6-1-28 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
TP SENSOR VOLT (TP Sensor Output Voltage, V)
Throttle Position Sensor reading provides throttle valve opening information in the from of voltage.
O2S B1 S1 (HO2S Bank 1 Sensor 1 Output Voltage, V) / O2S B2 S1 (HO2S Bank 2 Sensor 1 Output
Voltage, V)
It indicates output voltage of HO2S SENSOR 1 installed on exhaust manifold (pre-catalyst).
O2S B1 S2 (HO2S Bank 1 Sensor 2 Output Voltage, V) / O2S B2 S2 (HO2S Bank 2 Sensor 2 Output
Voltage, V)
If indicates output voltage of HO2S SENSOR 2 installed on exhaust pipe (post-catalyst). It is used to detect cat-
alyst deterioration.
FUEL SYSTEM B1 (Fuel System Bank 1 Status) / Fuel System B2 (Fuel System Bank 2 Status)
Air/fuel ratio feedback loop status displayed as one of the followings.
OPEN : Open loop-has not yet satisfied conditions to go closed loop.
CLOSED : Closed loop-using oxygen sensor(s) as feedback for fuel control.
OPEN-DRIVE COND : Open loop due to driving conditions (Power enrichment, etc.).
OPEN SYS FAULT : Open loop due to detected system fault.
CLOSED-ONE O2S : Closed loop, but fault with at least one oxygen sensor may be using single oxygen sensor
for fuel control.
CALC LOAD (Calculated Load Value, %)
Engine load displayed as a percentage of maximum possible load. Value is calculated mathematically using the
formula : actual (current) intake air volume ÷ maximum possible intake air volume x 100%.
TOTAL FUEL TRIM (%)
The value of total fuel trim is obtained by putting values of short term fuel trim and long term fuel trim together.
This value indicates how much correction is necessary to keep the air/fuel mixture stoichiometrical.
CANIST PRG DUTY (EVAP Canister Purge Flow Duty, %)
This parameter indicates valve ON (valve open) time rate within a certain set cycle of EVAP canister purge valve
which controls the amount of EVAP purge.
VEHICLE SPEED (km/h, MPH)
It is computed based on pulse signals from vehicle speed sensor on transfer or transmission.
FUEL CUT (ON/OFF)
ON : Fuel being cut (output signal to injector is stopped).
OFF : Fuel not being cut.
MAP (Manifold Absolute Pressure, mmHg, kPa)
This parameter indicates the pressure in the intake manifold absolute pressure.
A/C CONDENSER FAN (ON/OFF)
This parameter indicates the state of the A/C Condenser Fan control signal.
BLOWER FAN (ON/OFF)
This parameter indicates the state of the blower fan motor switch.
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-29
EGR VALVE (%)
This parameter indicates opening rate of EGR valve which controls the amount of EGR flow.
A/C SWITCH (ON/OFF)
ON : Command for operation being output from A/C amplifier to compressor.
OFF : Command for operation not being output.
PSP SWITCH (ON/OFF)
ON : PSP switch detects P/S operation. (high P/S pressure)
OFF : PSP switch not detects P/S operation.
PNP SIGNAL (Transmission Range Switch, P/N or D range)
Whether the transmission range switch (P/N position switch) at P or N range or at R, D, 2 or L range is displayed.
If at P or N range, “P/N range” is displayed and if at R, D, 2 or L range, “D range” is displayed.
FUEL TANK LEVEL (%)
This parameter indicates approximate fuel level in the fuel tank. As the detectable range of the fuel level sensor
is set as 0 to 100 %, however, with some models whose fuel tank capacity is smaller, the indicated fuel level may
be only 70 % even when the fuel tank is full.
ELECTRIC LOAD (ON/OFF)
ON : Small light switch ON or rear window defogger switch ON.
OFF : Small light switch OFF and rear window defogger switch OFF.
VSS (4-A/T) (km/h, MPH)
It is computed by using pulse signals from vehicle speed sensor on 4-speed automatic transmission.
THROT POS LEVEL (Throttle Position Level For 4-A/T, “0”, “1”, “2”, “3”, “4”,“5”,“6” or “7”)
This parameter indicates which level (zone) the throttle valve opening is in.
The throttle opening is divided into 8 levels (zones) from “0” (about idle position) to “7” (about full open) and sig-
nals are assigned to each opening level (zone). PCM controls the automatic gear change of the automatic trans-
mission by using these signals according to the signal from the TP sensor.
GEAR POSITION (1ST, 2ND, 3RD or 4TH)
The gear position is determined on the basis of the command state signals generated from PCM to shift sole-
noids A and B (#1 and #2) and displayed as shown in the table below.
SHIFT SOL #1 CON/MON (Shift Solenoid #1, A Command/monitor, ON/OFF)
CON-ON : ON command being output to shift solenoid #1, A.
CON-OFF : ON command not being output.
MON-ON : Electricity being passed to shift solenoid #1, A.
