
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)

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

(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

PGM-FI System
IiT-"-w Heated 9{ygglSensor (primary HO2SI (Sensor 1)(Dl6Y5 engine with M/Tl lconr'd)
1T1163 Ih" scan tool indicates Diagnostic Trouble code (DTc) P1169: A high volrage probtem in the pnmary Heated- Uxygen Sensor {primary HO2S) (Sensor .l) LABEL circuit.
PSTMARY HO2S (SENSOR 1l8p CONNECTOR (145)
LABEL IWHTI
ECM CONNECTOR O {16P}
(GRN/BLK)
female
IGRN/BLKI
- The MIL hrs been reported on.- DTC Pl169 i3 stored.
Problem verification:L Do the ECM Reset Procedure.2. Start the engine.3. Wait at least two minutes.
Intormittent f.ilure, sv*em b OKat this time. Check for poor con-n.ctions or loose wires at C145(Prim.ry HO2S, Sensor 1l andECM.
ls DTC P1169 indicated?
Ch€ck Ior an op6n in th€ wire(LABEL line):1. Turn the ignition switch OFF.2. Disconnect the Primary HO2S(Sensor 1) 8P connector.3. Turn the ignition switch ON (ll).4. Measure voltage betweenPrimary HO2S lsensor 1) 8Pconnector No, 4 terminal andbody ground.
Check lor an open in the wire{SG2linel:1. Turn the ignition swilch OFF.2. Disconnect ECM connector D(16P)trom the ECM.3. Check for continuity betlveenECM connector terminal D1land Primary HO2S (Sensor 1)8P connector terminal No. 3.
ls there approx. 5 V?
Ropair opon in the wires betweonlhe P.imary HO2S {Sensor 't} andECM tD7l.
R€pair open in th6 wire betweenthe Primary HO2S lsensor 1) andECM (011).
ls there continuity?
Roplace the Primary HO2S (Sen-sor 1).
123a5
689101t12
t3141516sG2
side ofe terminalstll
II-- rl
;G2
I2
6
34
8
11-152

PGM-FI System
I
a
a
9ggoqOfry Heated Oxygen Sensor (Secondary HO2S) {sensor 2l('96 - 98 Models; '99 - 00 D16YS engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) PO'138: A high voltag€ problem in the Secondary HeatedOxygen Sensor (Secondary HO2SI (sensor 2) circuit.
SECONDARY HO2S ls.nsor 2l4P CONNECTOR C125 tc782t*
JUMPER WIRE
sHo2sIWHT/RED}
sHo2sG(RED/YEL)(GRN/WHT)*(GRN/BLK)*'
Wire side of female terminals
ECM/FCM CONN€CTOR D Il6PI
sH()2sG{YEL/RED){GRN/BLK}'
JUMPER WINE
Wire side of female terminals
'i D16Yg engine*1i Dl6Y5 engine
- Ths MIL ha3 bcen r6port.d on.- DTC m138 i. 3tored.
Problem vorilication:1. Do the ECM/PCM Reset Pro-cedure.2. Start the engine. Hold theengine at 3.000 rpm with noload (in Park or neutral) untilthe radiatorfan comes on.3. With the scan tool, ch€cktheSecondary HO2S {Sensor 2)outputvoltageat 3,000rpm.
Into.mittant failurc, sy3tem b OKrt thi3 tims. Ch6ck tor poor con-n6clionr or loo3€ wiroa at C13'l*(locat d und6r right lido of dr'h),C/€2r (loc.tod und€r middle old.rhl, C125 {C782lr (Socond.ryHO2S S6n3or 2) .nd ECM/PCM.
Chcd( for rn open in the Socond!ryf|o2s:1. Turn the ignition switch OFF.2. Disconnect the SecondaryHO2S (Sensor 2) 4P connector.3. Connect the Secondary HO2S(Sensor 2) 4P connector ter-minals No. 1 and No.2 with aJUmper wire.4. Tu.n the ignition switch ON (ll).5. Chock the Secondary HO2S(Sensor 2) output vollage withthe scan tool.
ls there 0.6 V or more?
Check tor an open in the wiro(SHO2S lin6l:1. Turn th6 ignition switch OFF.2. Connect ECM/PCM connectorterminals D14 and D13 with ajumper wire.3. Turn the ignition switch ON {ll}.4. Check the Secondary HO2S(Sensor 2) oltput voltagewith the scan tool.
Rapair op.n in the wiio botw.onECM/PCM lD13 and/or Dlal andS.cond.ry HO2S ls€nsor 21.
ls thore 0.6 V or more?
Subslituto a known-good ECM/PCM .nd rccheck. lt symptom/indication goe! rway, replacethe original ECM/PCM.
11-154

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)

