2001 SUZUKI GRAND VITARA Pressure sensor

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