Page 409 of 2189
PGM-FI System
(From page 11-139)
Check for a shon in the HO2S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1) 4P connector.3. Start the engine and let it idle.4. Check the Primary HO2S(Sensor 1)output voltage withthe scan tool,
Does it stay at 0.1 V or less?
Check for a short in lhe wire(PHO2S linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector D ('l6P).
3. Check for continuity betweenthe Primary HO2S lsensor 1)4P connector terminal No. 1and body ground.
Repair short in lhe wire b6tw6enECM/rcM (D7) and Primary llO2S{Sensor 1}.
Substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awry, replaco theoriginal ECM/PCM.
Primary Heated Oxygen Sensor (Primary HO2S) (sensor 1l
('96 - 98 Models except Dl6Y5 engine with M/T) (cont'dl
PRIMARY HO2S lsonsor 1l ,tP CONNECTOR lC123l
Wire side of female terminals
11-140
Page 411 of 2189
PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (Sensor 1)
('99 - 00 Models except Dl6Y5 engine with M/T) (cont'd)
PRIMARY HO2S {S€oror 1} 4P CONNECTOR lc123l
PHO2S f----l,wHl_l:-f;-l
0ffi
_L
Wire side of female terminals
(From page 11 141)
Chock fo. a shori in the HO2S:1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1i 4P connector.3. Stan the engine and let it idle.4. Check the Primary HO2S(Sensor 1) output voltage withthe scan tool.
Does it stay at 0.5 V or less?Roplaco the HO2S (Sensor 1).
Check tor a short in the wire{PHO2S linel:1. Turn the ignition switch OFF.2. Disconnect the EcltI/PcM con-nector C {31P).3. Check for continuity betweenthe Primary HO2S lsensor 1)4P connector terminal No. 1and body ground.
ReDair shorl in the wi.e betweenECM/PCM (Cl61 and PrimaryHO2S (Sercor 11.
Substitute a known-good ECM/PCM and recheck. lf symptom/indication goes away, replace theoriginal ECM/PCM.
11-142
Page 416 of 2189

Check the ECM input vottage {lP-/
VS- lino):1. Turn the ignition switch OFF.
2 Turn the ignition switch ON (ll)
3. Measure voltage between
ECM connector terminals C24
Ch.ck the ECM:
1. Turn the ignition switch OFF
2. Disconndct ECM connector C
{31P){rom the ECM.
3. Check lor continuity between
body ground and ECM con
nector terminal C24
ls there more than 0.5 V?
- Repair open in the wire
betw€en ECM {C2{l and Pri-
ma.y HO2S {S€nsor 1 l.- Substitute a known-good ECM
and recheck. It symptom/indi
cation goes away. replace the
odginal ECM.
Check to. r short in the wi.e {lP-/
VS- lin6l:1. Disconnect the 8P connector
from the Primary HO2S lsen-
sor 1).2. Check tor continuity between
body ground and ECM connec-
tor terminal C24
Ropair short in the wire bstween
the Primary HO2S lsensor 1) and
ECM (C24).
Check the ECM output voltage
{VS+ linel:N4easure voltage between ECM
connectorterminals C25 and D11.
Check for a short in the wire (VS+
line):1. Turn the ignition switch OFF.
2. Disconnect ECM connector C
{31P) Irom the ECM.
3. Check {or continuity between
body ground and ECM con
nector terminal C25.
ls there mote than 0.5 V?
ECM CONNECTORS
lFrom page'11-146)c (31PlD {15P)
tP-/vs- tREolfemale termrnals
sG2(GRN/BLKI
(cont'd)
11-147
I23a68910
111213la15t6'171622
232a25272a2930
O rP-/vs-:Z taeot
,l23a55I910
1112131a151617t822
232125212AE30
0) {REDr
23a518910
l11213ta'15't6171822
2321E272A2930
[]) vs*I rwsrt
(To page 11- 148)(To page 11 148)
Page 417 of 2189

