Subaru Impreza 2003 Service Manual page 3301

DIAGNOSTICS CHART WITH DIAGNOSTIC TROUBLE CODE (DTC)
E: DTC P1574 KEY COMMUNICATION FAILURE
DIAGNOSIS:
• Failure of IMM ECM to verify key (transponder) ID code
Step
1 CHECK IMM ECM FUNCTION.
Insert the key to ignition switch (LOCK posi-
tion), measure changes in voltage between
Antenna connector.
Connector & terminal
(B142) No. 1 — No. 2:
2 CHECK IGNITION KEY (TRANSPONDER).
1)Remove the key from ignition switch.
2)Start the engine using other keys that have
undergone the teaching operation, furnished
with vehicle.
F: DTC P1576 EGI CONTROL MODULE EEPROM
DIAGNOSIS:
• ECM malfunctioning
1. REPLACE ECM.
Replace the ECM.
<Ref. to FU(H4SO)-48, Engine Control Module (ECM).>, <Ref. to FU(H4SOw/oOBD)-43, Engine Control
Module (ECM).> or <Ref. to FU(H4DOTC)-49, Engine Control Module (ECM).>
Then perform teaching operation. Refer to the teaching operation manual (Pub. No. S0820GZ).
G: DTC P1577 IMM CONTROL MODULE EEPROM
DIAGNOSIS:
• IMM ECM malfunctioning
1. REPLACE IMM ECM.
Replace the IMM ECM <Ref. to SL-39, Immobilizer Control Module.>, and then replace all ignition keys (in-
cluding the transponder). Then perform teaching operation. Refer to the teaching operation manual (Pub.
No. S0820GZ).
Check
Is the voltage −30 to 30 V?
(Approx. 0.1 second after
inserting the key) Is the voltage
0 V? (Approx. 1 second after
inserting the key)
Does the engine start?
IM-23
IMMOBILIZER (DIAGNOSTICS)
Yes
Go to step 2. Replace the IMM
ECM <Ref. to SL-
39, Immobilizer
Control Module.>
and then replace
all ignition keys
(including the tran-
sponder). Then
perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
Replace the igni- Replace the IMM
tion key (including ECM <<Ref. to SL-
the transponder). 39, Immobilizer
Then perform Control Module.>
teaching opera-
and then replace
tion. Refer to the all ignition keys
teaching opera- (including the tran-
tion manual (Pub. sponder). Then
No. S0820GZ). perform teaching
operation. Refer to
the teaching oper-
ation manual (Pub.
No. S0820GZ).
No