relay MAZDA 6 2002 Suplement Repair Manual

TROUBLESHOOTING
F2–191
F2
5 Inspect adjustment of accelerator position
sensor and idle switch.
(See F2–72 ACCELERATOR POSITION
SENSOR INSPECTION)
(See F2–70 IDLE SWITCH INSPECTION)
Are accelerator position sensor and idle switch
adjusted correctly?Yes Go to next step.
No Adjust accelerator position sensor and idle switch
correctly.
(See F2–73 ACCELERATOR POSITION SENSOR
ADJUSTMENT)
(See F2–71 IDLE SWITCH ADJUSTMENT)
6 Measure voltage PCM terminal 33 and 56.
Is voltage okay?Yes Go to next step.
NoPCM terminal 33 does not specified:
Inspect clutch switch and related harness.
PCM terminal 56 does not specified:
Inspect neutral switch and related harness.
7 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
8 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
9 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•RPM
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
10 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Replace common rail.
11 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Go to next step.
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION)
12 Is engine compression correct?
(See B2–8 COMPRESSION INSPECTION)Yes Go to next step.
No Inspect for following:
•Damaged valve seat
•Worn valve stem and valve guide
•Worn or stuck piston ring
•Worn piston, piston ring or cylinder
•Improper valve timing
Service as necessary.
13 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Go to next step.
No Repair or replace as necessary.
14Note
•The following test should be performed on
the vehicles with A/C system. If the
following test cannot be performed due to
engine stalling, go to next step.
•Go to next step for the vehicle without A/C
system.
Connect pressure gauge to A/C line.
Turn blower and A/C switches on.
Is pressure within specifications?Yes Go to next step.
NoA/C is always on:
Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
Other symptoms:
Inspect following:
•Refrigerant charging amount
•Cooling fan No.1 and/or cooling fan No.2 operation
15 Inspect EGR system operation.
Is EGR system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
16 Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Is glow system operation normal?Yes Go to next step.
No Service as necessary. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–193
F2
Diagnostic Procedure
STEP INSPECTION RESULTS ACTION
1 Is idle speed stable? Yes Go to next step.
No Go to symptom troubleshooting “NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE”.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING”.
No Go to next step.
3 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.
4 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging and/or restriction
•Intake-air system restriction or clogging
•Exhaust system and/or catalyst converter
restriction
•Cooling fan No.1 or cooling fan No.2 seat
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 4.
5 Does engine run normal after warm-up? Yes Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Replace any malfunctioning part as necessary.
If glow system is okay, go to next step.
No Go to next step.
6Note
•The following test should be performed on
the vehicles with A/C system. If the
following test cannot be performed due to
engine stalling, go to next step.
•Go to next step for the vehicle without A/C
system.
Connect pressure gauge to A/C line.
Turn blower and A/C switches on.
Is pressure within specifications?Yes Go to next step.
NoA/C is always on:
Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS CONTINUITY”.
Other symptoms:
Inspect following:
•Refrigerant charging amount
•Cooling fan No.1 and/or cooling fan No.2 operation
7 Inspect hose bands between following parts:
•Turbocharger compressor housing and air
cleaner
•Turbocharger compressor housing and
charge air cooler
Are hose bands loose?Yes Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
No Go to next step.
8 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
Is guide blade actuator okay?Yes Turbocharger is okay.
Go to next step.
No Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
9 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
10 Inspect idle speed.
(See F2–34 IDLE SPEED INSPECTION)
Is idle speed correct?Yes Go to next step.
No Repair or replace malfunctioning part according to idle
speed inspection results.

F2–196
TROUBLESHOOTING
3 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.
4 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging and/or restriction
•Intake-air system restriction
•Exhaust system and/or catalyst converter
restriction
•Charge air cooler condition (restriction or
damaged)
•Vacuum leakage
•Cooling fan No.1 and cooling fan No.2 seat
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 4.
5 Inspect intake shutter valve and VSC valve
operations.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
6 Inspect guide blade valve operation.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
7 Inspect A/C cut-off operation.
Does A/C cut-off work properly?Yes Go to next step.
No Repair or replace malfunctioning part according to A/C
cut-off system inspection results.
8 Inspect hose bands between following parts:
•Turbocharger compressor housing and air
cleaner
•Turbocharger compressor housing and
charge air cooler
Are hose bands loose?Yes Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
No Go to next step.
9 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is actuator okay?Yes Go to next step.
No Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
10 Remove parts necessary to inspect
turbocharger.
Do not remove turbocharger.
