Page 216 of 1413
System Description
System Connectors [Dash and Floor]
PGM-FI MAINRELAY
C1I44 UNDEN-OASHFUSE/REALYBOX
ENGINECOMPARTMENTWIRE
DASHBOARO WIREHARNESS
MAINWIREHARI{ESS
REARWIREHARNESS
11-24
Page 218 of 1413
System Description
System Connectors [Dash and Floor] {cont'd}
UNDER-DASHFUSE/RELAYBOX
DASHBOARDHARNESS
MAINWIREHARNESS
11-26
Page 235 of 1413

Th. ll.lfunction Indicltor Lamp
lMlll at!y3 on o. cornaa on alt6ltwo aacond!.
Connect the SCS short connectorto th6 sorvice check connector(see page 11-34).
Turn the ignition switch ON.
Go to iolfdiagnostic Proceduros(se€ pago 11-34).Does the MIL indicate anv Oi-agnostic Trouble Code (DTC)?
Romove th€ SCS shon connectorlrom the service ch€ck connector.
Turn the ignition switch OFF.
Try to start the engine.
Connect the test harness betweenthe ECM and connectors (see
page 11-37).
Turn the ignition switch ON.
Measure voltage botween D4 (+ )terminal and D22 { - ) terminal.
connect the SCS shonconnector to servlcecheck connector.ls there approx. 5 V?
Ropair shon to body g.ound inBRN/WHT wire betwoon th6 ECMlD4) end sorvlco chock connocto?.Measure voltage be_tween D4 {+} terminaland body ground.
- R6pair open in BRN/WHT witobotwoon EcM lD4) and s6rv-ice chock connactor.- Repoir opon in BLK wiro bo-twoon 36rvi@ chock connectoaand G4Ol.
ls there approx. 5 V?
InsDoct ECU {ECM) 115 A) tuse inth6 undeFhood luse/relav box.
- Rsolaco ECU {ECM} (15 Allus€.- R6pair shon in YEL/WHT wilobotw6on ECU lEcMl 115 A)fuso and PGM-FI main rolay.
Remove the scs shortConnector from theservice check con-nector.
ls the luss OK?
NOTE:
a When there is no code stored, the MIL willstay on if the service check con-
nector is shorted.
a tf this svmotom is intermittent, check for:
- A loose ECM fuse (15A) in the under-hood tuse/relay box
- A loose No. 24 fuse (ACG) (ALT) ( 1 5A: B1 8B 1 engine, 2OA: B18C 1 en-
gine) in the under-dash fuse/relay box- An intermittent short in the BRN/WHT wire between the ECM (D4) and
the service check connector- An intermittent oDen in the BLK wire between the service check con-
nector and G4O1- An intermittent shon in the GRN/ORN wire between the ECM (A 13) and
the gauge assembly.- An intermittent short in the YELMHT wire between the ECM (D19) and
the MAP sensor- An intermittent short in the YEL/BLU wire between the ECM (D20) and
the TP sensor
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D4 (+)
l"oo,o'.
D22 t-l
uu,l
'NOTE: After repair, disconnect the SCS ShortConnsctor, test drive the car, and recheckthe MIL
lor a code.
(cont'd)
(To page 1 'l -44)lTo page 1 1-44)
11-43
Page 236 of 1413