PGM-FI System
Primary Heated Oxygen Sensor (Primary HO2SI (sensor l)
(Dl6Y5 engine with M/T) (cont'd)
(From page 1l-147)(From page 11 147)
(To page 11 149)
{GRN/BLK}
(GRN/8I-K}
(To page 11-149)
11-148
Substitute a known-good ECMand rechock. tf symptom/indicr-tion goes away, replace the origi-nalECM.
Check for a short in the wire llP+lin6):1. Disconnect the 8P connectorIrom the Primary HO2S (Sen-
sor 1).2. Check tor continuity betweenbody ground and ECM connec-tor terminal C25.
Repair short in the wiro botweenthe Primarv HO2S {Sensor 1} andECM {C25}.
Replace th€ Primary HOzS {Sen-sor 11.
| 2 3ra1a9to
tl 12t516111a
p ffi;r, w''.""i0"or.I lemate lerml
ls there more than 5.0 V?check the EcM:1. Turn the ignition switch OFF.2. Disconnect the 8P connectorfrom the Primary HO2S (Sen-
sor 1).3. Turn the ignition switch ON (ll).4. Measure voltage between ECN4connector C25 and D11.
ls there more than 5.0 V?
Check the ECM input voltage llP-/vS-linel:1. Start the engine. Hold theengine at 3,000 rpm with noload (transmission in neutral)untilthe radiator fan comes on,then let it idle.2. Measure voltage between ECMconnector terminals C24 andDt1.
Subslitute a known-good ECMand rgcheck. It symptom/indica-tion goes away, repl.ce the origi-nal ECM.
ls there 2.6 2.8 V?Check th6 ECM output voltage(VS+ linel:Measure voltage between ECMconnector terminals C25 and D11.
7a9t0It 12t3t6'11ta
VS+{WHT}sG2
235
,9 ,101l12
l3'tat515
1 2i35a9t0't2'ttt5ttrl22
VS+{WHT)sG2
23
6lt9ll1315
Page 418 of 2189

(From page 11 148)(From page 11'148)
Roplac€ th€ Primary HOzS (Sen'
sor 11.ls there lessthan 2.8 V?
Substitute a known-good ECM
and recheck. lf symptom/indica'
tion goes awav, replace th€ odgi'
nalECM.
Check the ECM oulput voltage
(lP+ linel:Measure voltage between ECM
connector terminals C23 and D11
Substitute a known-good ECM
and recheck f symptom/indica-
tion goes awaY, replace the origi_
nal ECM.
ls there more than 0.4 V?
Check the ECM:1. Turn the ignition switch OFF.
2. Disconnect ECM connector C(31Plfrom the ECM.
3. Check for continuity between
body ground and ECM con-
nector terminal C23
Check fot an oPen in tha wire
llP+ linel:1. Turn the ignition switch OFF.
2. Disconnect the 8P connoctor
from the Primary HO2S (Sen-
sor'l).3. Check for continuity between
the PrimarY HO2S (Sensor 1)
8P connector terminal No. 7
and ECM connector termrnal
c23.
Repair open in the wire belween
ECM {C231 and Primary HO2S
{Sensor 11.
Substitute a known_good ECM
and r6check. lf symPlom/indica'
tion goos away, replace the odgi-
nalECM.
Check for a short in the wire llP+
line):1. Disconnect the 8P connector
from the Primary HO2S {Sen'
sor 1),2. Check for continuity between
body ground and ECM con-
nector terminal C23.
Repair short in lhe wire belween
the Primary HO2S (Sensor 'l) dnd
ECM {C23).
Replace the Primary HO2S (Sen'
sor 1).
sG2(GRN/BLKI
Wire side offemale termanals
PRIMARY HO2S(SENSOR 1l8PcoNNECTOR lC1a5l
lP+(BLK)
Wire side of
female termrnalsof femaleterminals
NO
(cont'd)
123a68910
111213141516171822
2125a30
I lP+
6) tBrK)
ECM CONNECTOR C {31P}
23a67II10
1112131l15161118,422
232a25A30
A lP+Ij/ IBLK)
11-149
Page 420 of 2189

t
The scan tool indicates Diagnostic Trouble Code (DTC) P1168; A low voltage problem in the Primary Heated
Oxygen Sensor (Primarv Ho2S) (Sensor 1) LABEL circuit'
- The MIL has b6€n reponed on'
- DTC P1168 is storcd
Problem vedfication:
1. Do the ECM Reset Procedure
2. Start the engine.
3. Wait at least two minutes
lntalmittent failure' aYstom b OK
at thi3 time. Chock lor Poor con-
nection3 or loo3o wiro3 at C145
(Primary HO2S, S.n.or 1l and
ECM.
ls DTC P1168 indicated?
Chock th. ECM:
1. Turn the ignition switch OFF.
2. Disconnect the ECM connec'
tor D 116P).3. Check for continuity between
ECM connector terminal D7
and body ground
Sub3titut. e known-good ECM
6nd r.chock. lf rymptom/indica-
tion gocr away, r.Placs the origi_
nal ECM.
Check for t shott in lhg wire3
ILABEL line):1. Disconnect the Primary HO2S
(Sensor 1) 8P connector'
2. Check for continuitv between
ECM connector terminal D7
and body ground
Reoair short in the wir63 botlvoon
lhe Primary HO2S {Sensor 1} end
ECM (O71.
ECM CONNECTOR D {16PI
LABEL {WHTI
wire side of female terminals
LABEL (WHTI
(cont'd)
Page 422 of 2189

