Page 456 of 687

Downloaded from www.Manualslib.com manuals search engine ENGINE GENERAL INFORMATION AND DIAGNOSIS 6-99
DTC P1450 Barometric Pressure Sensor Low / High Input
DTC P1451 Barometric Pressure Sensor Performance Problem
WIRING DIAGRAM / CIRCUIT DESCRIPTION
Barometric pressure sensor is installed in ECM.
DTC CONFIRMATION PROCEDURE
1) Turn ignition switch OFF.
2) Clear DTC with ignition switch ON.
3) Turn ignition switch ON for 2 sec., crank engine for 2 sec. and run it at idle for 1 min.
4) Check pending DTC in “ON BOARD TEST” or “PENDING DTC” mode and DTC in “DTC” mode.
INSPECTION
DTC P1450 :
Substitute a known-good ECM and recheck.
DTC P1451 :
DTC DETECTING CONDITION POSSIBLE CAUSE
DTC P1450 :
Barometric pressure sensor voltage is 4.7 V or higher, or
1.6 V or lowerECM (barometric pressure sensor) malfunc-
tion
DTC P1451 :
Vehicle stopped
Engine cranking
Difference between barometric pressure and intake mani-
fold absolute pressure is 26 kPa, 200 mmHg or more.
Difference between intake manifold absolute pressure at
engine start and pressure after engine start is less than 1.3
kPa, 10 mmHg.
✱
✱✱ ✱2 driving cycle detection logic, monitoring once / 1 driving.ECM (barometric pressure sensor) malfunc-
tion
NOTE:
Note that atmospheric pressure varies depending on weather conditions as well as altitude.
Take that into consideration when performing these check.
Step Action Yes No
1Was “Engine Diag. Flow Table” performed? Go to Step 2. Go to “Engine Diag. Flow
Table”.
2 1) Connect scan tool to DLC with ignition
switch OFF. See Fig.1.
2) Turn ignition switch ON and select “DATA
LIST” mode on scan tool.
3) Check manifold absolute pressure.
Is it barometric pressure (approx. 100 kPa, 760
mmHg) at sea level?Substitute a known-good
ECM and recheck.Go to Step 3.
Page 614 of 687
Downloaded from www.Manualslib.com manuals search engine ENGINE AND EMISSION CONTROL SYSTEM 6E-9
ECM INPUT / OUTPUT CIRCUIT DIAGRAM
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.
Page 616 of 687
Downloaded from www.Manualslib.com manuals search engine ENGINE AND EMISSION CONTROL SYSTEM 6E-11
For TYPE B (See NOTE)
NOTE:
See NOTE in “ECM INPUT / OUTPUT CIRCUIT DIAGRAM” for applicable model.
Page 618 of 687

Downloaded from www.Manualslib.com manuals search engine ENGINE AND EMISSION CONTROL SYSTEM 6E-13
ECM TERMINAL ARRANGEMENT TABLE
For TYPE A (See NOTE)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
E191 B Ground for ECM
E187 W Backup power source
2 B/R Ground for drive circuit
8R/GImmobilizer indicator lamp
(if equipped)
3 B/R Ground for drive circuitDuty output terminal (vehicle without
immobilizer indicator lamp)
4 Bl/G Canister purge valve 9––
5 Bl/OrPower steering pressure switch
(if equipped)10 Bl Main relay
6 G/Y IAC valve 11 Br Tachometer
7 P/B Heater of HO2S-1 (if equipped) 12 Y/B Data link connector (5 V)
8 W/B No.4 fuel injector 13 WHeated oxygen sensor-2
(if equipped)
9 R/W No.1 fuel injector 14 W/BIDiagnosis switch terminal
(vehicle without immobilizer indicator
lamp)
10 B/Bl Ground for sensor circuit 15 PTest switch terminal
(vehicle without immobilizer indicator
lamp)
11 W CMP sensor 16 G/W A/C SW signal (if equipped)
12––17 R/Y Lighting switch
13R
R/BlHeated oxygen sensor-1
(if equipped)
CO adjusting resistor (w/o HO2S)18 P/B A/C condenser fan relay (if equipped)
14 G/B ECT sensor 19 W/G Fuel pump relay
15 Lg/B IAT sensor 20 B/Bl Ground for sensor
16 Lg TP sensor 21 B/RThrottle opening signal output for A/T
(A/T)
17 Gr/BIEGR valve (stepper motor coil 3, if
equipped)22 Y/RFuel level gauge (vehicle with immo-
bilizer indicator lamp)
18 GrEGR valve (stepper motor coil 1, if
equipped)23––
19 Br/BIG coil assembly for No.2 and 3 spark
plugs24 Bl/Y Heater blower switch
20 Br/WIG coil assembly for No.1 and 4 spark
plugs
21 R/G No.2 fuel injector
E171––
22 Lg/R Power supply for sensor 2 R R-range signal (A/T)
23 G/R CKP sensor 3––
24––4––
25 W Knock sensor 5 B/Or Overdrive cut signal (A/T)
26 G MAP sensor 6 G/Y D-range idle-up signal (A/T)
27 W/R A/C evaporator temp. sensor 7 G/W Stop lamp switch
28 Gr/BEGR valve (stepper motor coil 4, if
equipped)8––
29 Gr/REGR valve (stepper motor coil 2, if
equipped)9 B/W Ignition switch
30––10––
31 W/G No.3 fuel injector 11 Y Vehicle speed sensor
12 G ABS signal (if equipped)
E181 P A/C compressor clutch (if equipped) 13B/Y (M/T)
B/R (A/T)Engine start signal
2 V/Y Malfunction indicator lamp 14––
3 P/G Data link connector (12 V) 15––
4 R/BI Heater of HO2S-2 (if equipped) 16 R/W Rear defogger switch (if equipped)
5 Bl/B Power source 17 G/RA/T failure signal (A/T) (vehicle with
immobilizer indicator lamp)
6 Bl/B Power source
NOTE:
See NOTE in “ECM INPUT / OUTPUT CIRCUIT DIAGRAM” for applicable model.
Page 619 of 687

