# How to remove G251 longitudinal sensor



## John-H (Jul 13, 2005)

*How to remove G251 (Pitch - longitudinal) sensor*

This is one of the sensors for the ESP system which detects acceleration / braking or g-force in a longitudinal direction (pitch) as opposed to sideways g-force on cornering (roll) handled by the G200 sensor. Both are single axis acceleration sensors and both the same part (1J0 907 651 A) but just mounted differently - one 90° to the other. The lateral (roll - G200) sensor is mounted under the steering column and the longitudinal (pitch - G251) is mounted behind the glove compartment on RHD UK Mk1 TT vehicles.

See here for a guite on how to repair the sensors: Repair. Commonly it's just dry joints on the chip because off poor soldering.

See here for a guide by shaneg for removal of the G200 sensor: Lateral-G200-Removal.

The removal of the G251 sensor behind the glove box is similar and shown here:

*G251 Removal*

First, remove anything heavy from the glove compartment, then remove the side cover of the dashboard:










Remove all the Torx screws on the side - bar the one with the blob of paint:










Then take out the intermediary pannel:










Undo the Torx screws along the top of the glove compartment - but leave one in place for support:










Remove the bottom screws - careful as the glove compartment will swing loose:










At this point the glove compartment will be hanging by one screw at the top. Carefully undo the remaining screw whilst supporting the glove compartment and slowly lower, being careful to remove the connector for the light and airbag switch:


























Only one connector is on a short lead so it's possible to remove just this one and let the compartment rest on the floor:










The G251 sensor is high up top left. Gently push back the locking tab of the G251 sensor connector and remove it:


















The G251 sensor can be removed by prising down the lower (loose) part of the spring clip bracket and the sensor can then be pulled away:










Replacement is the reverse process. Do remember to reconnect all the connectors


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## alistairr24 (Apr 21, 2015)

Thank you for excellent instructions, removed mine gave it a good shake seams to have sorted the problem as ABS warning lamp is currently off all good for mot in a fews days fingers crossed.

Managed it without removing glovebox real bonus


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## John-H (Jul 13, 2005)

Well done. It may need repair in the long run as it could be a dry solder joint judging by the one I took apart and reports from others.


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## Polak1992 (May 4, 2015)

you know where i can buy this sensor? I cant find anywhere


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## John-H (Jul 13, 2005)

An Audi dealer or TPS. I've not enquired at GSF.


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## Polak1992 (May 4, 2015)

you know the price maybe? Propably over 100 pounds ;/


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## John-H (Jul 13, 2005)

Probably. Alternatively you could repair it: 
viewtopic.php?f=2&t=435953&p=3146097


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## Polak1992 (May 4, 2015)

Can i send it to repair somewhere?


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## lukeroberts18 (Apr 24, 2015)

Hello, so is the longitudinal sensor the exact same part as the lateral sensor? Also, once the part has been changed is that it or does it have to be programmed with vag-com? cheers
Luke


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## CollecTTor (Jan 17, 2014)

lukeroberts18 said:


> Hello, so is the longitudinal sensor the exact same part as the lateral sensor? Also, once the part has been changed is that it or does it have to be programmed with vag-com? cheers
> Luke


Yes, they need to be calibrated/zero'ed/centered so the car knows what the sensor is telling it. Can be done with VAG COM.

John, it's interesting that you call one a longitudinal sensor and the other a yaw sensor, after stating they are both single axis accelerometers. That would make the second sensor a lateral acceleration sensor, since yaw is rotation about the vertical or Z axis.  The ECU just uses both to determine yaw. I'm having an issue with my sensor, which randomly causes the ESP to freak out and apply one corner's brakes while travelling at highway speeds in a straight line.  Sounds like I may have the broken solder failure....


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## John-H (Jul 13, 2005)

CollecTTor said:


> lukeroberts18 said:
> 
> 
> > Hello, so is the longitudinal sensor the exact same part as the lateral sensor? Also, once the part has been changed is that it or does it have to be programmed with vag-com? cheers
> ...


Thanks for that you are right and I don't know how that slipped in - it should be roll (now corrected). There is a yaw sensor G202.


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