ECM power supply SUZUKI SWIFT 2006 2.G Service Workshop Manual

Downloaded from www.Manualslib.com manuals search engine 1-ii Table of Contents
DTC P0123: Throttle / Pedal Position Sensor / Switch “A” (Main) Circuit High ....................... 1A-85
DTC P0131 / P0132: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-
1) ..................................................................... 1A-88
DTC P0133: O2 Sensor (HO2S) Circuit Slow
Response (Sensor- 1) ...................................... 1A-91
DTC P0134: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor -1) ........................... 1A-92
DTC P0137 / P0138: O2 Sensor (HO2S) Circuit Low Voltage / High Voltage (Sensor-
2) ..................................................................... 1A-94
DTC P0140: O2 Sensor (HO2S) Circuit No Activity Detected (Sensor -2) ........................... 1A-97
DTC P0171 / P0172: Fuel System Too Lean / Rich ................................................................. 1A-98
DTC P0222: Throttle / Pedal Position Sensor / Switch “B” (Sub) Circuit Low ....................... 1A-100
DTC P0223: Throttle / Pedal Position Sensor / Switch “B” (Sub) Circuit High ...................... 1A-102
DTC P0300 / P0301 / P0302 / P0303 / P0304: Random / Multiple Cylin der Misfire Detected
/ Cylinder 1 / Cylinder 2 / Cylinder 3 /
Cylinder 4 Misfire Detected ........................... 1A-105
DTC P0327 / P0328: Knoc k Sensor 1 Circuit
Low / High ..................................................... 1A-107
DTC P0335: Crankshaft Position (CKP) Sensor “A” Circuit .......................................... 1A-109
DTC P0340: Camshaft Position (CMP) Sensor “A” Circuit .......................................... 1A-111
DTC P0350: Ignition Coil Primary / Secondary Circuit ............................................................ 1A-114
DTC P0401 / P0402: Exhaust Gas Recirculation Flow Insufficient Detected /
Excessive Detected ...................................... 1A-116
DTC P0403: Exhaust Gas Recirculation Control Circuit ................... ............................ 1A-118
DTC P0420: Catalyst System Efficiency
below Threshold ................ ............................ 1A-120
DTC P0443: Evaporativ e Emission System
Purge Control Valve Circuit ........................... 1A-122
DTC P0480: Fan 1 (Radiator Cooling Fan) Control Circuit ................... ............................ 1A-124
DTC P0500: Vehicle Speed Sensor “A” Malfunction .................................................... 1A-128
DTC P0532: A/C Refrigerant Pressure Sensor “A” Circuit Low ... ............................... 1A-130
DTC P0533: A/C Refrigerant Pressure Sensor “A” Circuit High ................................. 1A-132
DTC P0601 / P0602 / P0607: Internal Control Module Memory Check Sum Error / Control
Module Programming Error / Control Module
Performance ................................................. 1A-134
DTC P0616: Starter Relay Circuit Low............ 1A-135
DTC P0617: Starter Relay Circuit High ........... 1A-136
DTC P0620: Generator Control Circuit ........... 1A-137
DTC P0625 / P0626: Generator Field Terminal Circuit Low / High . .......................... 1A-139
DTC P1501 / P1502: Electric Load Current Sensor Circuit Low / High . ............................ 1A-141 DTC P1510: ECM Back-Up Power Supply
Malfunction .................................................... 1A-143
DTC P1603: TCM Trouble Code Detected ..... 1A-144
DTC P1674: CAN Communication (Bus Off Error) ............................................................. 1A-145
DTC P1676: CAN Communication (Reception Error for TCM) ............................................... 1A-148
DTC P1678: CAN Communication (Reception Error for BCM) ............................................... 1A-149
DTC P1685: CAN Communication (Reception Error for ABS/ESP ® Control Module) ........... 1A-150
DTC P2101: Throttle Actuator Control Motor Circuit Range / Performance ......................... 1A-152
DTC P2102: Throttle Actuator Control Motor Circuit Low .................................................... 1A-154
DTC P2103: Throttle Actuator Control Motor Circuit High.................................................... 1A-155
DTC P2111 / P2112: Throttle Actuator Control System - Stuck Open / Closed ...................... 1A-156
DTC P2119: Throttle Actu ator Control Throttle
Body Range / Performance ........................... 1A-157
DTC P2122: Throttle / Pedal Position Sensor / Switch “D” (Main) Circuit Low Input............. 1A-159
DTC P2123: Throttle / Pedal Position Sensor / Switch “D” (Main) Circuit High Input ............ 1A-161
DTC P2127: Throttle Pedal Position Sensor / Switch “E” (Sub) Circuit Low Input ................ 1A-164
DTC P2128: Throttle / Pedal Position Sensor
/ Switc
h “E” (Sub) Circuit High Input ............. 1A-166
DTC P2135: Throttle / Pedal Position Sensor / Switch “A”/“B” (Main / Sub) Voltage
Correlation..................................................... 1A-168
DTC P2138: Throttle / Pedal Position Sensor / Switch “D”/“E” (Main / Sub) Voltage
Correlation..................................................... 1A-171
DTC P2227 / P2228 / P2229: Barometric Pressure Circuit Malfunction ......................... 1A-173
Inspection of ECM and Its Circuits .................. 1A-175
ECM Power and Ground Circuit Check........... 1A-194
Fuel Injector Circuit Check .............................. 1A-198
Fuel Pump and Its Circuit Check..................... 1A-200
Fuel Pressure Check....................................... 1A-203
A/C System Circuits Check ............................. 1A-205
Electric Load Signal Circuit Check .................. 1A-209
Radiator Cooling Fan Low Speed Control System Check ............................................... 1A-211
Radiator Cooling Fan High Speed Control System Check ............................................... 1A-213
Repair Instructions ......... .................................1A-216
Idle Speed and IAC Throttle Valve Opening Inspection ...................................................... 1A-216
Special Tools and Equipmen t .........................1A-217
Special Tool .................................................... 1A-217
Aux. Emission Control Devices ............. 1B-1
Diagnostic Information and Procedures ............1B-1
EGR System Inspection ...................................... 1B-1
Repair Instructions ............ ..................................1B-1
EVAP Canister Purge Inspec tion ........................ 1B-1

