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THROTTLE POS (ABSOLUTE THROTTLE POSITION, %)
When throttle position sensor is fully closed position, throttle opening is indicated as 0% and 100% full open
position.
OXYGEN SENSOR B1 S1 (HEATED OXYGEN SENSOR-1, V)
It indicates output voltage of HO2S-1 installed on exhaust manifold (pre-catalyst).
OXYGEN SENSOR B1 S2 (HEATED OXYGEN SENSOR-2, V)
It indicates output voltage of HO2S-2 installed on exhaust pipe (post-catalyst). It is used to detect catalyst dete-
rioration.
DESIRED IDLE (DESIRED IDLE SPEED, rpm)
The Desired Idle Speed is an ECM internal parameter which indicates the ECM requested idle. If the engine is
not running, this number is not valid.
TP SENSOR VOLT (THROTTLE POSITION SENSOR OUTPUT VOLTAGE, V)
The Throttle Position Sensor reading provides throttle valve opening information in the form of voltage.
INJ PULSE WIDTH (FUEL INJECTION PULSE WIDTH, msec.)
This parameter indicates time of the injector drive (valve opening) pulse which is output from ECM (but injector
drive time of NO.1 cylinder for multiport fuel injection).
IAC FLOW DUTY (IDLE AIR (SPEED) CONTROL DUTY, %)
This parameter indicates current flow time rate within a certain set cycle of IAC valve (valve opening rate) which
controls the amount of bypass air (idle speed).
TOTAL FUEL TRIM (%)
The value of Total Fuel Trim is obtained by putting values of short Term Fuel Trim and Long Term Fuel Trim
together. This value indicates how much correction is necessary to keep the air / fuel mixture stoichiometrical.
BATTERY VOLTAGE (V)
This parameter indicates battery positive voltage inputted from main relay to ECM.
CANIST PURGE DUTY (EVAP CANISTER PURGE FLOW DUTY, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP purge solenoid
valve which controls the amount of EVAP purge.
0% means that the purge valve is completely closed while 100% is a fully open valve.
CLOSED THROTTLE POSITION (ON / OFF)
This parameter will read ON when throttle valve is fully closed, or OFF when the throttle is not fully closed.
FUEL CUT (ON / OFF)
ON : Fuel being cut (output signal to injector is stopped)
OFF : Fuel not being cut
A/C CONDENSER FAN (A/C CONDENSER FAN RELAY, ON / OFF)
ON : Command for condenser fan relay operation being output.
OFF : Command for relay operation not being output.
ELECTRIC LOAD (ON / OFF)
ON : Headlight, small light, heater fan or rear window defogger ON signal inputted.
OFF : Above electric loads all turned OFF.
A/C SWITCH (ON / OFF)
ON : Command for A/C operation being output from ECM to A/C amplifier.
OFF : Command for A/C operation not being output.
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ECM TERMINAL VOLTAGE VALUES TABLE
For TYPE A (See NOTE)
NOTE:
Type A is other than follows.
