2001 SUZUKI GRAND VITARA brake

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-113
DTC P1450/P1451 Barometric Pressure Sensor Circuit Malfunction/Perfor-
mance Problem
SYSTEM DESCRIPTION
Barometric pressure sensor is installed in ECM (PCM).
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
For DTC P1450
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC by using scan tool and run engine for 1 min.
3) Check DTC by using scan tool.
For DTC P1451
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC, pending DTC and freeze frame data by using scan tool and warm up
engine to normal operating temperature.
3) Increase engine speed to 3,000 r/min. in 3rd gear in case of M/T and “2” range in case of A/T.
4) Release accelerator pedal and with engine brake applied, keep vehicle coasting for 5 sec. or more (keep fuel
cut condition for 5 sec. or more). If fuel cut condition is not kept for 5 sec. or more, coast down a slope in
engine speed 1600 – 3000 r/min for 5 sec. or more.
5) Stop vehicle and run engine at idle.
6) Repeat steps 3) – 5) 2 times.
7) Check pending DTC by using scan tool.
TROUBLESHOOTING (DTC P1450/P1451)
DTC DETECTING CONDITION TROUBLE AREA
DTC P1450 :
Barometric pressure out of specification is detected.•Barometric pressure sensor in ECM
(PCM)
DTC P1451 :
While running under conditions described for “DTC CONFIRMATION
PROCEDURE”, barometric pressure value compared with intake
manifold vacuum value in fuel cut state is not as specified.
(2 driving cycle detection logic)•Manifold absolute pressure sensor
performance problem
•Barometric pressure sensor in ECM
(PCM)
WARNING:
When performing a road test, select a place where there is no traffic or possibility of a traffic acci-
dent and be very careful during testing to avoid occurrence of an accident.
Road test should be carried out with 2 persons, a driver and a tester, on a level road.
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE DIAG. FLOW
TABLE” in this section.
2 Is DTC P1451 set? Go to Step 3. Substitute a known-good
ECM (PCM) and recheck.
3 MAP sensor check :
1) Check MAP sensor and its circuit referring to
Steps 2 and 3 of “DTC P1408 Diag. Flow Table”.
Is check result satisfactory?Substitute a
known-good
ECM (PCM) and
recheck.MAP sensor or its circuit mal-
function.

6A2-4 ENGINE MECHANICAL (H27 ENGINE)
8) Disconnect accelerator cable (1) and A/T throttle cable (2)
(for A/T vehicle) from throttle body.
9) Disconnect water hoses (3) from throttle body.
10) Disconnect injector wire (1) coupler.
11) Disconnect brake booster hose (2) from intake manifold.
12) Disconnect couplers of TP sensor (1) and IAC valve (2).
13) Disconnect earth terminal (3) from intake collector.
14) Remove clamp bracket (4) from intake collector.
15) Disconnect couplers from manifold absolute pressure (MAP)
sensor, EVAP canister purge valve, earth terminal and EGR
valve.
16) Disconnect PCV hose from cylinder head cover.
Disconnect breather hoses from throttle body or cylinder
head cover.
17) Disconnect hoses of EVAP canister purge valve and heater.
18) Remove EGR pipe.
12
33
2
1
2
14
3
1. EVAP canister purge valve 6. PCV hose
2. EGR valve 7. Water hose
3. EGR pipe 8. Breather hose
4. EVAP canister purge valve hose 9. Earth terminal coupler
5. Heater hose
9
4
1 7
6
2
35
8

ENGINE MECHANICAL (H27 ENGINE) 6A2-7
6) Connect hoses of heater, EVAP canister, fuel feed and fuel
return.
7) Install EGR pipe with new gaskets.
8) Connect hoses of EVAP canister purge valve and heater.
9) Connect hoses of PCV, breather and water.
10) Connect couplers of manifold absolute pressure (MAP) sen-
sor, EVAP canister purge valve and EGR valve.
Fix wire harness with clamps.
11) Install clamp bracket (4) to intake collector.
12) Connect earth terminal (3) to intake collector.
13) Connect couplers of TP sensor (1) and IAC valve (2).
14) Connect brake booster hose (2) to intake manifold.
15) Connect injector wire (1) coupler.
1. Heater hose
2. Fuel feed hose
3. Fuel return hose
4. EVAP canister hose
13
2 4
1. EVAP canister purge valve 6. PCV hose
2. EGR valve 7. Water hose
3. EGR pipe 8. Breather hose
4. EVAP canister purge valve hose 9. Earth terminal coupler
5. Heater hose9
4
1 7
6
2
35
8
2
14
3
2
1