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Freeze frame data clearance:
The freeze frame data is cleared at the same time as
clearance of DTC.
Non-Euro-OBD
ECM diagnosis troubles which may occur in the area
including the following parts w hen the ignition switch is
ON and the engine is running, and indicates the result by
turning on or flashing malfunction indicator lamp (1).
• Heated oxygen sensor
• ECT sensor
•TP sensor
• APP sensor
• MAF sensor
• IAT sensor
• MAP sensor
• CMP sensor
• CKP sensor
• Knock sensor
• Wheel speed sensor (VSS)
• CPU (Central Processing Unit) of ECM
• Oil control valve
• EGR valve
• EVAP canister purge valve
• Ignition coil
• Starter relay
• Radiator fan relay
• CAN communication
• Barometric pressure sensor
• ECM back up power supply
ECM and malfunction indicator lamp (1) operate as
follows.
• Malfunction indicator lamp (1) lights when the ignition switch is turned ON (but t he engine at stop) with the
diagnosis switch terminal ungrounded regardless of
the condition of Engine and Emission control system.
This is only to check the ma lfunction indicator lamp (1)
in the combination meter and its circuit.
• If the above areas of Engine and Emission control system is free from any trouble after the engine start
(while engine is running), malfunction indicator lamp
(1) turns OFF. • When ECM detects a trouble which has occurred in
the above areas, it makes malfunction indicator lamp
(1) turn ON while the engi ne is running to warn the
driver of such occurrence of trouble and at the same
time it stores the trouble area in ECM back-up
memory. (The memory is kept as it is even if the
trouble was only temporary and disappeared
immediately. And it is not erased unless the power to
ECM is shut off for specified time or it is cleared by
SUZUKI scan tool (2).)
For Hong Kong model, DTC can be read by not only
using SUZUKI scan tool but also displayed on
odometer (5) of the combination meter. (i.e. when
diagnosis switch terminal (3) is grounded with a
service wire (4) and ignition switch is turned ON.) For
further detail of the checking procedure, refer to “DTC
Check”.
6. Diagnosis connector
2
1
6 3
5
4
I5RS0C110021-01

