EVO Steering - Fault Code 50 Cannot Set
90cadillac13Bulletin No. T-91-16
File in Group 8
Number 125
Corp.Ref.No. 018118
Date Oct. 1990
SUBJECT: ELECTRONIC VARIABLE ORIFICE (EVO) STEERING FAULT CODE
MODELS AFFECTED: 1991 BROUGHAMS
1991 Broughams built before VIN breakpoint 701000 cannot set code 50 (loss of EVO steering) in diagnostics due to a problem in the ECC head. 1991 Broughams built after VIN breakpoint 701000 are unaffected and will set code 50 if an EVO steering fault is present.
To repair a 1991 Brougham built before VIN breakpoint 701000 with an EVO steering concern, perform the EVO system check as indicated on page 3B7-9 of the Service Information Manual. If the EVO system check diagnosis chart leads to "no problem found", follow diagnostic chart B, ECC code 50, found on page 3B7-11 as if code 50 were present. Do not replace the ECC head in vehicles before VIN breakpoint 701000 to repair this condition.