{"product_id":"allison-nsbu-switch-2001-2004","title":"ACDelco 19540535 OE Allison 1000 5 Speed NSBU Switch, 2001-2004 GM 6.6L Duramax LB7","description":"\u003cp\u003e19540535 OE Allison 1000 5 Speed NSBU Switch\u003cbr\u003e\u003cbr\u003eFor 2001, 2002, 2003, 2004 6.6L GM Duramax LB7\u003cbr\u003e\u003cbr\u003eUpdated NSBU switch. One of the most common problems with the Allison transmission is failure of the Neutral Safety Back Up switch.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eSome of the symptoms of failure include but are not limited to:\u003c\/li\u003e\n\u003cli\u003eNo start condition\u003c\/li\u003e\n\u003cli\u003eGear shift indicator on dash not following properly\u003c\/li\u003e\n\u003cli\u003eTrans stuck in limp mode or fail safe\u003c\/li\u003e\n\u003cli\u003eDTC's set indicating pressure switch codes\u003c\/li\u003e\n\u003cli\u003eThis switch easily installs with just common hand tools.How does it work and why does it cause my transmission not to shift?The vehicle is equipped with a column type shift selector. In addition to the column shifter, another component associated with the shift selector is the Neutral Safety Back Up (NSBU) switch mounted on the selector shaft of the transmission. The NSBU switch transmits selector position information to the TCM. The NSBU switch mounts directly onto the transmission housing, from the outside, and detects the angular position of the shift selector shaft. This position is communicated to the TCM so that certain vehicle control functions can be coordinated with the position of the shift controls. The neutral signal output of the NSBU switch is typically used as confirmation that the transmission is in NEUTRAL or PARK before the engine starter is engaged.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eCommon trouble codes associated with NSBU failure include :\u003c\/li\u003e\n\u003cli\u003eDTC P0708, Neutral start\/backup (PNP or NSBU) switch\u003c\/li\u003e\n\u003cli\u003eDTC P0847, Pressure Switch Manifold (PSM)\u003c\/li\u003e\n\u003cli\u003eDTC P0872, Pressure Switch Manifold (PSM)\u003c\/li\u003e\n\u003cli\u003eDTC P0875, Pressure Switch Manifold (PSM)\u003c\/li\u003e\n\u003cli\u003eDTC P1711, Pressure Switch Manifold (PSM)\u003c\/li\u003e\n\u003cli\u003eDTC P1713, Pressure Switch Manifold (PSM)\u003c\/li\u003e\n\u003cli\u003eDTC U1000, Serial Data Communications\u003c\/li\u003e\n\u003cli\u003eBlank PRNDL Display\u003c\/li\u003e\n\u003cli\u003eFlashing PRNDL Display\u003c\/li\u003e\n\u003cli\u003eSlow or No Engagement of Automatic Transmission\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eThe reason that PSM codes may set is that the NSBU switch and the internal PSM switch \"look at each other\" and \"compare readings\" Basically, the NSBU switch lets the TCM know what gear position that you, the driver, have selected. The PSM has the job of telling the TCM what gear the transmission is in based on hydraulic inputs. If the data received from the PSM and the NSBU do not agree, the above mentioned trouble codes may set. The NSBU is subject to water contamination and will allow the switch to give faulty readings.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eReplaces# 29540479\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e","brand":"GM","offers":[{"title":"Default Title","offer_id":59803345617182,"sku":"19540535","price":245.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0679\/7171\/1262\/files\/29540479_f7797cc8-fd92-4c88-b182-81863348f184.jpg?v=1787077165","url":"https:\/\/platinumhpsolutions.com\/products\/allison-nsbu-switch-2001-2004","provider":"Platinum High Performance Solutions, LLC.","version":"1.0","type":"link"}