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Description of Electric Throttle Body System CalibrationS7RS0B1101008
ECM calculates controlled opening of the throttle valve on the basis of the completely closed throttle valve position of
the electric throttle body system. The completely closed position data is saved in memory of ECM. However, the
completely closed position of the throttle valve of the electric throttle body system (signal voltage from throttle position
sensor when throttle is completely closed) differs one from the other depending on individual differences of the throttle
valve and throttle position sensor. As such individual diff erences must be taken into account for controlling the throttle
valve, it is necessary to register the completely closed throttle valve position data in ECM. When such data is
registered in ECM, it is sa ved in RAM (memory) of ECM and used as the base data for controlling the throttle valve.
This data is cleared, when any of the works described in “Preca utions of Electric Throttle Body System Calibration” is
performed.
Also, after replacement of the throttle body and/or APP sensor , the completely closed position data in memory of ECM
must be cleared once and a new one must be registered, or ECM cannot judge the complete closure position properly.
For the procedure to register such data, refer to “Electric Throttle Body System Calibration in Section 1C”. (After the
completely closed position data is cleared , ECM, for the first time only, opens and closes the throttle valve for about 5
seconds after the ignition switch is turned ON position, for re gistration of the completely closed throttle valve position.
If the engine is started during this registration process, such symptom as “longe r cranking” or “slow rise of revolution
speed immediately after start-up” may occur. However, turning OFF the ignition switch once and restarting will set
correct registration.)
Fuel Cut Control DescriptionS7RS0B1101009
The fuel cut control in the vehicle stop is add ed as follows in order to prevent the over-rev.
Fuel Cut Control Table
4
1
2
17 3 5
6 7
8
9
10
11
12 13
14
15 16
18
I4RS0B110007-02
6. CPU 11. APP sensor (main) signal15. Drive signal of throttle actuator
7. Drive circuit of throttle actuator 12. APP sensor (sub) signal 16. Power supply of throttle actuator
9. From “TH MOT” fuse 13. TP sensor (main) signal 18. Control signal of throttle actuator control relay
10. From main relay 14. TP sensor (sub) signal
Vehicle ConditionOperative Condition
Sto p • Engine r/min > 6,000
• Engine r/min > 4,000 for 180 seconds
Run • Engine r/min > 7,500 (M/T model), Engine r/min > 6,800 (A/T model)

