Five most com­mon EPS fail­ures

Car Mechanics (UK) - - Steering Guide -

1. Ford Fo­cus MKIII, C-MAX MKII, Kuga MKI, Tran­sit Con­nect (2011-2017)

The ba­sic hard­ware used is the same through­out the Ford fam­ily of elec­tric steer­ing racks, with dif­fer­ent soft­ware pro­vid­ing each ve­hi­cle’s char­ac­ter­is­tics. In this de­sign, a mo­tor is at­tached di­rectly to the rack that drives a lin­ear re­cir­cu­lat­ing ball wor­m­drive via an in­ter­nal belt. Un­for­tu­nately, the con­trol unit that is built into the mo­tor assem­bly on the near­side of the steer­ing rack suf­fers from both hard­ware and soft­ware fail­ures. The con­trol unit stops com­mu­ni­cat­ing with the car’s body con­trol mod­ule – look for the com­mon fault code of ‘U3000 -49/53’. It is thought that soft­ware up­dates alone give only a short-term fix.

2. Vaux­hall Meriva Mk1

Bizarrely, the orig­i­nal Meriva used a col­umn-mounted EPS that was not shared with other Vaux­hall mod­els. Should the PAS fail com­pletely (and/or the EPS warn­ing lamp il­lu­mi­nates), the as­sis­tance level will vary, de­pend­ing on di­rec­tion, or if the steer­ing groans/vi­brates. The steer­ing torque sen­sor is the most com­mon cause. Look for code ‘C1500’. While the sen­sor can be re­newed sep­a­rately, the con­trol unit will re­quire cal­i­brat­ing. Al­ter­na­tively, in­ter­mit­tent fail­ure that is ac­com­pa­nied by code ‘C1002’ in­di­cates com­plete mo­tor con­trol unit fail­ure, re­quir­ing a re­place­ment col­umn.

3. Fiat Panda (2004-2014), 500 and Grande Punto (to 2014)

EPS is­sues con­tin­ued with Fiat cars long af­ter the Punto ended pro­duc­tion. The Panda and 500 mod­els suf­fer also from high fail­ure rates of their columns, al­though the Panda col­umn is unique. Like the Vaux­hall Meriva, the steer­ing torque sen­sor is the main cause of fail­ure (gen­er­at­ing code ‘C1002’) and the symp­toms are the same as those de­scribed ear­lier. You can re­place the Panda’s sen­sor sep­a­rately. How­ever, the code ‘C1001’ in­di­cates mo­tor con­trol unit fail­ure and re­plac­ing the col­umn will be re­quired. Like that of our Punto demon­stra­tion, a cor­rect­lyre­man­u­fac­tured col­umn should not re­quire any fur­ther pro­gram­ming. Un­like those of the Panda and Punto, the Grande Punto’s Del­phi EPS col­umn is of a dif­fer­ent de­sign, where the col­umn, mo­tor and ECU are in­te­gral. Should there be any is­sues, the en­tire col­umn will have to be re­placed. While not in­ter­change­able, the same prob­lem strikes the columns fit­ted to the ba­sic 500 model.

4. Volk­swa­gen Golf MKV and MKVI, Audi A3 (to 2013)

Three dif­fer­ent types of EPS racks were fit­ted to these ve­hi­c­less. The first types lasted un­til 2005, Zf-man­u­fac­tured racks were fit­ted from 2005-2009 and the last gen­er­a­tion ran from 2009-2013. In gen­eral, the newer ones are the most re­li­able. Fail­ures arise due to wa­ter ingress into the rack from poorly-fit­ted, or split gaiters. Fail­ure of the top pin­ion seal can al­low wa­ter and dirt to seep into the rack’s mech­a­nism. Torque sen­sor fail­ure within the rack is a known is­sue, as are mal­func­tions of the mo­tor/con­trol unit.

5. Vaux­hall Corsa D

Look for in­ter­mit­tent faults and not just to­tal fail­ure. Codes ‘C0460 (steer­ing an­gle sen­sor)’ or ‘C0545 (steer­ing torque sen­sor)’ mean that the col­umn will need re­plac­ing. Mo­tor prob­lems start in­ter­mit­tently, but end up be­ing per­ma­nent. The in­te­gral con­trol cir­cuit board in­side the mo­tor is known to burn out. Fail­ure of the chips within the EPS ECU can leave false di­ag­nos­tic codes, lead­ing you to sus­pect the mo­tor when the ECU is to blame. A new, or re­man­u­fac­tured, ECU must be matched and cal­i­brated di­ag­nos­ti­cally with the torque sen­sor. The steer­ing an­gle sen­sor is also a known weak­ness, re­sult­ing in the steer­ing be­com­ing lighter in one di­rec­tion than the other. It can also cause the ECU to shut down. As these columns seem to be in­trin­si­cally frag­ile and dif­fi­cult to cal­i­brate, it is rec­om­mended that the com­plete col­umn is changed, even though cer­tain in­di­vid­ual com­po­nents can be re­placed.

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