Subaru Legacy 2004 Service Manual page 4069

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
C: DTC P1571 REFERENCE CODE INCOMPATIBILITY
DTC DETECTING CONDITION:
Reference code incompatibility between body integrated unit and ECM
Step
1 PERFORM TEACHING OPERATION ON IG-
NITION KEY.
Perform teaching operation on all keys of the
vehicle. Refer to "REGISTRATION MANUAL
FOR IMMOBILIZER".
Check
Is the teaching operation for all
keys completed?
IM(diag)-21
IMMOBILIZER (DIAGNOSTICS)
Yes
END. Replace the ECM.
<Ref. to FU(H4SO
2.0)-34, Engine
Control Module
(ECM).> <Ref. to
FU(H4SO 2.5)-36,
Engine Control
Module (ECM).>
<Ref. to
FU(H4DOTC)-35,
Engine Control
Module (ECM).>
<Ref. to
FU(H6DO)-34,
Engine Control
Module (ECM).>
Replace the body
integrated unit
<Ref. to SL-46,
Body Integrated
Unit.> and replace
all the ignition keys
(including tran-
sponder). Execute
the registration
procedure next.
Refer to "REGIS-
TRATION MAN-
UAL FOR
IMMOBILIZER".
No