Honda Civic Service Manual page 407

I
Throttle Position (TP) Sensor ('99 - 00 Models except D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code {DTC) P0123: A high voltage problem in the Throftle Position
{TP) sensor circuit.
TP SENSOR 3P CONNECTOR {C11OI
sG2
{GRN/BLKI
voc2
{YEUBLU}
'l'
Wire side of female term;nals
ECM/PCM CONNECTOR C (31PI
Wire side of femal€ terminals
(cont'd)
1 1- 13 7
The MIL has been reported on
DTC P0123 is slored.
Problem verification:
1 . S t a r t t h e e n g i n e . H o l d t h e
engine at 3,000 rpm with no
load (in Park or neutral) until
t h e r a d i a t o r f a n c o m e s o n
then turn the ignition swatch
OFF,
2. Turn the;gnition switch ON (ll).
3 . C h e c k t h e t h r o t t l e P o s i t i o n
with the scan tool.
lntormittenl tailure, 3ystom is OK
at this time. Check tor Poor con'
neqtions or loo3€ wires at C'110
(TP sensorl tnd ECM/PCM.
ls there approx. 10% when the
throttle is fully closed and
approx. 90% when the throttle
is fully opened?
Ch€ck for an open in the TP s6n-
soJ:
1. Turn the ignition switch OFF.
2. Disconnect the TP sensor 3P
3. Turn the ignition switch ON (ll).
4. At the wire harness side, mea-
sure voltage between the TP
sensor 3P connector terminals
N o . 1 a n d N o . 3 .
ls there approx. 5 V?
Check tor an open in the wire
(SG2lino):
Measure voltage between ECM/
PCM connector C (31Pi terminals
C18 and C28.
Repair open in the wite betwe€n
ECM/PCM (Cl81and TP son.or.
ls there approx. 5 V?
Substitute
a known-good
ECM/
PCM and recheck. lf Pr$cribed
voltage is now aveilabl6. replace
the original ECM/PCM.