MON-OFF : Electricity not being passed.SHIFT SOLENOID-A SHIFT SOLENOID-B
DISPLAY1ST ON OFF
2ND ON ON
3RD OFF ON
4TH OFF OFF
6-1-36 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
Inspection of PCM (ECM) and its Circuits
PCM (ECM) and its circuits can be checked at PCM (ECM) wiring
couplers by measuring voltage and resistance.
VOLTAGE CHECK
1) Remove PCM (ECM) cover from bracket referring to PCM
(ECM) REMOVAL.
2) Check voltage at each terminal of couplers connected.CAUTION:
PCM/ECM cannot be checked by itself. It is strictly pro-
hibited to connect voltmeter or ohmmeter to PCM (ECM)
with couplers disconnected from it.
NOTE:
As each terminal voltage is affected by the battery volt-
age, confirm that it is 11 V or more when ignition switch
is ON.
1. PCM (ECM)
2. PCM (ECM) connector (Viewed from harness side)
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-37
TERMINAL CIRCUIT NORMAL VOLTAGE CONDITION
E61-1Power source for CO adjusting
resistor (if equipped)10 – 14 V Ignition switch ON
E61-2 Power source for back up 10 – 14 V Ignition switch ON and OFF
E61-3 – – –
E61-4Cruise control module
(throttle opening signal)
(if equipped)Ignition switch ON, Voltage varies as specified at figure in
cruise control diagnosis of Section 8E while throttle valve is
opened gradually.
E61-5Duty output terminal
(vehicle with monitor connector)0 – 1 V Ignition switch ON
E61-6 Tachometer 0 – 1 V Ignition switch ON, engine stops
E61-7Malfunction indicator lamp
(“SERVICE ENGINE SOON” lamp)0 – 2.5 V Ignition switch ON, engine stops
10 – 14 V Engine running
E61-8 A/C cut signal (if equipped)0 – 1.5 V A/C is not operating
10 – 14 V A/C is operating
E61-9 Main relay10 – 14 V Ignition switch OFF
0 – 2 VIgnition switch ON or for 4 seconds
after ignition switch OFF
E61-10 CO adjusting resistor (if equipped) – –
E61-11 – – –
E61-12Data link connector (5V)
(Vehicle with monitor connector)4 – 6 V Ignition switch ON
E61-13 Data link connector (12V) 10 – 14 V Scan tool not connected to DLC
E61-14Test switch terminal
(Vehicle with monitor connector)10 – 14 V Ignition switch ON
E61-15 Rear defogger switch (if equipped)0 – 1.5 VIgnition switch ON, rear defogger
switch OFF
10 – 14 VIgnition switch ON, rear defogger
switch
E61-16 Heater blower switch10 – 14 VIgnition switch ON, heater blower
switch OFF
0 – 1.5 VIgnition switch ON, heater blower
switch ON
E61-17 A/C signal (if equipped)10 – 14 VIgnition switch ON, A/C switch or
heater blower switch OFF
0 – 1 VIgnition switch ON, A/C switch ON
and heater blower switch ON
E61-18 – – –
E61-19 “4WD” lamp0 – 1 VIgnition switch ON, Transfer lever :
4H or 4L range
10 – 14 VIgnition switch ON, Transfer lever :
2H range
E61-20 “O/D OFF” lamp (A/T vehicle)0 – 1 VFor 4 sec. after ignition switch ON
or overdrive cut switch ON
10 – 14 VAfter 4 sec. from ignition switch ON
and overdrive cut switch OFF
E61-21 “POWER” lamp (A/T vehicle)0 – 1 VIgnition switch ON, P/N change
switch : POWER mode
10 – 14 VIgnition switch ON, P/N change
switch : NORMAL mode
6-1-42 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
RESISTANCE CHECK
1) Disconnect couplers (1) from ECM/PCM with ignition switch
OFF.
2) Check resistance between each pair of terminals of discon-
nected couplers (1) as listed in following table. CAUTION:
Never touch terminals of ECM/PCM itself or connect volt-
meter or ohmmeter (2).
CAUTION:
Be sure to connect ohmmeter (2) probe from wire har-
ness side of coupler.
Be sure to turn OFF ignition switch for this check.
Resistance in table represents that when parts temper-
ature is 20°C (68°F).
