codes,, glows, swirl flaps etc.. it's fair to say I need to get a intake mani off and clean it all out, change glow plugs & unit and blank/delete swirl flaps...

But also shows rotation errors on two wheel sensors, and three wheel speed sensor plausibility issues.. seems unusual that 3 wheels could simultaneously have errors with sensors.. logic would say the what they are connected to is having an error wouldn't it ? Is it the DSC? This seems the likely culprit of the messages on the screen...


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[Stoo1701]

I have seen very similar issues coming up from a bad battery terminal connection (something that is under recall, we are awaiting our turn for the repairs), or a bad voltage reg on the alternator.? How would I check the voltage ref on the alternator to see if it's functioning properly?


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[gbalthrop]

...But also shows rotation errors on two wheel sensors, and three wheel speed sensor plausibility issues.. seems unusual that 3 wheels could simultaneously have errors with sensors.. logic would say the what they are connected to is having an error wouldn't it ? Is it the DSC? This seems the likely culprit of the messages on the screen.

I have seen very similar issues coming up from a bad battery terminal connection (something that is under recall, we are awaiting our turn for the repairs), or a bad voltage reg on the alternator.? How would I check the voltage ref on the alternator to see if it's functioning properly?

Freeze Frame Data, particularly MILEAGE when a code is set, can be helpful to determine if more than one code was recorded in memory at the same time, in which case simultaneous individual component, wiring or connector issues are unlikely, and one should examine the circuit diagram and try to identify a "single cause" of "multiple concurrent faults." If no separate code for each wheel, and the "issues" are simply indicated by real-time sensor monitoring, then there is no help from freeze frame, so start with monitoring the 4 wheel sensors in INPA or otherwise, with the vehicle AT REST. If no reported anomaly, try reversing for a short distance.

If no reported anomaly still, try moving forward in a straight line, without turning steering wheel, and finally "slalom" turning wheel right to left. If there is any individual sensor issue, it should be apparent with that test.

We may be talking about different software/diagnostic programs. INPA shows wheel speed and direction of rotation (still, fwd, rev) for each separate wheel in real time, to allow you to determine if the reported data is consistent with vehicle movement, and if it is, then if there is ANY fault in the wheel speed sensors, it is only intermittent. I have NOT had any experience with fault codes in the DSC module, so can't say anything about Codes in Error Memory, or Freeze Frame Data related to those codes.

Here is the TIS Circuit Diagram for the 2008 330D E90 Sedan; if that is NOT your model (you gave no description) then drill down and insert VIN or correct model info to get correct diagram for your specific model:
https://www.newtis.info/tisv2/a/en/...es/a65a-dynamic-stability-control-dsc/iB2MO5O

As far as the alternator, I'm not sure what you mean by "voltage reference" but the alternator output voltage can be measured the same way you measure battery voltage, at the Jumpstart Terminal under the hood. To measure alternator output voltage, simply measure the voltage at the Jumpstart Terminal with the MOTOR RUNNING. Too little voltage normally would NOT cause DSC or ABS warnings on the dash, but there have been frequent reports of "over-voltage" causing those lights when alternator output exceeds 15V. Bentley quotes the range of 13.5 - 14.5V as normal.

George