Troubleshooting
Troubleshooting Procedures
How To Begin Troubleshooting
When the Malfunction indicator Lamp (MlLl has been reported on, or there is a driveability problem, use the appropri-ate procedure below to diagnose and repair the problem.
A. When the MIL has come on:
1. Connect the Honda PGM Tester or an OBD Il scan tool to the 16P Data Link Connector (DLC) located behind theright side of the center console.
Turn the ignition switch ON (ll).
Check the DTC and note it. Also check and note
the freeze frame data.
Refer to the Diagnostic Trouble Code Chart and
begin troubleshooting.
NOTE:
. SeetheOBDll scan tool or Honda PGM Tester user's manuals for specific operating instructions.. The scan tool or tester can read the Diagnostic Trouble Codes (DTC), freeze frame data, current data, and otherEngine Control Module (ECM}/Powertrain Control Module (PCM) data.. Freeze frame data indicates the engine conditions when the first malfunction, misfire or fuel trim malfunction wasdetected. lt can be useful information when troubleshootino.
B. When the MIL has not come on, but there is a driveability problem, refer to the Symptom Chart on page 11-64.
C. DTCs will be indicated by the blinking of the Malfunction Indicator Lamp {MlL) with the SCS service connector con-nected.
Connect the SCS service connector to Service Check Connector as shown. {The 2P Service Check Connecror rslocated behind the right side of the center console.) Turn the ignition switch ON 0l).
DATA LINK CONNECTOR I16PI
1 1-60
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ll. Engine Controt Module (EcM)/Powertrain Control Module {PCM) Reset Procedure
Either of the following actions will reset the ECM/PCM.
. use the oBD ll scan tool or Honda PGM Tester to clear the ECM' s/PCM' s memory. (see the oBD ll scan tool or
Honda PGM Tester user's manuals for specific operating instructions )
. Turn the ignition switch oFF. Remove the BACK UP (RADIO) (7.5 A) fuse from the under-hood fuse/relay box for 10
seconos.
lll. Final Procedure {this procedure must be done after any troubleshooting)
1. Remove the SCS Service Connector if it is connected. lf the SCS service connector is connected. and there are no
DTCS stored in the ECM/PCM, the MIL will stay on when the ignition switch is turnsd oN (ll).
2. Do the ECM/PCM Reset Procedure.
3. Turn the ignition switch OFF
4. Disconnect the OBD ll scan tool orHonda PGM Tester from the Data Link Connector ( 16P)'
(cont'd)
1 1-61
BACK UP {RADIOI I7,5 AI FUSE
FUSE/RELAY BOX
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Troubleshooting
Troubleshooting Procedures (cont'd)
lf the inspection for a particular code requires voltage or resistance checks at the EcM/pcM connectors, remove the rightkick panel. Unbolt the EcM/PcM. and connect the backprobe sets and a digital multimeter as described below, check thesystem according to the procedure described for the appropriate code(s) listed on the following pages.
How to Us6 tho Backprobe S6ts
Backp.obo Adapto.
BACKPROBE SET
connect the backprobe adapters to the stacking patch cords. and connect the cords to a multimeter. Using the wire insula-tion as a guide for the contoured tip of the backprobe adapter, gently slide the tip into the connector from the wire sideuntil it comes in contact with the terminal end of the wire.
DIGITAI. MULTIMETER(Commarci.lly rvrilabl.l orKS-AHM-32-@3
@@)@)c,
11-62
o'SAZ - (xtlqDA lTwo requir.dl
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ECM/PCM Data
By connecting the OBD ll scan tool or the Honda PGM Tester to the 16P data link connector (OLC), various data can be
retrieved from the ECM/PCM. The items listed in the table below conform to the SAE recommended practice
The Honda PGM Tester also reads data beyond that recommended by SAE.
understanding this data will help to find the causes of intermittent failures or engine problems.
NOTE:
The ',operating values" given below are approximate values and may be different depending on the environment and
the individual vehicle.
Unless noted otherwise. "at idle speed" means idling with the engine completely warmed up, transmission in position
Park or neutral and the A,./C and all accessories turned otf.
DataDesc.iptionOp€rating ValuoFreeze Data
Diagnostic
Trouble Code
(DTC)
lf the ECM/PCM detects a problem, it will store it as a
code consisting of one letter and tour numbers
Depending on the problem, an SAE-defined code (Poxxx)
or a Honda-defined code (P'lxxx) will be output to the
tester.
lf no problem is detected,
there is no output.