Downloaded from www.Manualslib.com manuals search engine 6E-14 ENGINE AND EMISSION CONTROL SYSTEM
For TYPE B (See NOTE)
CONNEC-
TORTERMINAL WIRE COLOR CIRCUITCONNEC-
TORTERMINAL WIRE COLOR CIRCUIT
E191 B Ground for ECM
E187 W Backup power source
2 B/R Ground for drive circuit
8R/GImmobilizer indicator lamp
(if equipped)
3 B/R Ground for drive circuitDuty output terminal (vehicle without
immobilizer indicator lamp)
4 Bl/G Canister purge valve 9––
5 Bl/OrPower steering pressure switch
(if equipped)10 Bl Main relay
6 G/Y IAC valve 11 B/W Ignition switch
7 P/B Heater of HO2S-1 (if equipped) 12 R/W Rear defogger switch
8 W/B No.4 fuel injector 13––
9 R/W No.1 fuel injector 14 W/BIDiagnosis switch terminal
(vehicle without immobilizer indicator
lamp)
10 B/Bl Ground for sensor circuit 15 PTest switch terminal
(vehicle without immobilizer indicator
lamp)
11 W CMP sensor 16 G/W A/C SW signal (if equipped)
12––17 R/Y Lighting switch
13R
R/BlHeated oxygen sensor-1
(if equipped)
CO adjusting resistor (w/o HO2S)18 P/B A/C condenser fan relay (if equipped)
14 G/B ECT sensor 19 W/G Fuel pump relay
15 Lg/B IAT sensor 20B/Y (M/T)
B/R (A/T)Engine start signal
16 Lg TP sensor 21 G/W Stop lamp switch
17 Gr/BIEGR valve (stepper motor coil 3, if
equipped)22 Y Vehicle speed sensor
18 GrEGR valve (stepper motor coil 1, if
equipped)23––
19 Br/BIG coil assembly for No.2 and 3 spark
plugs24––
20 Br/WIG coil assembly for No.1 and 4 spark
plugs
21 R/G No.2 fuel injector
E171 W/R A/C evaporator temp. sensor
22 Lg/R Power supply for sensor 2 R R-range signal (A/T)
23 G/R CKP sensor 3––
24––4––
25 W Knock sensor 5 B/Or Overdrive cut signal (A/T)
26 G MAP sensor 6 G/Y D-range idle-up signal (A/T)
27––7 Y/B Data link connector
28 Gr/BEGR valve (stepper motor coil 4, if
equipped)8––
29 Gr/REGR valve (stepper motor coil 2, if
equipped)9 V/Y Malfunction indicator lamp
30––10––
31 W/G No.3 fuel injector 11 P/G Data link connector (12 V)
12 G ABS signal (if equipped)
E181 P A/C compressor clutch (if equipped) 13 Bl/Y Heater blower switch
2––14 B/Bl Ground for sensor
3––15 B/R Throttle opening sensor
4 R/BI Heater of HO2S-2 (if equipped) 16 Br Tachometer
5 Bl/B Power source 17––
6 Bl/B Power source
NOTE:
See NOTE in “ECM INPUT / OUTPUT CIRCUIT DIAGRAM” for applicable model.
Page 652 of 687

Downloaded from www.Manualslib.com manuals search engine IGNITION SYSTEM (ELECTRONIC IGNITION SYSTEM 6F-3
SYSTEM WIRING DIAGRAM
Diagnosis
1. Ignition switch 7. No.1 spark plug
2. Main relay 8. No.2 spark plug
3. Ignition coil assembly for No.1 and No.4 spark plugs 9. No.3 spark plug
4. Ignition coil assembly for No.2 and No.3 spark plugs 10. No.4 spark plug
5. CMP sensor 11. Sensed information (MAP sensor, ECT sensor, IAT sensor, TP sensor, Knock sensor, VSS, Park/
Neutral position signal, Electric load signal, Engine start signal, Test switch terminal)
6. CKP sensor
Condition Possible Cause Correction
Engine cranks, but will
not start or hard to
start (No spark)Blown fuse for ignition coil Replace.
Loose connection or disconnection of lead wire
or high-tension cord(s)Connect securely.
Faulty high-tension cord(s) Replace.
Faulty spark plug(s) Adjust, clean or replace.
Faulty ignition coil Replace ignition coil assembly.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty ECM Replace.
Poor fuel economy or
engine performanceIncorrect ignition timing Check related sensors and CKP
sensor plate.
Faulty spark plug(s) or high-tension cord(s) Adjust, clean or replace.
Faulty ignition coil assembly Replace.
Faulty CKP sensor or CKP sensor plate Clean, tighten or replace.
Faulty ECM Replace.