1999 SUZUKI GRAND VITARA accelerator pedal

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.

6E2-14 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Accelerator Cable Adjustment
1) With throttle valve closed, check accelerator pedal play
which should be within following specification.
If measured value is out of specification, adjust accelerator
cable (1) to specification with cable adjusting nut (2).
Accelerator pedal play “a”:
2 – 5 mm (0.08 – 0.20 in.)
2) With accelerator pedal depressed fully, check clearance
between throttle lever (2) and lever stopper (1) (throttle body)
which should be within following specification.
If measured value is out of specification, adjust it to specifi-
cation by changing height of pedal stopper bolt (3).
Clearance “b” between throttle lever and lever stopper
(throttle body) (with accelerator pedal depressed fully):
0.5 – 2.0 mm (0.02 – 0.07 in.)
A/T Throttle Cable Adjustment (A/T Vehicle)
1) Make sure that accelerator cable is adjusted as specified.
2) With throttle valve closed, check clearance “c” which should
be within the following specification.
If it is out of specification, adjust A/T throttle cable (1) by
turning cable adjusting nut (2).
A/T throttle cable installing position specification clear-
ance “c”:
0.8 – 1.5 mm (0.03 – 0.06 in.)

6E2-44 ENGINE AND EMISSION CONTROL SYSTEM (SEQUENTIAL MULTIPORT FUEL INJECTION FOR H27 ENGINE)
Emission Control System
EGR system (if equipped)
EGR SYSTEM INSPECTION (USING SUZUKI SCAN TOOL)
1) Connect SUZUKI scan tool to data link connector (DLC) (1)
with ignition switch OFF.
Special tool
(A) : SUZUKI scan tool
2) Start engine and warm up it to normal operating tempera-
ture.
3) With engine idling (without depressing accelerator pedal),
open EGR valve by using “MISC. TEST” mode.
In this state, according as EGR valve opening increases
engine idle speed drops. If not, possible cause is clogged
EGR gas passage, stuck or faulty EGR valve.
REMOVAL
1) Disconnect negative (–) cable at battery.
2) Disconnect EGR valve coupler.
3) Remove wire harness bracket from intake collector.
4) Remove EGR valve (5) and gasket from intake collector.NOTE:
For operation procedure of cartridge, refer to its car-
tridge operator's manual.
1. SUZUKI scan tool display
2. EGR valve opening (0: Close, 100: Full Open)
1. EVAP canister purge valve 4. EGR pipe
2. EVAP canister purge valve hose 6. PCV hose
3. Breather hose

AUTOMATIC TRANSMISSION (4 A/T) 7B1-27
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF, if available.
2) Clear DTC, pending DTC and freeze frame data in PCM memory by using scan tool and start engine.
3) Shift A/T selector lever to each of L, 2, D, N, R and P ranges for 30 seconds each.
4) Increase vehicle speed to about 70 km/h (45 mile/h) in D range.
5) Keep driving above vehicle speed for 30 seconds.
6) Release accelerator pedal, decrease vehicle speed and stop vehicle.
7) Check DTC and/or pending DTC.
TROUBLESHOOTING
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 “A/T DIAGNOSTIC FLOW TABLE” in this section
performed?Go to Step 2. Go to “A/T DIAGNOS-
TIC FLOW TABLE” in
this section.
2 Do you have SUZUKI scan tool? Go to Step 3. Go to Step 4.
3 Check Transmission range switch (sensor) circuit for
operation.
Check by using SUZUKI scan tool :
1) Connect SUZUKI scan tool to DLC with ignition
switch OFF.
2) Turn ignition switch ON and check transmission
range signal (P, R, N, D, 2 or L) on display when
shifting select lever to each range.
Is applicable range indicated?
Are check results satisfactory?Intermittent trouble.
Check for intermittent
referring to “INTER-
MITTENT AND POOR
CONNECTION” in
Section 0A.Go to Step 5.
4 Check Transmission range switch (sensor) circuit for
operation.
Check by not using SUZUKI scan tool :
1) Turn ignition switch ON.
2) Check voltage at terminals C51-1-6, C51-1-7,
C51-1-18, C51-1-19, C51-1-27 and C51-1-28
respectively with select lever shifted to each
range.
Taking terminal C51-1-28 as an example, is battery
voltage indicated only when select lever is shifted to
“2” range and 0 V for other ranges as shown in figure?
Check voltage at other terminals likewise, referring to
figure.
Are check results satisfactory?Intermittent trouble.
Check for intermittent
referring to “INTER-
MITTENT AND POOR
CONNECTION” in
Section 0A.Go to Step 5.
5 Check select cable for adjustment referring to
“SELECT CABLE ADJUSTMENT” in this section.
Is it adjusted correctly?Go to Step 6. Adjust.