YES
Engine SpeedThe ECN4/PCN4 computes engine speed from the signals
sent from the Crankshaft Position sensor.
This data is used for determining the time and amount of
fuel iniection.
Nearly the same as
tachometer indication
At idle speed:'97 - 98 models:
750 t 50 rpm'99 - 00 models:
730 f 50 rpm
YES
Vehicle SpeedThe ECM/PCM converts pulse signals from the Vehicle
Speed Sensor (VSSI into speed data.
Nearly the same as
speedometer indicationYES
Manifold
Absolute
Pressure (MAP)
The absolute pressure caused in the intake manifold by
engine load and speed.
With engin6 stopped:
Nearly the same as atmo-
spheric pressure
At idle speed:
2a - 41 kPa {210 - 310
mmHg, 8.3 - 12.2 inHg)
YES
Engine Coolant
Temperature
{ECT)
The ECT sensor converts coolant temperature into volt-
age and signals the ECM/PCM. The sensor is a thermistor
whose internal resistance changes with coolant tempera-
ture. The ECM/PCM uses the voltage signals from the
ECT sensor to determine the amount of injected fuel
With cold engine:
Same as ambient temPer-
ature and IAT
With engine warmed uP:
approx. 163 - 2'12'F
(73 - 100"c)
YES
Heated Oxygen
Sensor (HO25)
(Primary,
Sensor 1)
(Secondary
Sensor 2)
The Heated Oxygen Sensor detects the oxygen content in
the exhaust gas and sends voltage signals to the
ECMiPCM. Based on these signals, the ECM/PCM controls
the airlfuel ratio. When the oxygen content is high (that is.
when the ratio is leaner than the stoichiometric ratio), the
voltage signal is lower.
When the orygen content is low (that is, when the ratio
is richer than the stoichiometric ratio), the voltage signal
is higher.
0.0 - 1.25 V
At idle speed:
about 0.1 - 0.9
NO
(cont'd)
1 1-65
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Troubleshooting
Troubleshooting Procedures (cont'd)
DataDescliptionOperating ValueFreezo Data
HO2S
Feedback
Loop Status
Loop status is indicated as "open" or "closed".
Closed: Based on the HO2S output, the ECM/pCM deter-mines the airlfuel ratio and controls the amount ofinjected fuel.
Open: ignoring HO2S output, the ECM/pCiM refers to sig,nals from the TP, MAP, and ECT sensors to control theamount of injected fuel.
At idle speed: closed
YES
Short Term
Fuel Trim
The airlfuel ratio correction coefficient for correcting theamount of injected fuel when HO2S feedback is in theclosed loop status. When the signal from the HO2S isweak, short term fuel trim gets higher, and the ECM/PCMincreases the amount of injected fuel. The airlfuel ratiogradually gets richer, causing a higher HO2S output.Consequently. the short term fuel trim is lowered. andthe ECM/PCM reduces the amount of injected fuel.This cycle keeps the airfuel ratio close to the stoichio-metric ratio when in closed looD status.
t:20y"
YES
Long Term
Fuel Trim
Long term fuel trim is computed from shon term fueltrim and indicates changes occuring in the fuel supplysystem over a long period.
lf long term fuel trim is higher than 1,00. the amount ofinjected fuel must be increased. lf it is lower than L00.the amount of injected fuel must be reduced.
! 20%
Intake Air
Temperature
(IAT)
The IAT sensor converts intake air temperature into volt-age and signals the ECrU/PCM. When intake air tempera-ture is low, the internal resistance of the sensorincreases, and the voltage signal is higher.
With cold engine:
Same as ambient temper-
ature and ECTYES
Throttle
Position
Based on the accelerator pedal position, the openingangle of the throttle valve is indicateo.At idle speed:
approx. 10%
lgnition
Timing
lgnition timing is the ignition advance angle set by theECM/PCM. The ECM/PCM matches ignition timing to thedriving conditions.
At idle speed: 16'1 4.
BTDC with the SCS ser-
vtce connector connected.
NO
Calculated
Load Value(cLV)
CLV is the engine load calculated from the MAp data.At idle speed:
2A - 410/o
At 2,500 rpm with no load:
13 - 260/o
YES
_
1 1_66
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Powertrain Control Module Terminal Arrangement -'97 Model
FCM CONNECTOR A (32P)NOTE: Standard battery voltage is 12 V.
Wire side of lemale terminals
f€rminalnumlreJWirecolor
Telminalnama
DescriptionSignal
YELlNJ4 (No.4 FUELINJECTOR)Drives No. 4 {uel injector.With engine running: duty controlled
2BLUlNJ3 (No.3 FUELINJECTOR)Drives No. 3luel injector.