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Connector: E23Terminal Wire color Circuit Terminal Wire color Circuit 1 BLK/RED Main power supply 31 BLK Ground for ECM
2WHT/RED Power source for ECM internal
memory 32 RED/YELPower supply of throttle
actuator drive circuit
3RED CAN communication line
(active high signal) for ABS/
ESP®
control module, BCM,
combination meter 33 — —
4BRN Engine revolution signal output
for P/S control module 34 REDOutput of 5 V power source for
APP sensor (sub)
5 PPL/WHT 12 V serial communication line
of DLC 35 BRNOutput of 5 V power source for
APP sensor (main)
6 — — 36 YEL APP sensor (sub) signal
7 — — 37 GRN APP sensor (main) signal
8— — 38— —
9— — 39— —
10——40—— 11——41——
12 BLU Diagnosis switch terminal
(Hong Kong model) 42 — —
13 YEL/RED Clock signal for immobilizer
coil antenna 43 — —
14——44——
15 GRN/WHT Fuel pump relay output 45 BLU/ORN Throttle actuator control relay
output
16 BLK/RED Main power supply 46 LT GRN Radiator cooling fan relay No.1
output
17 — — 47 GRY A/C compressor relay output
18 WHT CAN communication line
(active low signal) for ABS/
ESP®
control module BCM,
combination meter 48 GRN
Radiator cooling fan relay No.2
and No.3 output
19 BLU/WHT Electric load signal for heater
blower motor 49 — —
20 GRN/WHT Brake light switch signal 50 — Ground for shield wire of APP
sensor
21 — — 51 WHT Ground for APP sensor (sub)
22 — — 52 BLU Ground for APP sensor (main)
23——53——
24 — — 54 ORN Ground for sensors
25 PPL Vehicle speed signal output for
P/S control module 55 REDA/C refrigerant pressure
sensor signal
26 RED/BLU EPS signal 56 — —
27 — — 57 WHT/BLK A/C evaporator outlet air temp.
sensor signal (Manual A/C
model)
28 YEL/BLK Serial communication line for
immobilizer coil antenna 58 — —
29 BLK/WHT Ignition switch signal 59 — —
30 WHT Starting motor control relay
output 60 BRN/WHT Main power supply relay output

Downloaded from www.Manualslib.com manuals search engine 1A-26 Engine General Information and Diagnosis:
DTC CheckS7RS0B1104003
NOTE
• There are two types of OBD system depending on the vehicle specification.
For details, refer to “Precaution on On-
Board Diagnostic (OBD) System”.
• The MIL is turned on when the ECM and/or TCM detect malfunction(s). Each ECM and
TCM stores diagnostic information as the
diagnostic trouble code (DTC) in its
memory and outputs th e DTC to the scan
tool.
Therefore, check both of the ECM and TCM
for any DTC with the SUZUKI scan tool
because the DTC stored in ECM and TCM
is not read and displayed at a time.
However, each of the ECM and TCM needs
not to be checked with the generic scan
tool because the DTC stored in ECM and
TCM is read and displayed at a time.

Using Scan Tool
1) Prepare OBD generic scan tool or SUZUKI scan tool.
2) With ignition switch turned OFF, connect it to DLC (1) located on underside of instrument panel at
driver’s seat side.
Special tool
(A): SUZUKI scan tool
3) Turn ignition switch ON and confirm that MIL lights.
4) Read DTC, pending DTC and freeze frame data according to instructions displayed on scan tool and
print them or write them down. Refer to scan tool
operator’s manual for further details.
If communication between scan tool and ECM is not
possible, check if scan tool is communicable by
connecting it to ECM in another vehicle. If
communication is possible in this case, scan tool is
in good condition. Then check data link connector
and serial data line (circuit) in the vehicle with which
communication was not possible. If connector and
circuit are OK, check that power supply and ground
circuits of ECM and DLC are in good condition
referring to “ECM Power and Ground Circuit Check”. 5) After completing the check,
turn ignition switch OFF
and disconnect scan tool from data link connector.
Without Using Scan Tool (Hong Kong Model) 1) Turn ignition switch to OFF position.
2) Using service wire, ground diagnosis switch terminal (1) of diagnosis connector (2).
3) Turn ON ignition switch and check DTC displayed on
odometer (3) of combination meter.
When more than 2 DTCs are stored in memory,
blinking for each DTC star ts with the smallest DTC
number in increasing order. Also, DTC is indicated
repeatedly until the ignition switch is turned OFF or
disconnect service wire.
NOTE
When no DTC is detected, display on
odometer of combinatio n meter is “0000”.