PGM-FI System
a
a
Heated Oxygen Sensor (HO2S) Heater
('96 - 98 Models,'99 - 00 D16Y5 engine with M/T) (cont'dl
PRIMARY HO2S {SENSOR 1I 4P CONNECTOR{c1231SECONDARY HO2S {SENSOR 2} 4PcoNNECTOR 1C125)r
r-l --'1
ll i2l
f;T;ttcl|BLK/ &)YELI Y
Wire side of fomale lerminals
SECONDARY HO2SISENSOR 2) 4P CONNECTOR{c78ilf
IBLK/WHT)
Wire side of lemale terminals
(From page 11-157)
Wire sid€ ot temale terminals
SO2HTC(BLK/WHTI* PO2SHTC{BLK/WHTI
*: P0141*+: Dl6Y8 engine
11-158
(From page 11-157)
Check tor an op6n or 3hoft in thewire {lGl lin6):Measure voltage between theHO2S 4P connector terminals No.3(D16Y8 engine: No. 4) and bodyground.- Repair open or shon in thewire between Primary HO2Slson.or 1), {No. 15 ALTERNA-TOR SP SENSORI (7.5 Al fuseand Secondary HO2S, Sonsol2t,.- Replace the No. 15 ALTERNA-TOR SP SENSOR 17.5 A) tuse.Check for an open in the wireIPO2SHTC, SO2SHTC' linel:1. Turn the ignition switch OFF.2. Reconnect the HO2S 4P con-nector.3. Disconnect the ECM/PCM con-nector A (32P).
4. Turn the ignition switch ON (ll).
5. Measure voltage between theECM,/PCM connector terminals46 and 410 {A5 and A10)*.
Ropail opan in the wire b€twoenECM/PCM lA6, A5l* and HO2S{Primary, Secondary+1.
ls there 0.1 V or less?
Substitute a known-good ECM/PCM and recheck. ll symptom/indication goes awry, repbcetho origin.l ECM/PCM.
ECM/PCM CONNECTOR A I32P)
so2sHrc ItBLK/WH0.J
pozsxtc E/
IBI-K/WHTI ^,-----{v}-|.=,|I
PG1IBLK}3u I JsTgT roll12r3t5t6Ittar920z2l 2321
25272A2i3o
Check tor a short in the wire{PO2SHTC. SO2SHTC* line):'1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector A (32P1.
3. Check for continuity betweenthe ECM/PCM connector termi-nal 46 (A5)* and body ground.
Repair short in thg wire betwe€nECM/PCM lA6, A5*l .nd HO2S(P.im.ry, Socondary*).
Substitute a known-good ECM/PCM and recheck. It symptom/indicetion goes away, rophcethe original ECM/PCM.

IHeated Oxygen Sensor (HO2S) Heater
i'ss - oo Mb-dels except D16Y5 engine with M/Tl
The scan toot indicates Diagnostic Trouble Code (DTC) P0135: An electrical problem in the Primary Heated
Oxygen Sensor (Primary ttOiS) (Sensor 1) Heater system {Except D15Y5 engine with M/T)'
The
-scan tool indicates Diagnostic Trouble Code (DTC) P0141; A problem in the Secondary Heated Oigen Sensor
(Secondarv HO2S) {Sensor 2) Heater circuit
Fo13sl
Fol11l
lntermiftent failuro, sYstom b OK
at thit limo. Ch6ck lor Poor oon'
nectiont or looso wita! at
C131'* {loc.tod und.t right ido
ol drshl, C432'* (located undel
middlo of dashl, C123 (PrimarY
HOzS, Sensor 1) C125 (Ct82lr'
(socondary HO2S, Sensor 2)t
.nd ECM/PCM.
PRIMAFY HO2S ls.n.or ll rrP CONNECTOR
SECOITIDARY HO2S (Srn.ol21 4P CONNECTOR'
Terminal side of male terminals
PRIMARY HO2S {SENSOR 1} ilP @NI{ECTOR lc123l
sEcoNDARY HO2S ISENSOR 2) aP @NNECTOR (C125)'
3l-, l-tl-t Fo2sHrc. so2sHrc
ver.t l ^-1 .'l {BLK/wHrl
11 '!'l-l
| --=- Iu----{v)'---..-'
Wire side of {emale terminals
SECO'TIDARY Ho2S (SENSOR 2,
4P CONNESTOR {C7&llt'
so2sHTc(BLKnflHTlIBLK/WHT)
(cont'd)
1 1-159
Wire side oI female terminals
r: p0141 {To page 11-160}**: D16Yg engine
- The MIL has been reponed on.- DTC P0135. and/or P0141 are
storod.
Problem vorification:1. Do the ECM/PCM Reset Pro-
cedute.2. Stan the englne.
Chock foi an open or short in the
HO25:1. Turn the ignition switch OFF
2. Disconnect the HO2S (Primary
or Secondary*) lSensor 1 or
Sensor 2) 4P connector'
3. At the H02S side, measure
resistance between the HO2S
4P connector terminals No. 3
and No.4.
ls there 10 - 40 n?
Check for continuity between
body ground and the HO2S 4P
connector terminals No. 3 and
No.4 individuallY.
Check for an opon or short in lho
wire (PO2SHTC, SO2SHTC+ line):'1. Turn the ignition switch ON (ll).
2. Measure voltage between the
H02S 4P connector termlnalsNo.3 and No.4.
{To page 11-160}