Subaru Impreza 2004 Service Manual page 15

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
Step
2 CHECK CURRENT DATA.
1)Repair the battery short circuit in harness
between ECM and rear oxygen sensor connec-
tor.
2)Turn the ignition switch to ON.
3)Read the data of rear oxygen sensor heater
current using Subaru Select Monitor or the
OBD-II general scan tool.
NOTE:
•Subaru Select Monitor
For detailed operation procedure, refer to the
"READ CURRENT DATA FOR ENGINE".
<Ref. to EN(H4DOTC)(diag)-32, Subaru
Select Monitor.>
•OBD-II general scan tool
For detailed operation procedure, refer to the
OBD-II General Scan Tool Instruction Manual.
3 CHECK POOR CONTACT.
Check poor contact in ECM connector.
Check
Is the current more than 7 A?
Is there poor contact in ECM
connector?
EN(H4DOTC)(diag)-94
Yes
Replace the ECM. END
<Ref. to
FU(H4DOTC)-49,
Engine Control
Module (ECM).>
Repair the poor END
contact in ECM
connector.
No