Secondary Heated Oxygen Sensor {secondary HO2S) (Sensor 2l
*'t : D16Y8 engine*2:'99 - O0 m;dels except D16Y5 engine with M//T
The scan tool indicates Diagnostic Trouble Code (DTC) P0137: A low voltage problem in the Secondary Heated
Oxygen Sensor (Secondary HO2S) (Sensor 2) circuit'
SECONDARY HO2S ls.n.ot 2),rP CONNECTOR (C125, C782')
Wire side oI temale terminals
(cont'd)
1 1-153
- Tho MIL has been reported on- DTC P0137 is stored.
Problem verification:1. Do the ECM/PCM Reset Pro
cedure.2. Start the engine. Hold the
engine at 3,000 rpm wlth no
load (in Park or neutral) until
the radiator fan comes on
3. With the scan tool, check the
Secondary HO2S (Sensor 2)
output voltage at 3,000 rPm
lntermittent frilure, sYdem is OK
at this tim6. Check for Poor con'
nections or loolo wir.3 at C131t(locatod undor right.ido of desh)'
C432. {located under middle of
dashl, cl25 lc782lr {SecondaryHO2S) tsensor 2l .nd ECM/PCM.
Does the voltage staY at 0.3 V
or less?
Ch6ck tot a sho.t in the S€condery
HO23:'1. Turn the ignition switch OFF.
2, Disconnect the SecondarY
HO2S lSensor 2)4P connector.
3. Start the engine.
4. Check the SecondarY HO2S
lsensor 2) output with the scan
tool,
Check tor a short in the wire
{SHO2S linel:1. Turn the ignition switch OFF.
2. Discon n ect tho EcM/PCM
connector D {16P) {A (32P))*'
3. Check for continuity between
the SecondarY H02S (Sensor
2) 4P connector terminal No 1
and body ground.
R€pair short in tho wire bstwoen
ECM/PCM lD14 (A231*' | and
Secondarv HOzS (Sensor 2).
Substitute a known-good ECM/
PCM and recheck lf 3ymptom/
indicalion go€s awaY, tePltco
the oiigin.l ECM/PCM.
Page 426 of 2189

tFo135l
iPol4tl
Heated Oxygen Sensor (HO2SI Heater
('96 - 98 Mbdels,'99 - 00 Dl6Y5 engine with M/Tl
*: p0141 (To page 11-158)**: D'16Y8 engane
The scan tool indicates Diagnostrc Trouble code (DTC) P0135: An electrical probl€m in the Primary Heated
Oxygen Sensor (Primary HOiS) (Sensor 1) Heater system (Except D16Y5 engine with M/T)'
The;can tool indicates Diagnostic Trouble code (DTC) P0141: A problem in the secondary Heated oxygen sensor
(secondarv HO2S) (Sensor 2) Heater circuit.
PRIMARY HO2S (Son.or 1l aP CONNECTOR
SECoNDARY HO2S tsensor 2l ilP CONNECTORT
Terminal side of male terminals
PRIMARY HOzS (SENSOR 1) 4P CONNECTOR ICl23I
SECONDARY HO2S ISENSOR 2) 4P CONNECTOR {C125I*
PO2SHIC, SO2SHTCIBLK/WHT)
Wire side of female terminals
SECONDARY HO2S ISENSOR 2),tP CONNECTOR 1C782)'*
so2sHTC{BLK/WHT)
Wire side oI female terminals
I(cont'd)
11-157
- The MIL h.s boen Jeponed on.- DTC P0135, and/or Polal .re
stoled.
Problem verificationl
1. Do the ECM/PCM Reset Pro-
ceduae,2. Start the enginelniermittent tailura, sYttam i! OK
at thi3 time, Chsck for Poor con'
neciion3 or loose wilG3 at
C131** (locat.d undo. right sido
ot dashl, C{32** (loc.ted under
middle ol dashl, C123 (PrimarY
HO2S. Sansor 1) C125 lc782l*r
{Socondery H02S, Sonsor 2l'
and EcM/PcM.Check for an open or 3hort in tho
HO25:1. Turn the ignition switch OFF.
2. Disconnect the HO2S (Primary
or Secondary*) (Sensor 1 or
Sensor 2) 4P connector'3. At the Ho2s side, measure
resistance between the HO2S
4P connector terminals No. 3
and No.4.
ls there 10 - 40 0?
Check for continuity between
body ground and the HO2S 4P
connector terminals No. 3 and
No.4 individually
Chock for an oPen ot short in tho
wire |PO2SHTC, SO2SHTC* linol:
1. Turn the ignition switch ON (ll).
2. Measure voltage between the
HO2S 4P connector terminalsNo.3 and No.4.
(To page 11'158)