Inspect if turbocharger compressor wheel is
bent, damaged, or interfering with housing on
vehicle.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
11 Inspect if turbocharger compressor wheel
locknut is loose or has fallen down inside
turbocharger.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
12 Inspect if turbocharger compressor wheel by
hand.
Does wheel turn easily and smoothly?Yes Go to next step.
No Replace turbocharger. STEP INSPECTION RESULTS ACTION

F2–200
TROUBLESHOOTING
4 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.
5 Inspect intake shutter valve and VSC valve
operations.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
6 Inspect guide blade valve operation.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
7 Inspect hose bands between following parts:
•Turbocharger compressor housing and air
cleaner
•Turbocharger compressor housing and
charge air cooler
Are hose bands loose?Yes Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
No Go to next step.
8 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is actuator okay?Yes Go to next step.
No Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
9 Remove parts necessary to inspect
turbocharger.
Do not remove turbocharger.
Inspect if turbocharger compressor wheel is
bent, damaged, or interfering with housing on
vehicle.
(See F2–38 TURBOCHARGER INSPECTION)
Is there any problem?Yes Replace turbocharger.
No Go to next step.
10 Inspect if turbocharger compressor wheel
locknut is loose or has fallen down inside
turbocharger.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
11 Inspect turbocharger compressor wheel by
hand.
Does wheel turn easily and smoothly?Yes Go to next step.
No Replace turbocharger.
12 Inspect if turbocharger turbine wheel is
damaged, cracked or interfering with housing on
vehicle.
Note
•Inspect all fins on each turbine wheel.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
13 Is any engine oil found inside turbocharger
turbine housing?YesExcessive amount of oil is found:
Replace turbocharger.
Small amount of oil is found:
Wipe oil off of vehicle, then go to next step.
No Go to next step. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–201
F2
End Of Sie
14 Is any engine oil found inside turbocharger
compressor hosing?Yes Wipe oil off of vehicle and install all removed parts in
Step 10. Then, go to next step.
No Turbocharger is okay.
Install all parts removed in Step10.
Then, go to next step.
15 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
16 Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Is glow system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
glow system operation results.
17 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
18 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
19 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•MAP
•RPM
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
20 Is engine compression correct?
(See B2–8 COMPRESSION INSPECTION)Yes Go to next step.
No Inspect for following:
•Damaged valve seat
•Worn valve stem and valve guide
•Worn or stuck piston ring
•Worn piston, piston ring or cylinder
•Improper valve timing
Service as necessary.
21 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Inspect following:
•Boost sensor
•MAF/IAT sensor
•IAT sensor No.2
•Fuel pressure sensor
•Accelerator position sensor
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION)
22 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–203
F2
3 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.
4Note
•The following test should be performed on
the vehicles with A/C system. If the
following test cannot be performed due to
engine stalling, go to next step.
•Go to next step for the vehicle without A/C
system.
Connect pressure gauge to A/C line.
Turn blower and A/C switches on.
Is pressure within specifications?Yes Go to next step
NoA/C is always on:
Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
Other symptoms:
Inspect following:
•Refrigerant charging amount
•Cooling fan No.1 and/or cooling fan No.2
operation.
5 Access ECT PID.
Drive vehicle while monitoring PID.
Is PID within specification?Yes Go to next step.
No Inspect for coolant leakage, cooling fan No.1 and
cooling fan No.2 operations or thermostat operation.
6 Inspect idle speed.
(See F2–34 IDLE SPEED INSPECTION)
Is idle speed okay?Yes Go to next step.
No Go to symptom troubleshooting “NO.7 SLOW
RETURN TO IDLE”.
7 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
8 Inspect adjustment of accelerator position
sensor and idle switch.
(See F2–72 ACCELERATOR POSITION
SENSOR INSPECTION)
(See F2–70 IDLE SWITCH INSPECTION)
Are accelerator position sensor and idle switch
adjusted correctly?Yes Go to next step.
No Adjust accelerator position sensor and idle switch
correctly.
(See F2–73 ACCELERATOR POSITION SENSOR
ADJUSTMENT)
(See F2–71 IDLE SWITCH ADJUSTMENT)
9 Is engine compression correct?
(See B2–8 COMPRESSION INSPECTION)Yes Go to next step.
No Inspect for following:
•Damaged valve seat
•Worn valve stem and valve guide
•Worn or stuck piston ring
•Worn piston, piston ring or cylinder
•Improper valve timing
Service as necessary.
10 Inspect fuel injector.
(See F2–56 FUEL INJECTOR INSPECTION)
Is fuel injector okay?Yes Go to next step.
No Repair or replace as necessary.
