Pressure sensor SUZUKI GRAND VITARA 2001 2.G Service Manual

ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-111
DTC P1408 Manifold Absolute Pressure Sensor Circuit Malfunction
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1. MAP sensor
2. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
•While engine is running after being warmed up and
with throttle opening smaller than specification,
higher than 4.6 V manifold absolute pressure sen-
sor output voltage is detected for specified time or
with throttle opening larger than specification, lower
than 0.2 V manifold absolute pressure output volt-
age is detected for specified time.
(2 driving cycle detection logic)•Manifold absolute pressure sensor
•Manifold absolute pressure sensor vacuum pas-
sage
•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.
NOTE:
Check to make sure that following condition is satisfied when using this “DTC CONFIRMATION PRO-
CEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)

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.

6-1-114 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P1500 Engine Starter Signal Circuit Malfunction
WIRING DIAGRAM
DTC DETECTING CONDITION AND TROUBLE AREA
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF.
2) Turn ON ignition switch and clear DTC by using scan tool, then start engine and run it for 3 min. or more.
3) Check pending DTC by using scan tool.
TROUBLESHOOTING
1. Engine start switch in ignition (main) switch 2. Starting motor 3. Transmission range sensor (switch) 4. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
•Engine starts even though vehicle is at stop and engine start signal is
not inputted.
or
•Engine start signal is inputted continuously for specified time while
engine is running.
(2 driving cycle detection logic)•Engine start signal circuit
•ECM (PCM)
NOTE:
Check to make sure that following condition is satisfied when using this “DTC CONFIRMATION PRO-
CEDURE”.
Intake air temp. : – 8°C (18°F) or higher
Engine coolant temp. : – 8 – 110°C (18 – 230°F)
Altitude (barometric pressure) : 2400 m, 8000 ft or less (560 mmHg (75 kPa) or more)
Step Action Yes No
1Was “ENGINE DIAG. FLOW TABLE” per-
formed?Go to Step 2. Go to “ENGINE DIAG. FLOW TABLE”
in this section.
2 Check for voltage at terminal C51-1-24 of
ECM (PCM) connector connected, under fol-
lowing condition.
Engine starter signal specification :
While engine cranking : 6 – 14 V
After starting engine : 0 – 1 V
Is voltage as specified?Poor C51-1-24 connection or
intermittent trouble.
Check for intermittent referring to
“INTERMITTENT AND POOR
CONNECTION” in Section 0A.
If wire and connections are OK,
substitute a known-good ECM
(PCM) and recheck.“BLK/YEL” circuit open.

ENGINE MECHANICAL (H27 ENGINE) 6A2-3
REMOVAL
1) Release fuel pressure in fuel feed line by referring to Section
6.
2) Disconnect negative (–) cable at battery.
3) Drain coolant.
4) Remove strut tower bar (2).
5) Disconnect coupler from intake air temp. sensor, and MAF
sensor.
6) Remove surge tank cover (1).
7) Remove air cleaner upper case, intake air hose, intake air
pipe (1) and surge tank pipe (2) as one component. Do not
disassemble them, when removing and reinstalling. CAUTION:
This work must not be done when engine is hot. If done
so, it may cause adverse effect to catalyst.
WARNING:
To help avoid danger of being burned, do not remove
drain plug and radiator cap while engine and radiator are
still hot. Scalding fluid and steam can be blown out under
pressure if plug and cap are taken off too soon.
1. Radiator
2. Radiator drain plug
2
1
1
2

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

6A2-6 ENGINE MECHANICAL (H27 ENGINE)
INSTALLATION
1) Install new intake manifold gaskets (1) to cylinder heads.
2) Install intake manifold (1).
Tighten bolts and nuts to specified torque.
Tightening torque
Intake manifold bolt and nut (a) :
23 N·m (2.3 kg-m, 16.5 lb-ft)
3) Install throttle body (2) to intake collector (1) with new throttle
body gasket.
Tighten bolts and nuts to specified torque.
Tightening torque
Throttle body bolt and nut (b) :
23 N·m (2.3 kg-m, 16.5 lb-ft)
4) Install EGR valve (1), EVAP canister purge valve (2), mani-
fold absolute pressure (MAP) sensor and each hoses to
intake collector and throttle body if removed.
Use new gasket, when installing IAC valve and EGR valve.
5) Install throttle body and intake collector assembly to intake
manifold with new intake collector gaskets.
1
(a)
(a)(a)
(a)
2 1
(b)
(b)
3. EVAP canister purge valve hose
2
1
3