Type B is left hand steering vehicle equipped with fasten seat belt light and EGR valve or right hand
steering vehicle equipped with fasten seat belt light and immobilizer control system.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E191Ground––
2Ground––
3Ground––
4 EVAP canister purge valve 10 – 14 V Ignition switch ON
5Power steering pressure switch
(if equipped)0 – 1.3 VWhile engine running at idle speed, turn
steering wheel to right or left as far as it
stops
10 – 14 V Ignition switch ON
6 Idle air control valve 0 – 13 VAt specified idle speed after engine
warmed up
7 Heater of HO2S-1 10 – 14 V Ignition switch ON
8 Fuel injector NO.4 10 – 14 V Ignition switch ON
9 Fuel injector NO.1 10 – 14 V Ignition switch ON
10 Sensor ground––
11 Camshaft position sensor0 – 0.8 V and
4 – 6 VIgnition switch ON
12–– –
13Heater oxygen sensor-1 Refer to DTC P0130 diag. flow table
CO adjusting resistor (w/o HO2S) 0 – 5 V Ignition switch ON position
14
Engine coolant temp. sensor 0.55 - 0.95 VIgnition switch ON
Engine coolant temp. : 80 °C (176 °F)
15
Intake air temp. sensor 2.0 – 2.7 VIgnition switch ON
Intake air temp. : 20 °C (68 °F)
16 Throttle opening signal0.2 – 1.0 VIgnition switch ON position and throttle
valve at idle position
2.8 – 4.8 VIgnition switch ON position and throttle
valve fully open
17EGR valve (stepper motor coil 3, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
18EGR valve (stepper motor coil 1, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensors 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor0 – 0.8 or
4 – 5 VIgnition switch ON position
24–– –
25 Knock sensor About 2.5 VAt specified idle speed after engine
warmed up
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For TYPE B (See NOTE)
E1926 Manifold absolute pressure sensor 3.3 – 4.0 VIgnition switch ON
Barometric pressure : 100 kPa
(760 mmHg)
27 A/C evaporator temp. sensor 2.0 – 2.3 VIgnition switch ON A/C evaporation temp.
sensor at 25 °C (77 °F)
28EGR valve (stepper motor coil 4, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
29EGR valve (stepper motor coil 2, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
30–– –
31 Fuel injector NO.3 10 – 14 V Ignition switch ON TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E191 Ground––
2 Ground––
3 Ground––
4 EVAP canister purge valve 10 – 14 V Ignition switch ON
5Power steering pressure switch
(if equipped)0 – 1.3 VWhile engine running at idle speed, turn
steering wheel to right or left as far as it
stops
10 – 14 V Ignition switch ON
6 Idle air control valve 0 – 13 VAt specified idle speed after engine
warmed up
7 Heater of HO2S-1 10 – 14 V Ignition switch ON
8 Fuel injector NO.4 10 – 14 V Ignition switch ON
9 Fuel injector NO.1 10 – 14 V Ignition switch ON
10 Sensor ground––
11 Camshaft position sensor0 – 0.8 V and
4 – 6 VIgnition switch ON
12–– –
13Heater oxygen sensor-1 Refer to DTC P0130 diag. flow table
CO adjusting resistor (w/o HO2S) 0 – 5 V Ignition switch ON position
14 Engine coolant temp. sensor 0.55 - 0.95 VIgnition switch ON
Engine coolant temp. : 80 °C (176 °F)
15 Intake air temp. sensor 2.0 – 2.7 VIgnition switch ON
Intake air temp. : 20 °C (68 °F)
16 Throttle opening signal0.2 – 1.0 VIgnition switch ON position and throttle
valve at idle position
2.8 – 4.8 VIgnition switch ON position and throttle
valve fully open
17EGR valve (stepper motor coil 3, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
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For TYPE A (See NOTE)
E1918EGR valve (stepper motor coil 1, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
19 Ignition coil #2––
20 Ignition coil #1––
21 Fuel injector NO.2 10 – 14 V Ignition switch ON
22 Power source for sensors 4.75 – 5.25 V Ignition switch ON
23 Crankshaft position sensor0 – 0.8 or
4 – 5 VIgnition switch ON position
24–– –
25 Knock sensor About 2.5 VAt specified idle speed after engine
warmed up
26 Manifold absolute pressure sensor 3.3 – 4.0 VIgnition switch ON
Barometric pressure : 100 kPa
(760 mmHg)
27–– –
28EGR valve (stepper motor coil 4, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
29EGR valve (stepper motor coil 2, if
equipped)10 – 14 VIgnition switch ON position leaving engine
OFF
30–– –
31 Fuel injector NO.3 10 – 14 V Ignition switch ON TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
NOTE:
See NOTE in “ECM TERMINAL VOLTAGE VALUES TABLE” for applicable model.
