R50/53 The cursed TMAP sensor
#1
03-12-2019, 02:41 PM
The cursed TMAP sensor
My R53 JCW’s TMAP sensor was crumbling so I ordered a replacement from Out Motoring (who have been fantastic to deal with, btw). The first was DOA and never registered anything other than 0.0 on my ScanGauge. It was returned under warranty and I’ve replaced it with a second. It shows values
on the ScanGauge that are typical when I rev the engine. But when I put it in gear and try to move, the engine bucks, then dies, and throws the usual codes for TMAP. I can swap out the old one and everything’s great. Put in the new one, and the engine dies.
Some data points to add:
on the ScanGauge that are typical when I rev the engine. But when I put it in gear and try to move, the engine bucks, then dies, and throws the usual codes for TMAP. I can swap out the old one and everything’s great. Put in the new one, and the engine dies.
Some data points to add:
- I cleared the adaptations with ISTA. No change
- The one out motoring put in was OEM but not the same manufacturer as the one already in there, which I believe to be original. See pic for details. Out advises there doesn’t appear to be any spec change over the years.
- I acquire an NGK from Rock Auto and it exhibits the same behavior as the OEM from Out Motoring. Long story on why I had this one, but it’s listed on the Rock site as being for 2003 models and not 2006. Weird.
Am I going to have to build a test rig to check out the values being returned by these guys?
Old on the left, new on the right.
Last edited by mslatter; 03-13-2019 at 06:32 PM. Reason: Typos
#3
03-12-2019, 03:07 PM
#4
03-12-2019, 06:59 PM
I’ll certainly research, but check the number stamped on the upper right of the new sensor. It matches the part number, other than the 12 14 part, and I think the bag it came in was labeled with the 12 14 part. I do think this is the right part. Why it looks so different is a question for BMW, but I assume it’s just them changing suppliers over the years. But it shouldn’t behave differently, I’d think.
#6
03-12-2019, 07:49 PM
Just throwing it out there but there may be different part numbers for the pre and post facelift models. The picture of the part posted looks more like your OEM piece.
When my Jeep XJ needed a crank sensor, I bought 4 different sensors from various suppliers and none worked. Bought one from the dealer and she runs like a top. Sensors can be weird.
When my Jeep XJ needed a crank sensor, I bought 4 different sensors from various suppliers and none worked. Bought one from the dealer and she runs like a top. Sensors can be weird.
#7
03-13-2019, 07:25 AM
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#8
03-13-2019, 09:12 AM
I’ll certainly research, but check the number stamped on the upper right of the new sensor. It matches the part number, other than the 12 14 part, and I think the bag it came in was labeled with the 12 14 part. I do think this is the right part. Why it looks so different is a question for BMW, but I assume it’s just them changing suppliers over the years. But it shouldn’t behave differently, I’d think.
#9
03-21-2019, 07:32 AM
I ended up replacing it with an off-brand (the dealer’s price was really high) and it ran fine for a few hundred miles. Now, I’m getting P1238, which seems to be for the other MAP sensor. The car runs fine but the SES is lit. I’m going to go deeper on the diagnosis later today, but is the performance of sensor 2 somehow related to the performance of sensor 1?
#10
03-21-2019, 08:15 AM
I ended up replacing it with an off-brand (the dealer’s price was really high) and it ran fine for a few hundred miles. Now, I’m getting P1238, which seems to be for the other MAP sensor. The car runs fine but the SES is lit. I’m going to go deeper on the diagnosis later today, but is the performance of sensor 2 somehow related to the performance of sensor 1?
#2 - the MAP sensor - will give you a 1237 and read low manifold pressure.
#1 - the T-MAP sensor - will give you the 1238 and read high manifold pressure.
Did you keep your old T-MAP,? If so, try swapping it back in, if nothing changes, there's a good chance the new sensor is bad already.
Also, try cleaning the probe bubble, quite often the sensors go bad from fouling do to burnt on oil residue from the intake tract, it may not be completely toast yet.
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Onizukachan (08-20-2022)
#11
03-21-2019, 05:43 PM
I don't know if this is the rule, but it's how mine work...
#2 - the MAP sensor - will give you a 1237 and read low manifold pressure.
#1 - the T-MAP sensor - will give you the 1238 and read high manifold pressure.
Did you keep your old T-MAP,? If so, try swapping it back in, if nothing changes, there's a good chance the new sensor is bad already.
#2 - the MAP sensor - will give you a 1237 and read low manifold pressure.
#1 - the T-MAP sensor - will give you the 1238 and read high manifold pressure.
Did you keep your old T-MAP,? If so, try swapping it back in, if nothing changes, there's a good chance the new sensor is bad already.
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Here2Go (12-25-2021)
#12
03-21-2019, 09:15 PM
We ONLY use and recommend the original MINI Map sensors and never have issues like this with them. So my suggestion would be to get factory sensors and be done.
https://www.waymotorworks.com/map-se...-cooper-s.html
https://www.waymotorworks.com/map-se...-cooper-s.html
#13
05-09-2019, 07:00 PM
Just to wrap this oldish thread up, the P1698 was fixed by replacing the TMAP sensor, which was crumbling and fell of its connectors. The P1242 was fixed by correcting vacuum leaks. My particular one was at the Bypass valve where the JCW has a T-connector to supply vacuum to the air box. And, finally, I cleared P1238 by replacing the MAP sensor. It’s possible in all my fiddling with the TMAP, that I pulled on wires enough to break something in the MAP, or it was just a timing coincidence, or some other reason that working on that TMAP also required me to replace the MAP. But it seems so far to be the lasting fix, and I’m posting it so future searchers or said codes can find some help.
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