AUTOMATIC TRANSMISSION (4 A/T) 7B1-35
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF, if available.
2) Clear DTC, pending DTC and freeze frame data in PCM memory by using scan tool.
3) Start engine, warm it up to normal operating temperature and shift transfer lever to “2H” or “4H” range.
4) Shift selector lever in D range and keep it there for 10 seconds.
5) Increase vehicle speed to about 80 km/h (50 mile/h) in 4th gear and in D range.
6) Keep driving at above speed for 20 seconds.
7) Release accelerator pedal, decrease vehicle speed and stop vehicle.
8) Check DTC and/or pending DTC.
TROUBLESHOOTING
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 “A/T DIAGNOSTIC FLOW TABLE” in this
section performed?Go to Step 2. Go to “A/T DIAGNOSTIC
FLOW TABLE” in this sec-
tion.
2 Check TCC solenoid circuit for short.
1) Turn ignition switch OFF and disconnect
PCM connectors.
2) Check for proper connection to PCM at ter-
minal C51-1-8.
3) If OK, then turn ignition switch ON and mea-
sure voltage between terminal C51-1-8 of
disconnected PCM connector and ground.
Is it about 0 V?Go to Step 3.“GRN/YEL” circuit shorted
to power circuit.
3 Check TCC solenoid circuit for open or short.
1) Turn ignition switch OFF.
2) Measure resistance between terminal C51-
1-8 of disconnected PCM connector and
ground.
Is it 11 – 15 Ω (at 20 °C (68 °F))?Intermittent trouble or
faulty PCM.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.“GRN/YEL” circuit open or
shorted to ground.
If wire and connections
are OK, replace TCC
solenoid.

AUTOMATIC TRANSMISSION (4 A/T) 7B1-37
DTC CONFIRMATION PROCEDURE
1) Connect scan tool to DLC with ignition switch OFF, if available.
2) Clear DTC, pending DTC and freeze frame data in PCM memory by using scan tool.
3) Start engine and shift transfer lever to “2H” or “4H” range.
4) Shift selector lever in D range and keep it for 10 seconds.
5) Drive vehicle about 30 km/h (20 mile/h) with 2nd gear in “D” range for 10 seconds.
6) Increase vehicle speed to about 80 km/h (50 mile/h) with 4th gear in D range and keep it for 10 seconds.
7) Release accelerator pedal, decrease vehicle speed and stop vehicle.
8) Check DTC and/or pending DTC.
TROUBLESHOOTING
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 “A/T DIAGNOSTIC FLOW TABLE” in this
section performed?Go to Step 2. Go to “A/T DIAGNOSTIC
FLOW TABLE” in this sec-
tion.
2 Check shift solenoid circuit for short.
1) Turn ignition switch OFF and disconnect
PCM connectors.
2) Check for proper connection to PCM at ter-
minals C51-1-2 or C51-1-1.
3) If OK, then turn ignition switch ON and mea-
sure voltage between terminal C51-1-2 or
C51-1-1 of disconnected PCM connector
and ground.
Is it about 0 V?Go to Step 3.“GRN” or “GRN/RED“ cir-
cuit shorted to power cir-
cuit.
3 Check shift solenoid circuit for open or short.
1) Turn ignition switch OFF.
2) Measure resistance between terminal C51-
1-2 or C51-1-1 of disconnected PCM con-
nector and ground.
Is it 11 – 15 Ω (at 20 °C (68 °F))?Intermittent trouble or
faulty PCM.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.“GRN” or “GRN/RED“ cir-
cuit open or shorted to
ground.
If wire and connections
are OK, replace malfunc-
tion shift solenoid.