TERMINAL
NO.CIRCUIT NORMAL
VOLTAGECONDITION
E181 A/C compressor clutch 0 V Ignition switch ON
2 Malfunction indicator lamp10 – 14 V Engine running
0 – 1.0 V Ignition switch ON leaving engine OFF
3 Data link connector 10 – 14 V Ignition switch ON
4 Heater of HO2S-2 (if equipped) 10 – 14 V Ignition switch ON
5 Power source 10 – 14 V Ignition switch ON
6 Power source 10 – 14 V Ignition switch ON
7 Power source for buck-up 10 – 14 V Ignition switch ON and OFF
8Immobilizer indicator lamp
(with immobilizer indicator lamp)10 – 14 V Engine running
0 – 1.0 V Ignition switch ON leaving engine OFF
Duty output terminal (without
immobilizer indicator lamp)0 – 1.0 V Ignition switch ON
9–– –
10 Main relay10 – 14 V Ignition switch OFF
0.4 – 1.5 V Ignition switch ON
11 Tachometer––
12 Data link connector 4 – 5 V Ignition switch ON
13 Heated oxygen sensor-2 Refer to DTC P0130 diag. flow table
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Resistance Check
1) Disconnect ECM couplers (1) from ECM with ignition switch
OFF.
2) Check resistance between each terminal of couplers discon-
nected. CAUTION:
Never touch terminals of ECM itself or connect voltmeter
or ohmmeter (2).
CAUTION:
Be sure to connect ohmmeter probe from wire harness
side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table below represents that when parts
temperature is 20 °C (68 °F).
1. ECM coupler disconnected
2. Ohmmeter
TERMINALS CIRCUIT STANDARD RESISTANCE
E19-7 to E17-9
(For TYPE A) (See NOTE)HO2S-1 heater 5 – 6.4 Ω
E19-7 to E18-11
(For TYPE B) (See NOTE)
E18-4 to E17-9
(For TYPE A) (See NOTE)HO2S-2 heater 11.7 – 14.3 Ω
E19-9 to E19-2 No.1 injector 12.0 – 13.0 Ω
E19-21 to E19-2 No.2 injector 12.0 – 13.0 Ω
E19-31 to E19-2 No.3 injector 12.0 – 13.0 Ω
E19-8 to E19-2 No.4 injector 12.0 – 13.0 Ω
E19-28 to E19-2 EGR valve (stepper motor coil 4) 20 – 24 Ω
E19-17 to E19-2 EGR valve (stepper motor coil 3) 20 – 24 Ω
E19-29 to E19-2 EGR valve (stepper motor coil 2) 20 – 24 Ω
E19-18 to E19-2 EGR valve (stepper motor coil 1) 20 – 24 Ω
E19-4 to E19-2 EVAP canister purge valve 30 – 34 Ω
E18-19 to E17-9 (For
TYPE A) (See NOTE)Fuel pump relay 70 – 110 Ω
E18-19 to E18-11 (For
TYPE B) (See NOTE)
E18-1 to Body ground A/C compressor clutch 3 – 4.5 Ω
E18-18 to E19-2 A/C condenser fan control relay 70 – 110 Ω
E18-10 to E18-7 Main relay 70 – 110 Ω
E19-1 to Body ground Ground Continuity
E19-2 to Body ground Ground Continuity
E19-3 to Body ground Ground Continuity
NOTE:
For TYPE A and TYPE B, refer to the NOTE in “ECM Terminal Voltage Values Table” for applicable
model.
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Component Location
NOTE:
The figure shows left-hand steering vehicle.
For right-hand steering vehicle, parts with (*) are installed at the other side.
