Subaru IMPREZA 2004 Service Manual page 539

Diagnostic Procedure with Diagnostic Trouble Code (DTC)
ENGINE (DIAGNOSTICS)
BT:DTC P0866 TCM COMMUNICATION CIRCUIT HIGH
• DTC DETECTING CONDITION:
• Two consecutive driving cycles with fault
CAUTION:
After repair or replacement of faulty parts, conduct Clear Memory Mode <Ref. to EN(H4SO)(diag)-47,
OPERATION, Clear Memory Mode.> and Inspection Mode <Ref. to EN(H4SO)(diag)-40, OPERATION,
Inspection Mode.>.
• WIRING DIAGRAM:
B56
B137 ECM
Step
1 CHECK HARNESS BETWEEN ECM AND
TCM CONNECTOR.
1)Turn the ignition switch to ON.
2)Measure the voltage between ECM and
chassis ground.
Connector & terminal
(B137) No. 19 (+) — Chassis ground ( − − − − ):
TCM
EN(H4SO)(diag)-230
1 2 3 4
10 11 12
19 20 21
Check
Is the voltage more than 10 V? Repair battery
B56
5 6 7 8 9
13 14 15 16 17 18
22 23 24
B137
3 4
1 2
5 6 7 8 9 10 11 12 13
14 15 16 17 18 19 20
Yes
Go to step 2.
short circuit in har-
ness between
ECM and TCM
connector.
EN-01600
No