(From page 1 1-43)
Inspect the No. 24ACG {ALT) (lG)(15 A: 81881 engine, 2OA:818C1 enginel fuse in the under-dash fuse/relav box.
- R.pllr .hon in BLK|rEL wlr6batr.v€qr undariair luro/Fbybox lnd FGM-FI m.in .obv.- noebco lto. 24 ACG {lG) nLT)(15 A: 81881 ongin., 2OA:Bl8Cl onein.l tu!6.
ls the fuse OK?
Turn the ignition switch ON.
Disconnect the 3P connector oteach sensor one al a time:. MAP sensor. TP sensor
Rcplaoo thg lgnlor that caur6dth. llght to Oo out.Does the MIL remain ON?
Turn the ignition switch OFF.
connect the test harness.Disconnect the "D" connectorfrom th€ ECM only, not the mainwire harness (see page 11-37).
Check tor continuity betweenbody ground and D19, O2O ter-minals,
- Bapai? rhod ro body g.ound inYEL/WHT wi.e boiwoon ECM(Dl9) .nd MAP ..n3or.- R.p!k shon to body ground inYEL/BLU wire b.lwo6n ECM(O2Ol .nd TP 3on!or.
Reconnect all tho sensor con-necrors,Reconnect the "D" connector torhe ECM.
Turn the ignition switch ON.
{To page 11-45}
System
Control Module (ECMI (cont'dl
PGM-FI
Engine
Dt9I
I oooooooooo ooo I oooooooo I omoool o oooooooooo | |I ooooooooooooo I oooooooo 1o('oe(lo I ooooooooooo | |-lD2O I
\-.J
Continuity?
(From page 11-43)
Disconnect "A" con-nector from the ECM.
Subrtltute r knowngood ECM.nd rochock. ll lymptom/indics-tlon g@a rw!y, rephco tho origi-n.l ECM.
ls the MIL ON?
Ropair short to bodygiound in GRN/ORNwir6 botwoon tho ECMlA131 6nd MlL.
11-44
Page 240 of 1413
YES
PGM-FI
Heated
11-471
System
Oxygen Sensor Heater (cont'd)
YEL/BLK I+I ORI{/BLK (-I
wire side
HO2S44 N.m{4.5 kgt.m, 33 lbf.ft}
Check for continuity to bodyground on terminals 3 and 4of theHO2S.
Check for continuity between terminal4 and terminals 1 and 2 in-dividually.
Turn the ignition switch ON.
At the HO2S harness. measurevoltage between YEL/BLK 1f lteFminal and ORN/BLK l-) ter-mrnal.
Turn the ignition switch OFF.
Disconnect the "A" connectorfrom the ECM.Measure voltage between YEL/BLK l+) terminal and bodyground.
Turn the ignition switch ON.
At HO25 harness, measure vol-tage between YEL/8LK (+) termi-nal and ORN/BLK {-) terminal.
RoDair short in ORN/BLK wir6 b6tw6on ECM(A6l and HO2S.ls there baftery voltage?
Ropai. opon in YEL/BLKwire botwoan HO2S.nd PGM-FI main relav.
Turn the ignition switch OFF.Turn the ignition switch OFF.
11-48
{To page 11-49){To page 11-49}
Page 241 of 1413
* Monitor over a 5 minute Deriod unl6ssthe current drops below O.1A im-mediatelv.
BATTERYVOLTAGE?
L-E;
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Connect the test harness "A"
connector to the main wire harness only, not the ECM (see page
1 1-371.
Connect an ammetet between ter-minals A6 {+ ) and 426 (- )
Turn the ignition switch ON.
ls the current less than0.1 A?.
Subrtitulo s known-good ECM.nd r.ch6ck. lf symptom/indica-tion goes away. roplaco tho origi-n.l ECM.
Connoct the test harn€ss "A"
connector to the main wire har-n6ss only. not th€ €CM {seo page't't-37).
Turn the ignition switch ON.
Measwe vohage bstween A6 {+ }tg.minal and A23 {-)terminal.
Ropsii op6n in ORN/BLK wiro bo-tw..n ECM {A6l and tho HO2S.
Subrtiluto s known{ood ECMlnd Echock. ll .ympiom/indic{-tirn god !way, '.pLc! f|e origl-h.l ECM.
11-49
Page 245 of 1413

Measure voltage between YEL/WHT {818C1 engine), YEL/RED(B188'1 engine) {+ ) terminal andbodv ground.
Measure voltage between YEL/WHT (818C1 engine), YEL/RED{B1881 engine) (+ } terminal andGRN/WHT (- ) terminal.
ls there approx. 5 V?
Repair opon in GRN/WHT wir6 botweonECM lD2l l and thoMAP sonsor,
Turn the ionition switch OFF.
ls there approi. 5 V?
Connect the test harness "D"
connector to the ECM only, nottothe main wire harness {see page11,37).
Turn the ignition switch ON.
Measure voltage betweon wHT/YEL (+ ) terminal and GRN/WHT{- } terminal.Measure voltage between D19{+} terminal and D21 {-}termrnat,
ls there approx. 5 V?
Bepair open in YEL/WHT wi.e be-tw€6n ECM lD19) and tho MAPaon30t.
ls there approx. 5 V?
Substitule s known-good ECMand rechock. ll symptom/indica'tion goes away, replac€ tho oiigi'nal ECM.Turn the ignition switch OFF.
Reconnecl the 3P connector tothe MAP sensor.
Connect the test harness betweenthe ECM and connector (see page1 1-371.
Turn the ignition switch ON.
11,52)
{To page 11-54}lTo page I l-54)
(cont'd)
Page 246 of 1413
PGM-FI System
Manifold Absolute Pressure
lFrom page 11-53)
{MAPI Sensor (cont'd)
(From paqe 1 1-53)
NO
M6asure voltage between D17{+) terminal and 021 (-}terminal.
ls there approx. 3 V?
Substituto 6 known{ood ECM.nd rach.ck. It symptom/indica-tion gooa away, Eplaco tho orlgi-nrl €CM.
Turn the ignition switch OFF.
Connect the test harness "D"
connector to the ECM only. not tothe main wire harness lsee page11-37).
Turn the ignition switch ON.
Measure voltage botwson Dl7(+) terminal and D21 {-}terminal.
R.p.lr opon or ahort in WHT|rELwi?o botw.on ECM {O17) and thoMAP senso..ls there approx. 5 V?
Substitute a known{ood ECMand rochsck. It prdcribed voltrgob now availablo, rophce trie origi-nal ECM.
approx. 3 v?
-D17 til D21 (-l
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11-54
'.---.-'