4) After completing the check, turn ignition switch to
OFF position and disconnect service wire from
diagnosis connector.
(A)
1
I4RS0B110026-01
21
3
I5RS0C110009-01

Downloaded from www.Manualslib.com manuals search engine 1A-30 Engine General Information and Diagnosis:
)
U *P0617 Starter relay circuit high Starter signal is high voltage for specified time while
engine is running. 2 driving
cycles
) P0620 Generator control circuit Battery voltage is higher than specification even through
generator control is maximum regulation, or battery
voltage is lower than specification even through generator
control is minimum regulation
and electric load is less
than 15 A. —
) P0625 Generator field/F terminal
circuit low Generator field coil duty is
0% (high voltage) for more
than specified time even through generator control is
minimum regulation. —
) P0626 Generator field/F terminal
circuit high Generator field coil duty is
100% (low voltage) for more
than specified time even through generator control is
maximum regulation, or generator field coil duty is 100%
(low voltage) when engine is starting. —
) P1501 Electric load current sensor
circuit low Electric load current is lowe
r than specified value (electric
load current sensor voltage is higher than specified
value). —
) P1502 Electric load current sensor
circuit high Electric load current is higher than specified value
(electric load current sens
or voltage is lower than
specified value). —
)
U *P1510 ECM backup power supply
malfunction Backup power voltage is out of
specification after starting
engine. 1 driving
cycle
) † P1603 TCM trouble code detected When ECM receives a trouble code from TCM, which
indicates that some problem occurred in sensor circuits
and its calculated values used for operations such as idle
speed control, engine power control and so on by TCM,
this DTC is detected by ECM. —
) *P1674 CAN communication (buss off
error) Transmission error that
is inconsistent between
transmission data and transmission monitor (CAN bus
monitor) data is detected more than 7 times continuously. 1 driving
cycle
)
† *P1676 CAN communication (reception
error for TCM) Reception error of communication data for TCM is
detected for longer than specified time continuously. 1 driving
cycle
) P1678 CAN communication (reception
error for BCM) Reception error of communication data for BCM is
detected for longer than specified time continuously.
—
) *P1685 CAN communication (reception
error for ABS/ESP
® control
module) Reception error of communication data for ABS/ESP
®
co

ntrol module is detected for longer than specified time
continuously. 1 driving
cycle
) *P2101 Throttle actuator control motor
circuit range/performance Monitor signal of throttle actuator output (duty output) is
inconsistent with throttle actuator control command. 1 driving
cycle
) *P2102 Throttle actuator control motor
circuit low Power supply voltage of throttle actuator control circuit is
lower than specification even
if throttle actuator control
relay turned on. 1 driving
cycle
) *P2103 Throttle actuator control motor
circuit high Power supply voltage of throttle actuator control circuit is
higher than specification even if throttle actuator control
relay turned off. 1 driving
cycle
) *P2111 Throttle actuator control
system – stuck open Throttle valve default opening is greater than specified
value from complementary closed position when
diagnosing throttle valve at ignition switch turned OFF. 1 driving
cycle
) *P2112 Throttle actuator control
system – stuck closed Throttle valve default opening is smaller than specified
value from complementary closed position when
diagnosing throttle valve at ignition switch turned OFF. 1 driving
cycle
) *P2119 Throttle actuator control throttle
body range/performance Difference between actual throttle valve opening angle
and opening angle calculated by ECM is more than
specification. 1 driving
cycle
) *P2122 Throttle/pedal position sensor/
switch “D” (main) circuit low
input Output voltage of APP sensor (main) is lower than
specification.
1 driving
cycle
DTC No. Detecting item
Detecting condition
(DTC will set when detecting:) MIL

Downloaded from www.Manualslib.com manuals search engine 1A-48 Engine General Information and Diagnosis:
Troubleshooting
NOTE
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special
tool to ECM and/or the ECM connectors referri ng to “Inspection of ECM and Its Circuits”.