11 Perform turbocharger inspection.
(See F2–38 TURBOCHARGER INSPECTION)
Is turbocharger okay?Yes Go to next step.
No Replace turbocharger.
12 Inspect guide blade valve operation.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
13 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts. STEP INSPECTION RESULTS ACTION

F2–206
TROUBLESHOOTING
3 Connect WDS or equivalent to DLC-2.
Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.
4 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel return line clogging and/or restriction
•Charge air cooler condition (restriction or
damaged)
•Intake-air system restriction
•Exhaust system and/or catalyst converter
restriction
•Vacuum leakage
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 4.
5 Inspect adjustment of accelerator position
sensor and idle switch.
(See F2–72 ACCELERATOR POSITION
SENSOR INSPECTION)
(See F2–70 IDLE SWITCH INSPECTION)
Are accelerator position sensor and idle switch
adjusted correctly?Yes Go to next step.
No Adjust accelerator position sensor and idle switch
correctly.
(See F2–73 ACCELERATOR POSITION SENSOR
ADJUSTMENT)
(See F2–71 IDLE SWITCH ADJUSTMENT)
6 Inspect adjustment of neutral switch.
(See F2–69 NEUTRAL SWITCH INSPECTION)
Is neutral switch adjusted correctly?Yes Go to next step.
No Adjust neutral switch correctly.
7 Inspect intake shutter valve and VSC valve
operations.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
8 Inspect guide blade valve operation.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is there any problem?Yes Repair or replace as necessary.
No Go to next step.
9 Inspect hose bands between following parts:
•Turbocharger compressor housing and air
cleaner
•Turbocharger compressor housing and
charge air cooler
Are hose bands loose?Yes Retighten hose bands.
If concern is resolved, complete inspection.
If concern still exists, go to next step.
No Go to next step.
10 Inspect for improper operation, kinks, clogging or
disconnection on guide blade actuator.
(See F2–229 ENGINE CONTROL SYSTEM
OPERATION INSPECTION)
Is actuator okay?Yes Go to next step.
No Repair or replace as necessary.
If concern is resolved, complete inspection.
If concern still exists, turbocharger is okay.
Go to next step.
11 Remove parts necessary to inspect
turbocharger.
Do not remove turbocharger.
Inspect if turbocharger compressor wheel is
bent, damaged, or interfering with housing on
vehicle.
(See F2–38 TURBOCHARGER INSPECTION)
Is there any problem?Yes Replace turbocharger.
No Go to next step. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–207
F2
12 Inspect if turbocharger compressor wheel
locknut is loose or has fallen down inside
turbocharger.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
13 Inspect turbocharger compressor wheel by
hand.
Does wheel turn easily and smoothly?Yes Go to next step.
No Replace turbocharger.
14 Inspect if turbocharger turbine wheel is
damaged, cracked or interfering with housing on
vehicle.
Note
•Inspect all fins on each turbine wheel.
Is there any problem?Yes Replace turbocharger.
No Go to next step.
15 Is any engine oil found inside turbocharger
turbine housing?YesExcessive amount of oil is found:
Replace turbocharger.
Small amount of oil is found:
Wipe oil off of vehicle, then go to next step.
No Go to next step.
16 Is any engine oil found inside turbocharger
compressor hosing?Yes Wipe oil off of vehicle and install all removed parts in
Step 10. Then, go to next step.
No Turbocharger is okay.
Install all parts removed in Step10.
Then, go to next step.
17 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
18 Inspect EGR water cooler for following:
•Coolant passage clogging/restriction
•Exhaust gas clogging/restriction
Is EGR water cooler okay?Yes Go to next step.
No Service as necessary.
19 Inspect glow system operation.
(See T–19 RELAY INSPECTION)
Is glow system operation normal?Yes Go to next step.
No Repair or replace malfunctioning part according to
glow system operation results.
20 Visually inspect CKP sensor and teeth of pulse
wheel.
Are CKP sensor and teeth of pulse wheel okay?Yes Go to next step.
No Replace malfunctioning parts.
21 Measure gap between CKP sensor and teeth of
pulse wheel.
Specification
1.5—2.5 mm {0.059—0.098 in}
Is gap within specification?Yes Go to next step.
No Adjust CKP sensor position.
22 Visually inspect CMP sensor and teeth of pulse
wheel.
Are CMP sensor and teeth of pulse wheel okay?Yes Inspect following PIDs:
(See F2–65 PCM INSPECTION)
•ECT
•IAT
•MAF
•MAP
•RPM
•VSS
If PID value is not as specified, repair or replace
malfunctioning parts.