REDlNJ2 {No.2 FUELINJECTOR)Drives No.2 tuel injector.
BRNlNJl (No. l FUELINJECTOR)Drives No. 1 fuel injector.
5BLK WHTSO2SHIC (SECONDARY
HEATED OXYGEN SENSOR HEATER CONTROL)
D ves secondary heated oxygensensor heater.With ignition switch ON {ll): battery voltageWith fully warmed up engino running: dutycontrolled
6BLKAr'YHT
PO2SHTC (PRIMARY
HEATED OXYGENSENSOR HEATERCONTROL}
Drives primary heated oxygensensor heater,With ignition switch ON lll): battery voltagewith fully warmed up engine running: dutycontroll6d
I8RN/BLKLGl (LOGIC GROUND}Ground forthe PCM control circuit.Less than 1.0 V at all times
10BLKPG1 lPOWER GROUND}Ground for the PCM power circuit.
l1YEUELKIGPl lPOWER SOURCE}Power source for the PCM controlcircuit.
With ignition switch ON (ll): battery voltageWith ignition switch OFF: 0 V
12BLI(BLUIACV {IDLE AIRCONTROL VALVE}Drives IACV.With €ngine running: duty controlled
REDryEL
PCS (EVAP PURGECONTFOL SOLENOIDVALVE)
Drives EVAP purge controlsolenoid valve.
With engine running, engine coolantbelow 154'F (68"C): battery voltageWith engine running, engine coolantabove 154"F (68"C): duty controlled
16GRN/VELFLR (FUEL PUMP RELAY)Drives Iuel pump relay.0 V for two seconds after turning ignition
switch ON lll), then battery voltage
118LI(REDACC (A,/C CLUTCHRELAY}Drives Ay'C clutch relay.With comoressor ON: 0 VWith compressor OFF: baftery voltage
18GRN/ORNMIL (MALFUNCTION
INDICATOR LAMP}Drives MlL.With MIL turned ON: 0 VWith MIL turned OFF: baftery voltage
19*WHT/GRNALTC (ALTERNATOR
CONTROL}Sends alternator control signal.With tully warmed-up engine running:
battery voltageDuring driving with smallelectrical load:0 '
20YEUGRNICM (IGNITION CONTROLMODULE)Sends ignition pulse.With ignition switch ON (ll): baftery voltageWith engine running: pulses
22BRN/BLKLG2 (LOGIC GROUND}Ground tor the PCM control circuit.Less than 1.0 V at alltimes
23BLKPG2 {POWER GROUND}Ground lor the PCM power circuit.
24YEUBLKIGP2 {POWER SOURCE}Power source for the PCM controlcircuit.
With ignition switch ON (ll): battery voltage
With engine switch OFF: 0 V
27GRNFANC (RADIATOR FANCONTROL)Drives radiator {an relay.With radiator fan running: 0 VWith radiator fan stopped: baftery voltage
*: USA
{cont'd)
11-67
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Troubleshooting
PCM CONNECTOR B I25PI
Powertrain Control Module Terminal Arrangement -'97 Model (cont'dl
Wire side of female terminalsPCM CONNECTOR B I25P}NOTE: Standard battery voltage is l2 V.
1 1-68L
TerminelnumbercolorTerminalnameOescriptionSignal
1LS 1A/T CLUTCHPRESSURE CONTROLSOLENOID VALVE -)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll): duty con-trolled
2REDLS + (A"/T CLUTCHPRESSURE CONTROLSOLENOID VALVE +)
Drives A,/T clutch pressure controlsolenoid valveWith ignition switch ON (ll)r duty controlled
38LU//EL
SHA (SHIFT CONTROLSOLENOID VALVE A)Drives shift control solenoid valve A.In 2nd, R position. in 2nd and 3rd gear inD4, D3 position: Battery voltageIn lst gear in D4, D3 position, in 4th gear
in D4 position: 0 V
4GRN/BLKLC B (LOCK-UP CONTFOLSOLENOID VALVE B)Drives lock-up control solenoidvalve B,With full lock-up; Baftery voltageWith half lock-up: duty controlled
5YELLC A (LOCK.UP CONTROLSOLENOID VALVE A)Drives lock-up control solenoidWith lock'up ON: battery voltageWith lock-up OFF:0 V
IPNKATPD3 (Ay'T GEARPOSITION SWITCH}Detects A/T gear position switchsignal. _
In D3 position:0 Vln any other position: battery voltage
11GRN/VVHT
SHB (SHIFT CONTROLSOLENOID VALVE 8}Drives shift control solenoid valve B.In 1st, 2nd position, in 1st and 2nd gear inD4, D3 position: Battery voltageIn R position, ;n 3rd gear in 04, D3, in 4thgear in D4 position: 0 V
12WHT/BEDILU (INTERLOCK
CONTROL UNITiDetects interlock control unh signal.With ignition switch ON (ll)and brakepedal depressed: battery voltage
GRN/BLKD4IND (04 INDICATORLIGHT}Drives Dl indicator light.With D4 indicator light turned ON: batteryvoltageWith D4 indicator light turned OFF: 0 V
14NMSG (MAINSHAFT
SPEED SENSOR GROUND}Ground tor mainshaft speed sensor.