1. IAT sensor a : Immobilizer indicator lamp (if equipped) A : ECM
2. TP sensor b : A/C condenser fan motor relay (if equipped) B : A/T control module
3. Monitor connector c : Main relay C : EVAP canister
4. CO adjusting resistor (if equipped) d : Fuel pump relay D : DLC
5. CKP sensor e : IAC valve E : ABS control module (if equipped)
6. MAP sensor f : EVAP canister purge valve
7. CMP sensor g : EGR valve (if equipped)
8. Transmission range switch h : Fuel injector
9. VSS i : Ignition coil assemblies
10. HO2S-1 (if equipped) j : MIL
11. HO2S-2 (if equipped)
12. ECT sensor
13. Knock sensor
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DTC P0171 Fuel System Too Lean
DTC P0172 Fuel System Too Rich
CIRCUIT DESCRIPTION
[a] : Signal to decrease amount of fuel injection [d] : A/F mixture becomes richer
(Oxygen concentration decreases)1. Injector
[b] : Signal to increase amount of fuel injection [e] : High voltage 2. Heated oxygen sensor-1 (HO2S-1)
[c] : A/F mixture becomes leaner
(Oxygen concentration increases)[f] : Low voltage
DTC DETECTING CONDITION POSSIBLE CAUSE
When following condition occurs while engine running
under closed loop condition.
–Air / fuel ratio too lean
(Total fuel trim (short and long terms added) is more
than 30%)
or
–Air / fuel ratio too rich
(Total fuel trim is less than –30%)
✱
✱✱ ✱2 driving cycle detection logic, continuous monitoring.Vacuum leaks (air drawn in).
Exhaust gas leakage.
Heated oxygen sensor-1 circuit malfunction.
Fuel pressure out of specification.
Fuel injector malfunction (clogged or leakage).
MAP sensor poor performance.
ECT sensor poor performance.
IAT sensor poor performance.
TP sensor poor performance.
EVAP control system malfunction.
PCV valve malfunction.
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5 Check Fuel Injectors and Circuit.
1) Using sound scope (4) or such, check operating
sound of each injector (5) when engine is run-
ning. Cycle of operating sound should vary
according to engine speed. See Fig. 3.
If no sound or an unusual sound is heard, check
injector circuit (wire or coupler) or injector.
2) Turn ignition switch OFF and disconnect a fuel
injector connector.
3) Check for proper connection to fuel injector at
each terminal.
4) If OK, then check injector resistance.
See Fig. 4.
Injector resistance
11.3 – 13.8 ohm at 20 °C (68 °F)
5) Carry out steps 1) and 3) on each injector.
6) Check each injector for injected fuel volume
referring to Section 6E. See Fig. 5.
Injected fuel volume
43 – 47 cc/15 sec (1.45/1.51 – 1.58/1.65 US/
Imp.oz/15 sec)
7) Check each injector for fuel leakage after injec-
tor closed.
Fuel leakage
Less than 1 drop / min. (1)
Is check result in step 1) and 3) to 7) satisfactory?Go to Step 6. Check injector circuit or
replace fuel injector(s).
6 Check EVAP Canister Purge Valve.
1) Disconnect purge hose (2) from EVAP canister.
2) Place finger against the end of disconnected
hose.
3) Check that vacuum is not felt there when
engine is cool and running at idle. See Fig. 6.
Is vacuum felt?Check EVAP control
system (See Section
6E).Go to Step 7.
7 Check intake manifold absolute pressure sensor for
performance (See step 4) of DTC P0105 (No.11)
Diag. Flow Table).
Is it in good condition?Go to Step 8. Repair or replace.
8 Check engine coolant temp. sensor for perfor-
mance (See Section 6E).
Is it in good condition?Go to Step 9. Replace engine coolant
temp. sensor.
9 Check intake air temp. sensor for performance
(See Section 6E).
Is it in good condition?Go to Step 10. Replace intake air temp.
sensor.
10 Check throttle position sensor for performance
(See step 5) of DTC P0121 Diag. Flow Table).
Is it in good condition?Go to Step 11. Replace throttle position
sensor.
11 Check PCV valve for valve clogging
(See Section 6E).
Is it good condition?Substitute a known-
good ECM and recheck.Replace PCV valve. Step Action Yes No