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

6A2-26 ENGINE MECHANICAL (H27 ENGINE)
Unit Repair Overhaul
Engine Assembly
REMOVAL
1) Release fuel pressure in fuel feed line. Refer to “FUEL
PRESSURE RELIEF PROCEDURE” in Section 6.
2) Disconnect negative (–) cable at battery.
3) Remove engine hood.
4) Drain engine oil.
5) Drain coolant.
6) Remove radiator, radiator fan shroud, cooling fan and radia-
tor reservoir. Refer to “COOLING FAN AND FAN CLUTCH”
and “RADIATOR” in Section 6B.
7) Disconnect accelerator cable (1) and A/T throttle cable (for
A/T vehicle) (2) from throttle body.
8) Remove strut tower bar and surge tank cover.
9) Disconnect IAT sensor coupler and MAF sensor coupler then
remove air cleaner upper case, intake air hose, intake air
pipe and surge tank pipe as a component.
10) Remove engine oil level gauge guide and A/T fluid level
gauge guide (for A/T vehicle).
11) Remove ignition coil covers.
12

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

ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE) 6E2-1
6E2
SECTION 6E2
ENGINE AND EMISSION CONTROL SYSTEM
(SEQUENTIAL MULTIPORT FUEL INJECTION
FOR H27 ENGINE)
CONTENTS
General Description ..................................... 6E2-2
System Flow ............................................... 6E2-3
System Diagram ......................................... 6E2-4
Air Intake System ....................................... 6E2-6
Fuel Delivery System ................................. 6E2-7
Electronic Control System .......................... 6E2-8
Engine and Emission Control Input/Output
Table ........................................................ 6E2-12
Diagnosis .................................................... 6E2-12
On-Vehicle Service..................................... 6E2-13
General .................................................... 6E2-13
Accelerator Cable Adjustment .................. 6E2-14
A/T Throttle Cable Adjustment
(A/T Vehicle) ............................................ 6E2-14Idle Speed/Idle Air Control (IAC) Duty
Inspection................................................. 6E2-15
[Using SUZUKI scan tool] .................... 6E2-15
[Not using SUZUKI scan tool]
(vehicle with monitor connector) .......... 6E2-16
Idle mixture inspection/adjustment
(vehicle without heated oxygen sensor) 6E2-17
Air Intake System ..................................... 6E2-18
Throttle body ........................................ 6E2-18
Idle air control valve (IAC valve) .......... 6E2-21
Fast idle air valve ................................. 6E2-22
Fuel Delivery System ............................... 6E2-23
Fuel pressure inspection ...................... 6E2-23
Fuel pump ............................................ 6E2-24
Fuel pressure regulator ........................ 6E2-25 WARNING:
For vehicles equipped with Supplemental Restraint (Air Bag) System:
Service on and around the air bag system components or wiring must be performed only by an
authorized SUZUKI dealer. Refer to “Air Bag System Components and Wiring Location View” under
“General Description” in air bag system section in order to confirm whether you are performing ser-
vice on or near the air bag system components or wiring. Please observe all WARNINGS and “Ser-
vice Precautions” under “On-Vehicle Service” in air bag system section before performing service
on or around the air bag system components or wiring. Failure to follow WARNINGS could result in
unintentional activation of the system or could render the system inoperative. Either of these two
conditions may result in severe injury.
Technical service work must be started at least 90 seconds after the ignition switch is turned to the
“LOCK” position and the negative cable is disconnected from the battery. Otherwise, the system
may be activated by reserve energy in the Sensing and Diagnostic Module (SDM).
NOTE:
Whether following systems (parts) are used in the particular vehicle or not depends on specifications.
Be sure to bear this in mind when performing service work.
Monitor connector
CKP sensor
MAP sensor
EGR valve
Heated oxygen sensor or CO adjusting resistor
Three way catalytic converter, Warm-up three way catalytic converter