REDNM (MAINSHAFT SPEEDSENSOR)Detects mainshaft speed sensorsrgnal,With engine running: pulses
16ATPR (A"/T GEARPOSITION SWITCH)Detects A/T gear position switchsrgnal.InRposition:0VIn any other position: battery voltage
1'lBLUATP2 (A./T GEARPOSITION SWITCH)Detects A/T gear position switchsrg nal,In 2nd position: 0 VIn any other position: battery voltage
18BRNATP1 (4,,/T GEARPOSTTTON SWTTCH)Detects A/T gear position switchsrg nal,ln lst position: 0 VIn any other position: battery voltage
22GBNNCSG (COUNTERSHAFT
SPEED SENSOR GROUND)Ground tor countershaft speedsensor,
23BLUNC (COUNTERSHAFT
SPEED SENSOR)Detects countershaft speed sensorsrgnal.With agnition switch ON (ll), and lrontwheels rotating: pulses
24YELATPD4 (M GEARPOSITION SWITCH)Detects A,/T gear position switchsrgnal.In D4 positionr 0 VIn any other position: battery voltage
25LT GRNATPNP {A/T GEARPOSITION SWITCH)Detects A/T gear position switchsignal.In park or neutral:0 VIn any other position: about 5 V
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PCM CONNECTOR C (31PI
ferminalnumberWirecolorTerminalnameDoscriptionSignal
'tBLUiREDCKFP (CKF SENSOR PSIDE)Detects CKF sensor.With engine running: pulses
2BLUCKPP (CKP SENSOR PSIDE)Detects CKP sensor.With engine running: pulses
3GRNTDCP (TDC SENSOR PSIDE)Detects TDC sensor.With engine running: pulses
4YELCYPP (CYP SENSOR PSIDE)Detects cYP sensor.With engine running: pulses
5BLU,frEDACS (A/C SWTTCHSIGNAL)Detects A,/C switch signal.With AJC switch ON: 0 VWith A,/C switch OFF: battery voltage
BLU/ORNSTS (STARTER SWITCHSIGNAL)
Detects starter switch signal.With starter switch ON (lll): bafteryvoltageWith staner switch OFF: 0 V
7BRNSCS (SERVICE CHECKSIGNAL)
Detects service check connectorsignal (the signal causing a DTCindication)
With the connector connected: 0 V
With the connector disconnected: about
5 V or battery voltage
8LT BLUK-LINESends and receives scan toolsrgnal.With ignition switch ON (ll): pulses
10WHT/BLUVBUUP)
(VOLTAGE BACKPower source tor the PCMcontrol circuit. Power source for
the DTC memory
Battery voltage at all times
11WHT/REDCKFM (CKF SENSOR MSIDE)Ground for CKF sensor signal.
12WHTCKPM (CKP SENSOR I\4SIDE)Ground lor CKP sensor signal.
13REDTDCM (TDC SENSOR MSIDE}Ground for TDC sensor signal.
14BLKCYPM (CKP SENSOR MSIDE}Ground for CYP sensor signal.
16GRN
PSPSW (P/S PRESSUREswtTcH)Detects PSP switch signal.At idle with steering wheel in straightahead position:0 VAt idle with steering wheel at full lock:
battery voltage
17WHT/REDALTF (ALTERNATOR FRSIGNAL)
Detects alternator FR signal.With fully warmed up engine running:
0 V-battery voltage {depending onelectrical load)
18BLUA/VHTVSS (VEHICLE SPEEDSENSOR)Detects VSS signal.Wirh ignition switch ON (ll) and frontwheels rotating: cycles 0 V - 5 V or bat-tery voltage
Wire side of femaie terminalsPCM CONNECTOR C {31PINOTE: Standard battery voltage is 12 V.
(cont'd)
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