7B1-38 AUTOMATIC TRANSMISSION (4 A/T)
Stall Test
This test is to check overall performance of automatic transmission and engine by measuring stall speed at “D”
and “R” ranges. Be sure to perform this test only when transmission fluid is at normal operating temperature and
its level is between FULL and LOW marks.
1) Apply parking brake and block wheels.
2) Install tachometer.
3) Start engine with select lever shifted to “P”.
4) Depress brake pedal fully.
5) Shift select lever to “D” and depress accelerator pedal fully while watching tachometer. Read engine rpm
quickly when it has become constant (stall speed).
6) Release accelerator pedal immediately after stall speed is checked.
7) In the same way, check stall speed in “R” range.
8) Stall speed should be within the following specification.
Stall speed :
2,460 – 2,760 r/min.
TROUBLESHOOTING
CAUTION:
Do not run engine at stall more than 5 seconds continuously, for fluid temperature may rise exces-
sively high.
After performing stall test, be sure to leave engine running at idle for longer than 30 seconds before
another stall test.
Condition Possible cause
Lower than standard level•Faulty engine output
•Defective torque converter
Higher than standard level in “D” range•Slippery O/D clutch
•Slippery forward clutch
•Malfunctioning O/D one-way clutch
•Malfunctioning one-way clutch No. 2
•Low line pressure
Higher than standard level in “R” range•Slippery direct clutch
•Slippery reverse brake
•Low fluid pressure
•Slippery O/D clutch
•Defective O/D one-way clutch

7B1-40 AUTOMATIC TRANSMISSION (4 A/T)
TROUBLESHOOTING
Road Test
This test is to check if upshift and downshift take place at specified speed while actually driving vehicle on a
level road.
1) Warm up engine.
2) With engine running at idle, shift select lever “D”.
3) Accelerate vehicle speed by depressing accelerator pedal gradually.
4) While driving in “D” range, check if gear shift occurs properly as shown in “GEAR SHIFT DIAGRAM” in this
section.
TROUBLESHOOTING
Condition Possible cause
Line pressure higher than standard level in each
range•Malfunctioning regulator valve
•Malfunctioning throttle valve
•Maladjusted A/T throttle cable
Line pressure lower than standard level in each
range•Defective O/D clutch
•Defective oil pump
•Malfunctioning throttle valve
•Malfunctioning regulator value
•Maladjusted A/T throttle cable
Line pressure lower than standard level only in
“D” range•Fluid leakage from forward clutch
•Defective O/D clutch
•Leakage from “D” range fluid pressure circuit
Line pressure lower than standard level only in
“R” range•Fluid leakage from direct clutch
•Defective O/D clutch
•Fluid leakage from reverse brake
•Fluid leakage from “R” range fluid circuit
WARNING:
Carry out test in very little traffic area to prevent an accident.
Test requires 2 persons, a driver and a tester.
Condition Possible cause
When 1 → 2 upshift fails to occur 1–2 shift valve stuck
When 2 → 3 upshift fails to occur 2–3 shift valve stuck
When 3 → O/D upshift fails to occur 3–4 shift valve stuck
When gear shift point is incorrect•Maladjusted throttle cable
•Defective shift solenoid valve -A or -B
•1–2, 2–3 or 3–4 shift valve not operating properly