ENGINE MECHANICAL (H27 ENGINE) 6A2-27
12) Disconnect the following electric lead wires :
•Injector wire coupler
•CMP sensor coupler
•Ignition coil couplers
•CKP sensor coupler
•MAP sensor coupler
•TP sensor (1) coupler
•IAC valve (2) coupler
•Earth wire (3) from surge tank
•EVAP canister purge valve coupler
•EGR valve coupler
•Oxygen sensor -1 and -2 couplers referring to “Exhaust Man-
ifold” in this section
•Coolant temperature sensor coupler
•Knock sensor coupler
•Generator wires
•Starter wires
•Oil pressure wire
•P/S pump wire
•Earth wire from generator bracket
•Engine block heater (if equipped)
13) Remove clamps and brackets.
14) Disconnect the following hoses :
•Heater hose from heater water pipe
•Heater hose from water outlet cap
•EVAP canister hose from canister pipe
•Brake booster vacuum hose
15) Remove EVAP canister purge valve (5).
16) Disconnect the following hoses at the location shown in the
figure :
•Fuel feed hose (1) from fuel feed pipe
•Fuel return hose from (2) fuel return pipe
17) Remove P/S pump assembly. Refer to “POWER STEERING
PUMP” in Section 3B1.
18) Remove A/C compressor assembly. Refer to “COMPRES-
SOR ASSEMBLY” in Section 1B.
19) Remove steering shaft lower assembly. Refer to “STEERING
LOWER SHAFT ASSEMBLY” in Section 3C1.
20) Raise vehicle.
21) Remove front differential housing with differential from chas-
sis if equipped. Refer to “DISMOUNTING” in Section 7E.
22) Remove exhaust No.1 pipe. Refer to “EXHAUST MANI-
FOLD” in this section.
23) Remove exhaust manifold stiffener from transmission.
4. Clamp bracket
6. EGR valve
7. Heater hose
2
14
3
75
6

6E2-6 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Air Intake System
The main components of the air intake system are air cleaner, mass air flow sensor, air cleaner, intake air pipe,
throttle body, intake collector, idle air control valve and intake manifold.
The air (by the amount corresponding to the throttle valve opening and engine speed) is filtered by the air
cleaner, passes through the throttle body, is distributed by the intake manifold and finally drawn into each com-
bustion chamber.
When the idle air control valve is opened according to the signal from ECM (PCM), the air bypasses the throttle
valve through bypass passage and is finally drawn into the intake manifold.
“A” : Air 1. Air cleaner 6. PCV hose 11. Breather hose 16. IAC valve and fast idle control system
“B” : EGR 2. IAT sensor 7. Brake booster 12. MAF sensor 17. FIA valve
“C” : Engine coolant 3. Resonator 8. Fuel pressure
regulator hose13. EGR valve 18. Thermo - WAX
4. Intake manifold 9. Intake air pipe 14. TP sensor
5. Intake collector 10. Throttle body 15. IAC valve
18
10
17
15
16

