Check Engine Light- 4C52, 474D Codes- Resolution

[ard]

I thought I’d post a new thread on this issue- this issue has been reported elsewhere on the diesels, but not coherently.

Key Words:

Check Engine Light
4C52 CHARGE AIR TEMP. PLAUSIBILITY
474D INTERCOOLER TEMP. PLAUSIBILITY
2010 X5 35D diesel


The story:

My check engine light came on a few weeks ago. I pulled the code and found it to be an intake air fuel issue (generic code reader, my BMW reader will not work on the diesel).



I needed to have the first oil and DEF service done, so I took it to the dealership. 9600 Miles, Oilservice warning just started.

Tech reported an intercooler temp error. 474D. They just reset it, since there was no ‘active code’ (ie it wasn’t throwing it repeatedly) and BMW has no published service advisory for the 474D code.

I wasn't thrilled, but the tech had rarely dealt with diesels. We discussed it for a bit, and I pointed him to Xoutpost and BF for more details of this issue, including what solutions are being reported. He agreed to look into the issue. He was thankful for the heads up as BMW really does not provide dealers/techs with 'raw data'- they only get info when BMW has resolved an issue and has a solution.

Anyway the CEL came back on 4 days later on a Monday. Same generic code. I had actually pre-scheduled a visit this Thursday with a loaner …(knowing that the CEL might be a recurring theme, I had scheduled two visits on consecutive weeks just in case ). I do not like to be a victim, by booking I was protecting myself from the 'sorry we don’t have a loaner' dance. I live 45 miles away.

They had to keep the car for a while- they could not duplicate the failure, and went on to open a PUMA. They suspected a potentially ‘blocked’ intercooler. They removed and inspected the IC: fine. (Not an unreasonable query- If you have a blockage through the intercooler, the altered airflow can cause “implausible” temperature measurements.)

In the end, he replaced the intake temperature sensor and reprogrammed the DDE. Effectively following other reports of fixes for the ‘4C52 error’ that have been reported. Although mine was not the same error, it seemed to be a reasonable culprit… I promised to report the success of this fix.

Happy to report that so far it has been 12 days and no more codes.

I suspect a bad ‘batch’ of sensors. It is pretty easy to get a temperature offset in a sensor- a few degrees with the wrong solder or wire, or just improperly calibrated during sensor manufacture, such that the DDE is getting a value that is outside the operating envelope. It would be ‘silent’ too- the sensor is properly streaming data, there is no ‘open’ or short- just inaccurate. It will only show up indirectly when you need to ‘do’ something with the reading- in this case measuring the relative temperatures between (possibly) ambient or intake air and compressed, post turbocharger air.


A


PS Oil service done with no issues- SLX oil used, ~2.5 "units" of DEF (each unit is 2.5gallons) so a total of 6.5 Gallons of DEF used. No idea how much remained when they began the service.

[FunfDreisig]

Originally Posted by ard

....My check engine light came on a few weeks ago. I pulled the code and found it to be an intake air fuel issue (generic code reader, my BMW reader will not work on the diesel).......

Thanks for the followup report.

FWIW when the Air Temp Sensor was replaced on our 2009 35d my generic OBD II code reader reported code P007B. The dealer's paper work listed "4C52 CHARGE AIR TEMP SENSOR PLAUSIBILITY". And the actual part they replaced was "13-62-7-812-741 TEMPERATURE SENSOR"

Funf Dreisig

[ard]

Posted in another thread:

Originally Posted by TitanM5

Wife's 35d just came back from an overnite at the dealer for a parking brake failure message.. Anyone had that one yet? Repair order says: Perform ISID test, found fault 6011 emf control unit internal fault, not present, chk wiring @emf connector & harness for chafing. OK. clear faults, cust to monitor" Looks like they didnt find anything and just reset the display.

While in there, they said they were performing 2 "campaigns". Here's what the RO says they did:

Job #2- Perform recall 13-03-10. Program & encode w/CAS

Job #3- Perform recall 13-04-10. Replace charge air temp sensor. Parts: 1- P/N: 13-62-7-812-741 Temp sensor.

This must be the 2 'recalls' people are talking about. Anyone know what the jargon above refers to?

Seems BMW figured out this was a systemic failure- not a safety recall- and is performing a campaign as cars come into the dealership for other service.


A

[killcrap]

Originally Posted by ard

Posted in another thread:


Seems BMW figured out this was a systemic failure- not a safety recall- and is performing a campaign as cars come into the dealership for other service.


A

there is a campaign to replace the sensor and update the DDE software.

[Taj Khan]

HI,
you stated the in 3.0 engine the wiring harness as faulty. has this ever happened and where abouts is the harness and how to change it.

Thanks

[Speciald14]

Originally Posted by killcrap

there is a campaign to replace the sensor and update the DDE software.

had these done when took 35d in for a front passenger side oil leak they replaced seal on charge air pipe to turbo charger....

now 35d is back in with the CEL light on...SA said it has to do with the exhaust so could be the exhaust sensor????

i will report back when i hear back....

[ard]

Originally Posted by Speciald14

i will report back when i hear back....

Don't. At least not here. Unless it is confirmed to be a 4c52 or 474d code....

Otherwise this just turns into one big "hey my CEL came on" thread.


Curmudgeonly yours,

A

[petert]

Had exactly this recently on my 2010 35d. Dealer replaced charge air temperature sensor and reprogrammed DDE. Only other change I have noticed is that cruise control speedo indicator works differently. Small indicator stays in position when cruise is disengaged using brake pedal or stalk. Indicator then drops to zero/invisible when stalk used to disengage again.

Peter T

[ard]

Originally Posted by petert

Had exactly this recently on my 2010 35d. Dealer replaced charge air temperature sensor and reprogrammed DDE. Only other change I have noticed is that cruise control speedo indicator works differently. Small indicator stays in position when cruise is disengaged using brake pedal or stalk. Indicator then drops to zero/invisible when stalk used to disengage again.

Peter T

So here in the US there was a recall/corrective action to do exactly what they did to fix this for you.... did they not have this corrective action where you are?

[petert]

The service advisor mentioned the recall and of course I asked 'so how come I've not been contacted about it and only know when I bring it in to have the problem fixed?'. His reply was that in Canada the privacy laws mean that BMW have to ask the government for drivers addresses and that takes a long time (rather than using their own records?...) and it often happens that people bring their cars in before BMW have had a chance to contact them.
I don't know if this is true or not (I'm not Canadian and have only been here a year) but it sounds silly to not do a recall for those reasons: what if the issue was safety related?
Anyway, that's the answer to the question, unsatidsfactory though it sounds.
Peter T