TERMINALS CIRCUIT STANDARD
RESISTANCECONDITION
E61-9 and E61-2 Main relay 79 – 95 Ω–
E61-22 and C51-3-20 A/C fan motor relay (if equipped) 75 – 110 ΩBattery disconnected
and ignition switch ON
E61-23 and C51-3-20 Fuel pump relay 79 – 95 Ω–
C51-3-6 and Body ground Ground Continuity –
C51-3-17 and Body ground Ground Continuity –
C51-1-1 and Body ground Shift solenoid B (A/T) 11 – 15 Ω–
C51-1-2 and Body ground Shift solenoid A (A/T)
C51-1-4 and C51-3-4 IAC valve (stepper motor coil 2) 25.5 – 33.5 Ω–
C51-1-5 and C51-3-4 IAC valve (stepper motor coil 1)
C51-1-8 and Body ground TCC solenoid (A/T) 11 – 15 Ω–
C51-1-15 and C51-3-4 EVAP canister purge valve 28 – 35 Ω–
C51-1-16 and C51-3-4 IAC valve (stepper motor coil 4) 25.5 – 33.5 Ω–
C51-1-17 and C51-3-4 IAC valve (stepper motor coil 3)
C51-2-1 and C51-3-4 Fuel injector No.2 13 – 16 Ω–
C51-2-2 and C51-3-4 Fuel injector No.1
C51-2-4, C51-2-5 and E61-9 Heater of HO2S-1 5.0 – 6.4 Ω–
C51-2-7 and Body ground Ground Continuity –
C51-2-8 and C51-3-4 Fuel injector No.4 13 – 16 Ω–
C51-2-9 and C51-3-4 Fuel injector No.3
C51-2-12 and C51-3-4 EGR valve (stepper motor coil 4) 20 – 24 Ω–
C51-2-13 and C51-3-4 EGR valve (stepper motor coil 3)
C51-2-14 and C51-3-4 EGR valve (stepper motor coil 2)
C51-2-15 and C51-3-4 EGR valve (stepper motor coil 1)
C51-2-16, C51- 2-17 and
E61-9Heater of HO2S-2 11.7 – 14.3 Ω–
C51-2-21 and C51-3-4 Fuel injector No.6
13 – 16 Ω–
C51-2-22 and C51-3-4 Fuel injector No.5
ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE) 6-1-43
Table A-1 Malfunction Indicator Lamp Circuit Check – Lamp Does Not Come
“ON” or Dims at Ignition Switch ON (But Engine at Stop)
WIRING DIAGRAM
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then,
ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine
starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected,
MIL remains ON even when the engine is running.
INSPECTION
1. MIL
2. To ignition switch
3. Main fuse
4. Main relay
5. ECM (PCM)
6. Monitor connector (if equipped)
Step Action Yes No
1 MIL power supply check :
1) Turn ignition switch ON.
Do other indicator/warning lights in combination
meter comes ON?Go to Step 2. “IG METER” fuse blown,
main fuse blown, Ignition
switch malfunction, “BLK/
WHT” circuit between “IG
METER” fuse and combi-
nation meter or poor cou-
pler connection at
combination meter.
6-1-52 ENGINE GENERAL INFORMATION AND DIAGNOSIS (H27 ENGINE)
DTC P0115 (DTC No.14, 15) Engine Coolant Temp. 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, pending DTC and freeze frame data by using scan tool and run
engine at idle speed for 10 sec. or more.
3) Check DTC by using scan tool.
1. ECT sensor
2. To combination (ECT) meter
3. ECM (PCM)
DTC DETECTING CONDITION TROUBLE AREA
Any one of the conditions are detected for 5 sec. continu-
ously.
• Low engine coolant temperature (high voltage-high
resistance)
• High engine coolant temperature (low voltage-low
resistance)ECT sensor circuit
ECT sensor
ECM (PCM)
NOTE:
Check to make sure that following conditions are satisfied when using this “DTC CONFIRMATION
PROCEDURE”.
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) 6-1-57
TROUBLESHOOTING
Fig. for Steps 4 and 5Step Action Yes No
1 Was “ENGINE DIAG. FLOW TABLE” performed? Go to Step 2. Go to “ENGINE
DIAG. FLOW TABLE”
in this section.
2 Is there a DTC related to TP sensor (DTC P0120)? Go to applicable DTC
Diag. Flow Table.Go to Step 3.
3 Do you have SUZUKI scan tool ? Go to Step 4. Go to Step 5.
4 Check TP sensor and its circuit (using SUZUKI
scan tool) :
1) Turn ignition switch OFF and connect SUZUKI
scan tool to DLC.
2) Turn ignition switch ON and check TP sensor
output voltage when throttle valve is at idle posi-
tion and fully opened.
Does voltage vary within specified value linearly as
shown in the figure?Substitute a known-good
ECM (PCM) and recheck.Go to Step 6.
5 Check TP sensor and its circuit (not using SUZUKI
scan tool) :
1) Turn ignition switch ON.
2) Check voltage at terminal C51-3-9 of ECM con-
nector connected, when throttle valve is at idle
position and fully opened.
Does voltage vary within specified value linearly as
shown in the figure?If voltmeter was used,
check terminal C51-3-9 for
poor connection.
If OK, substitute a known-
good ECM (PCM) and
recheck.Go to Step 6.
6 Check TP sensor :
1) Turn ignition switch OFF.
2) Disconnect TP sensor connector.
3) Check for proper connection to TP sensor at
each terminal.
4) If OK, check TP sensor for resistance referring
to “TP SENSOR” in Section 6E2.
Is check result satisfactory?High resistance in “GRY/
RED”, “RED/GRN” or
“GRY/YEL” circuit.
If wire and connection are
OK, substitute a known-
good ECM (PCM) and
recheck.Replace TP sensor.
1. Voltage
2. Throttle opening
3. At idle position
4. Fully open