6E2-10 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
TERMINAL ARRANGEMENT OF ECM (PCM) CONNECTOR (VIEWED FROM HARNESS SIDE)
1. Fuel injector No.1 17.“O/D OFF” lamp (A/T) 34. Power steering pressure switch
2. Fuel injector No.2 18.“POWER” lamp (A/T) 35. Stop lamp switch (Brake pedal switch)
3. Fuel injector No.3 18-1.“4WD” lamp (4WD) 36. Lighting switch
4. Fuel injector No.4 18-2. 4WD air pump assembly (4WD) 37. Rear defogger switch (if equipped)
4-1. Fuel injector No.5 19. 4WD switch (4WD) 38. Heater blower motor (if equipped)
4-2. Fuel injector No.6 20. Power/Normal change switch (A/T) 39. A/C control module (amplifier)
5. EGR valve (if equipped) 21. O/D cut switch (A/T) 40. ABS control module
6. Idle air control 21-1. 4WD low switch (4WD) 41. Heated oxygen sensor-1 (Bank1) (if equipped)
7. EVAP canister purge valve 22. Main relay 41-1. Heated oxygen sensor-1 (Bank2) (if equipped)
8. Ignition coil for No.1 23. Transmission range switch (Park/Neutral
Position Switch) or clutch pedal position switch42. Heater oxygen sensor-2 (Bank1) (if equipped)
8-1. Ignition coil for No.2 24. Starter magnetic switch 42-1. Heater oxygen sensor-2 (Bank2) (if equipped)
9. Ignition coil for No.3 24-1. Cruise control module (if equipped) 43. Intake air temp. sensor
9-1. Ignition coil for No.4 25. Vehicle speed sensor 44. Engine coolant temp. sensor
10. Ignition coil for No.5 26. Combination meter 45. Throttle position sensor
10-1. Ignition coil for No.6 27. Data link connector 46. CO adjusting resistor (if equipped)
11. Fuel pump relay 28. TCC solenoid (A/T) 47. Manifold absolute pressure sensor (if
equipped)
12. Fuel pump 29. Shift solenoid-B (A/T) 48. Mass air flow sensor
13. A/C condenser fan relay (if equipped) 30. Shift solenoid-A (A/T) 49. Camshaft position sensor
14. A/C condenser fan motor (if equipped) 31. Transmission range switch (sensor) (A/T) 50. Crankshaft position sensor (if equipped)
15. Knock sensor 32. A/T input speed sensor (A/T) 51. Monitor connector (if equipped)
16. Malfunction indicator lamp 33. A/T vehicle (output) speed sensor (A/T) 52. Engine control module
(Powertrain control module)
TERMINAL CIRCUIT TERMINAL CIRCUIT TERMINAL CIRCUIT
E61-1 Power source for CO adjusting resistor
(if equipped)E61-13 Data link connector E61-25—
E61-2 Power source for back up E61-14 Test switch terminal (if equipped) E61-26—
E61-3—E61-15 Rear defogger switch (if equipped) E61-27—
E61-4 Cruise control module
(Throttle opening signal)E61-16 Heater blower switch E61-28—
E61-5 Duty output terminal (if equipped) E61-17 A/C signal (if equipped) E61-29 Diag. switch terminal (if equipped)
E61-6 Tachometer E61-18—E61-30 ABS control module (if equipped)
E61-7 MIL (“SERVICE INGINE SOON” lamp) E61-19“4WD” lamp E61-31 Power/Normal change switch (A/T)
E61-8 A/C cut signal (if equipped) E61-20“O/D OFF” lamp (A/T) E61-32 Lighting switch
E61-9 Main relay E61-21“POWER” lamp (A/T) E61-33 O/D cut switch (A/T)
E61-10 CO adjusting resistor (if equipped) E61-22 A/C fan motor relay (if equipped) E61-34 Stop lamp switch (Brake pedal switch)
E61-11—E61-23 Fuel pump relay E61-35 Cruise control module (if equipped)
E61-12—E61-24 Ground for CO adjusting resistor (if
equipped)

6E2-12 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Engine and Emission Control Input/Output Table
Diagnosis
Refer to Section 6-1.
Ignition coil with igniter
HO2S heater control
Input
Output Function
Main relay control
Fuel pump control
Injection control
Ignition control
MIL control Idle air control
EVAP purge control
EGR control
A/C control
A/C condensor fan
controlMain relay
Fuel pump relay
Injectors
MIL
EVAP canister purge
valve IAC valve
EGR valve (if equipped)
HO2S (if equipped)
A/C amplifier
(if equipped)
A/C condensor fan
relay (if equipped)
CMP sensor
MAF sensor
TP sensor
ECT sensor
IAT sensor
HO2S (sensor 1)(if equipped)
VSS
Blower fan switch
Rear defogger switch
PSP switch
Ignition switch
Starter switch
A/C amplifier (if equipped)
TR switch (A/T VEHICLE)
Light switch
Knock sensor
CO adjusting resistor (if equipped)
Test swich terminal (Vehicle with monitor connector)
Diag. swich terminal (Vehicle with monitor connector)
Brake switch (A/T VEHICLE)
ABS control module

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-13
On-Vehicle Service
General
When hoses are disconnected and system components are removed for service, reinstall components properly,
and route and connect hoses correctly after service. Refer to figure on previous page for proper routing of
hoses.
1. Brake booster hose pipe 8. EGR pipe (if equipped) 15. EVAP canister
2. Vacuum hose for fuel pressure regulator 9. Exhaust manifold 16. Tank pressure control valve
3. Fuel pressure regulator 10. Heated oxygen sensor 17. To fuel tank
4. MAP sensor (if equipped) 11. EGR valve (if equipped) 18. Cap
5. Engine coolant hose 12. PCV hose [A]: Vehicle without monitor connector
6. EVAP canister purge valve 13. IAC valve [B]: Vehicle with monitor connector
7. Breather hose 14. IAC hose