Malfunction Indicator Lamp Remains ON after Engine StartsS7RS0B1104012
Wiring Diagram and Circuit Description
Refer to “MIL Does Not Come ON wit h Ignition Switch ON and Engine Stop (but Engine Can Be Started)”.
Step
Action YesNo
1 MIL power supply check
1) Turn ignition switch to ON position.
Do other warning lights come ON? Go to Step 2.
Go to Step 3.
2 DTC check
1) Connect scan tool to DLC with ignition switch turned
OFF.
2) Turn ON ignition switch and check DTC.
Is there DTC(s) P1674, P1676, P1678 and/or P1685? Go to applicable DTC
diag. flow.
Substitute a known-
good combination meter
and recheck. If MIL still
remains OFF, substitute
a known-good ECM and
recheck.
3 CAN communication line circuit check
1) Check CAN communication circuit between combination
meter and ECM, TCM (A/T model) referring to Step 3 of
“DTC P1674: CAN Communication (Bus Off Error)”
Is circuit in good condition? Go to Step 4.
Repair or replace.
4 “METER” fuse check
1) Turn ignition switch to OFF position.
2) Check for fuse blown at “M ETER” fuse in junction block
assembly.
Is “METER” fuse in good condition? Go to Step 5.
Replace “METER” fuse
and check for short.
5 Combination meter power supply check
1) Remove combination meter referring to “Combination
Meter Removal and Installation in Section 9C”.
2) Check for proper connection to combination meter connector at “G28-31” and “G28-16” terminals.
3) If OK, then turn ignition switch to ON position and measure voltage between combination meter connector
at “G28-31” terminal and vehicle body ground.
Is it 10 – 14 V? Go to Step 6.
“RED/BLK” wire is open
circuit.
6 Combination meter circuit check
1) Turn ignition switch to OFF position.
2) Measure resistance between “G28-16” terminal of
combination meter connector and vehicle body ground.
Is resistance 1
Ω or less? Substitute a known-
good combination meter
and recheck. If MIL still
remains OFF, substitute
a known-good ECM and
recheck.
“BLK/ORN” wire is open
or high resistance
circuit.

Downloaded from www.Manualslib.com manuals search engine 1A-50 Engine General Information and Diagnosis:
Circuit Description
Actual valve timing fails to become close to target advance level of each function although advance control function or
retarded advance control function is at work.
DTC Detecting Condition and Trouble Area
DTC Confirmation Procedure 1) Clear DTC. Refer to “DTC Clearance”.
2) Start engine and keep it at idle for 10 seconds.
3) Check DTC. Refer to “DTC Check”.
DTC Troubleshooting
NOTE
• When measuring circuit voltage, resistance and/ or pulse signal at ECM connector, connect the
special tool to ECM and/or the ECM connectors re ferring to “Inspection of ECM and Its Circuits”.
• Upon completion of inspection and repair work, perform “DTC Confirmation Procedure” and confirm that the trouble has been corrected.

DTC detecting condition Trouble area
Monitor signal of oil control valve is different from
command signal. (Circuit open or short)
(1 driving cycle detection logic) • Oil control valve
• Oil control valve circuit
•ECM
Step
Action YesNo
1 Was “Engine and Emission Control System Check”
performed? Go to Step 2.
Go to “Engine and
Emission Control
System Check”.
2 Oil control valve electrical circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Check for proper connection at “C37-60” and “C37-59” terminals of ECM connector.
3) If OK, measure resistance between “C37-60” and “C37- 59” terminals of ECM connector.
Is resistance below 10
Ω? Go to Step 3. Go to Step 8.
3 Oil control valve electrical circuit check
Was resistance more than 6.5
Ω in Step 2? Go to Step 4. Go to Step 7.
4 Oil control valve electrical circuit for power short check
1) Turn ON ignition switch.
2) Measure voltage between “C37-60” terminal of ECM
connector and engine ground.
Is voltage below 1 V? Go to Step 5. “RED”, “YEL/RED”,
“YEL” or “YEL/GRN”
wire is shorted to power
supply circuit.
5 Oil control valve electrical circuit for ground short
check
1) Disconnect connector from oil control valve with ignition
switch turned OFF.
2) Measure resistance between “C37-60” terminal of ECM connector and engine ground.
Is resistance infinity? Go to Step 6. “YEL/RED” wire is
shorted to ground
circuit.