If PID value is okay, go to next step.
No Replace malfunctioning parts.
23 Inspect fuel pressure sensor.
(See F2–79 FUEL PRESSURE SENSOR
INSPECTION)
Is fuel pressure okay?Yes Go to next step.
No Replace common rail.
24 Inspect suction control valve.
(See F2–54 SUCTION CONTROL VALVE
INSPECTION)
Is suction control valve okay?Yes Go to next step.
No Repair supply pump.
(See F2–54 SUPPLY PUMP INSPECTION) STEP INSPECTION RESULTS ACTION

F2–210
TROUBLESHOOTING
End Of SieNO.17 COOLING SYSTEM CONCERNS-OVERHEATINGA6E408018881219
Diagnostic Procedure
17
COOLING SYSTEM CONCERNS-OVERHEATING
DESCRIPTION•Engine runs at higher than normal temperature/overheats.
POSSIBLE
CAUSE•Cooling fan No.2 malfunction
•Cooling fan No.1 malfunction
•Low drive belt tension
•Drive belt damage
•Improper coolant level
•Thermostat malfunction
•Radiator clogging
•Improper water/anti-freeze mixture
•Improper or damaged radiator cap
•Radiator hose damage
•Coolant leakage (engine internal, turbocharger, external)
•A/C system malfunction
•EGR system malfunction
•Coolant heater system malfunction
STEP INSPECTION RESULTS ACTION
1 Inspect following:
•Engine coolant level
•Coolant leakage (around heater unit in
passenger compartment, coolant hoses and/
or radiator, and around coolant heater unit.)
•Water and anti-freeze mixture
•Radiator condition
•Collapsed or restricted radiator hoses
•Radiator pressure cap
•Drive belt tension
•Drive belt
•Fan rotational direction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 1.
2 Perform self-test function using WDS or
equivalent.
Turn engine switch to ON.
Retrieve any DTC.
Is DTC displayed?YesDTC is displayed:
Go to appropriate DTC test.
Communication error message is displayed:
Inspect for following:
•Open circuit between PCM control relay and PCM
terminal 53 or 79
•Open circuit PCM control relay and PCM terminal
69
•PCM control relay stuck open
•Open or poor GND circuit (PCM terminal 65, 85,
103 or 104)
•Poor connection vehicle body GND
NoNo DTC is displayed:
Go to next step.

TROUBLESHOOTING
F2–211
F2
End Of Sie
3Note
•The following test should be performed on
the vehicles with A/C system. Go to next
step for vehicles without A/C system
Start engine and run it at idle speed.
Turn A/C switch off.
Does A/C compressor disengaged?Yes Go to next step.
No Go to symptom troubleshooting “NO.24 A/C ALWAYS
ON OR A/C COMPRESSOR RUNS
CONTINUOUSLY”.
4 Start engine and run it at idle speed.
Turn A/C switch on if equipped.
Do cooling fan No.1 and/or cooling fan No.2
operate?Yes Go to next step.
NoCooling fan No.1 does not operate:
Inspect for following:
•Cooling fan relay No.1 is stuck open
•Cooling fan motor No.1 malfunction
•Cooling fan motor No.1 GND open
•Open circuit between cooling fan motor No.1 and
relay
•Open circuit between cooling fan relay No.1 and
PCM terminal 102
•Open battery power circuit of cooling fan relay
No.1
Cooling fan No.2 does not operate:
Inspect for following:
•Cooling fan relay No.2 is stuck open
•Cooling fan motor No.2 malfunction
•Cooling fan motor No.2 GND open
•Open circuit between Cooling fan motor No.2 and
relay
•Open circuit between Cooling fan relay No.2 and
PCM terminal 76
•Open battery power circuit of Cooling fan relay
No.2
5 Is drive belt okay? Yes Go to next step.
No Replace drive belt.
6 Perform EGR system inspection.
Is EGR system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
EGR system operation results.
7 Perform coolant heater system inspection.
(See E–10 THERMOSTAT INSPECTION)
Is coolant heater system okay?Yes Go to next step.
No Repair or replace malfunctioning part according to
coolant heater system operation results.
8 Cool down engine.
Remove thermostat and inspect operation.
Is thermostat okay?Yes Thermostat is okay.
Inspect cylinder block for leakage or blockage.
No Replace thermostat.
9 Verify test results.
•If okay, return to diagnostic index to service any additional symptoms.
•If malfunction remains, replace PCM. (See F2–64 PCM REMOVAL/INSTALLATION) STEP INSPECTION RESULTS ACTION