Honda Civic Service Manual page 459

[F16551l Th" ""un toot indicates Diagnostic Trouble
Code (DTC) P1681: TIVA,/TMB signal line failure
Problem verification:
1. Do the ECM Reset Procedure.
2. Drive the vehicle Ior several
miles at varying speeds
lnt.rmittent failure, system is OK
at ihis time. Check tor Poor con-
nections or loos€ wires at C131
llocated under right side of dash),
C438 ITCM) and ECM.
ls DTC P1655 indicated?
Check lor an oPen in the wire
(TMA line):
1. Turn the ignition switch OFF
2. Disconnect ECM connector C
( 3 1 P ) f r o m t h e E C M
3. Turn the ignition switch ON (ll).
4 - M e a s u r e v o l t a g e b e t w e e n
E C M c o n n e c t o r t e r m i n a l C g
and body ground.
C h e c k f o r a s h o r t i n t h e w i r e
ITMA line,:
Measure voltage between TCM
22P connector terminal No 7 and
body ground.
ls there battery vohage?
Ropair shod in the wire bstwe€n
the EcM (C!l) and the TcM.
ls there battery voltage?
Check for an open in the wire
{TMB line}:
1. Turn the ignition switch OFF
2. Reconnect ECM connector c
( 3 1 P ) .
3. Disconnect the 22P connector
from TCM.
4. Turn the ignition switch ON (ll).
5 . M e a s u r e v o l t a g e b e t w e e n
TCM 22P connector termlnal
No. 6 and body ground.
Repair open in the wire between
th€ EcM {Ca) and the TcM.
Check for a 3ho.t in the wire
{TMB lin6,:
Measure voltage between ECM
connector terminal C30 and body
ground,
ls there battery voltage?
S u b s t i t u t e a k n o w n ' g o o d E C M
and recheck. It symPtom/indica'
tion goes away, teplace the origi-
nal ECM.
Reoair short in the wile b6tween
the ECM {C30} and the TCM.
ls there baftery voltage?
f,epair open in the wire between
the EcM (C30) and the TcM.
I
J
A/T Signal (TMA/TMBI ('96 - 98 Dl6Y5 engine with GW)
ECM CONNECTOR C 131P}
TMA IGRYI
fcu22P
CONNECTOR
l l
TMB*
{PNK}
2 3 1
6 7 8 9 1 0
1 t '12
13 1 4 1 5 1 6 1 7 1 8
23 2a 25
29 30
Wire side oI temale
terminals
t l ,
1 1 - 1 8 9