Downloaded from www.Manualslib.com manuals search engine 1A-60 Engine General Information and Diagnosis:
4MAF sensor output voltage check
1) Turn OFF ignition switch.
2) Remove ECM from its br acket with ECM connectors
connected.
3) Measure voltage between “C37-26” and “C37-27” terminals of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Poor “C37-26” and/or
“C37-27” terminal
connection.
If OK, substitute a
known-good ECM and
recheck.
Go to Step 5.
5 MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal (2) of MAF
and IAT sensor connector (1).
Is voltage 10 – 14 V? Go to Step 6. “BLK/RED” wire is open
circuit.
6 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 8.
Go to Step 7.
7 Ground circuit check
1) Measure resistance between “C37-27” terminal of ECM
connector and vehicle body ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit is
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
8 MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Turn ON ignition switch, measure voltage between “GRN/BLK” wire terminal of MAF and IAT sensor
connector and engine ground.
Is voltage 0 V? Go to Step 9. “GRN/BLK” wire is
shorted to other circuit.
9 MAF sensor signal circuit check
1) Turn OFF ignition switch, measure resistance between
“GRN/BLK” wire terminal of MAF and IAT sensor
connector and engine ground.
Is resistance infinity? Go to Step 10. “GRN/BLK” wire is
shorted to ground
circuit.
Step Action Yes No
I4RS0A110020-01

Downloaded from www.Manualslib.com manuals search engine 1A-62 Engine General Information and Diagnosis:
3MAF sensor power supply voltage check
1) Disconnect connector from MAF and IAT sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage between engine ground and “BLK/RED” wire terminal of MAF and
IAT sensor connector.
Is voltage 10 – 14 V? Go to Step 4. “BLK/RED” wire is open
circuit.
4 MAF sensor ground circuit check
1) Turn OFF ignition switch, measure resistance between
“GRY” wire terminal of MAF and IAT sensor connector
and engine ground.
Is resistance below 5
Ω? Go to Step 6.
Go to Step 5.
5 Ground circuit check
1) Remove ECM from its br acket with ECM connectors
connected.
2) Measure resistance between “C37-27” terminal of ECM connector and engine ground.
Is resistance below 5
Ω? “GRY” wire is open or
high resistance circuit.
ECM grounds “E23-31”,
“C37-58”, “C37-15” and/
or “C37-30” circuit is
open or high resistance.
If wires are OK,
substitute a known-
good ECM and recheck.
6 MAF sensor signal circuit check
1) Disconnect connectors from ECM with ignition switch
turned OFF.
2) Measure voltage between “GRN/BLK” wire terminal of MAF and IAT sensor connector and engine ground with
ignition switch turned ON.
Is voltage 0 V? Go to Step 7. “GRN/BLK” wire is
shorted to other circuit.
7 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and engine ground
with ignition swit ch turned OFF.
Is resistance infinity? Go to Step 8.
“GRN/BLK” wire is
shorted to ground
circuit.
8 MAF sensor signal circuit check
1) Measure resistance between “GRN/BLK” wire terminal
of MAF and IAT sensor connector and “C37-26” terminal
of ECM connector.
Is resistance below 3
Ω? Go to Step 9.
“GRN/BLK” wire is open
or high resistance
circuit.
9 MAF sensor output signal check
1) Connect connectors to MAF and IAT sensor and ECM
with ignition swit ch turned OFF.
2) Measure voltage between “C37-26” and “C37-27” terminals of ECM connector referring to “MAF and IAT
Sensor On-Vehicle Inspection in Section 1C”.
Is each value within specified range? Substitute a known-
good ECM and recheck.
Faulty MAF and IAT
sensor.
Step
Action YesNo