fuel filter MAZDA 6 2002 Suplement Owner's Manual

FUEL SYSTEM
F2–51
F2
FUEL FILTER COMPONENT DISASSEMBLY/ASSEMBLYA6E4012348022021. Disassemble in the order indicated in the table..
2. Assemble in the reverse order of removal.
Sedimentor Switch Installation Note
1. Apply a small amount of fuel to a new O-ring.
2. Tighten the sedimentor switch enough to the fuel
filter by hand.
Fuel Filter Installation Note
1. Apply a small amount of fuel to the fuel filter O-ring.
2. Tighten the fuel filter approx. 3/4 by hand after the O-ring contacts the priming pump.
End Of Sie
FUEL WARMER INSPECTIONA6E401234802203For Cold Areas
1. Remove the fuel warmer. (See F2–51 FUEL FILTER COMPONENT DISASSEMBLY/ASSEMBLY.)
2. Verify that the resistance between terminal A and
the fuel warmer body is within the specification
when vacuum of –31.3— –38.0 kPa {–235— –
285 mmHg, –9.2— –11.2 inHg} is applied to port
A of the fuel warmer.
•If as specified, carry out the “Circuit Open/
Short Inspection”.
•If not as specified, replace the fuel warmer.
Specification
Circuit Open/Short Inspection
1. Inspect for open/short circuit in the following
wiring harnesses.
•If there is open/short circuit, repair or replace
wiring harnesses.
Open circuit
•If there is no continuity, the circuit is open. Repair
or replace the harness.
—Fuel warmer terminal A (harness-side) and
GND
—Fuel warmer terminal B (harness-side) and
power supply
Short circuit
•If there is continuity, the circuit is shorted. Repair or replace the harness.
—Fuel warmer terminal B (harness-side) and GND
End Of Sie
1 Connector
2 Fuel hose
3 Priming pump
4Fuel filter
(See F2–51 Fuel Filter Installation Note)
5Sedimentor switch
(See F2–51 Sedimentor Switch Installation Note)
6 Drain plug
7 Fuel warmer
R
17.6—26.5
{1.8—2.7,
13.0—19.8}
7
5
4
3
6
1
2
N.m {kgf·m, ft·lbf}
A6E40122036
Ambient temperature (°C {°F}) Resistance (ohms)
20 {68} 0.5—1.5
FUEL WARMER
B
A6E40122013
A B FUEL WARMER
HARNESS SIDE CONNECTOR
A6E40122014

F2–52
FUEL SYSTEM
SEDIMENTOR WATER DRAININGA6E4012348022041. Disconnect the negative battery cable.
2. Complete the “BEFORE REPAIR PROCEDURE”. (See F2–45 BEFORE REPAIR PROCEDURE.)
3. Loosen the drain plug located at the bottom of the fuel filter.
4. Pump the priming pump and drain the water.
5. After all the water has been drained, tighten the drain plug.
6. Complete the “AFTER REPAIR PROCEDURE”. (See F2–45 AFTER REPAIR PROCEDURE.)
7. Reconnect the negative battery cable.
End Of Sie
SEDIMENTOR SWITCH INSPECTIONA6E401213840201
Note
•Perform the following test only when directed.
1. Disconnect the negative battery cable.
2. Complete the “BEFORE REPAIR PROCEDURE”. (See F2–45 BEFORE REPAIR PROCEDURE.)
3. Drain fuel from the fuel filter. (See F2–52 SEDIMENTOR WATER DRAINING.)
4. Remove the sedimentor switch.
5. Inspect for continuity of the sedimentor switch
using an ohmmeter.
•If as specified, inspect the following and carry
out the “Circuit Open/Short Inspection.”
•If not as specified, replace the sedimentor
switch.
Specification
6. Install the sedimentor switch.
7. Reconnect the negative battery cable.
8. Complete the “AFTER REPAIR PROCEDURE”.
(See F2–45 AFTER REPAIR PROCEDURE.)
Circuit Open/Short Inspection
1. Inspect the following wiring harnesses for open or
short (continuity check).
Open circuit
•If there is no continuity, the circuit is open.
Repair or replace the harness.
—Sedimentor switch terminal B (harness-
side) and GND.
—Sedimentor switch terminal A (harness-
side) and instrument cluster terminal 1C.
Short circuit
•If there is continuity, the circuit is shorted.
Repair of replace the harness.
—Sedimentor switch terminal A (harness-
side) and GND.
—Sedimentor switch terminal B (harness-
side) and power supply.
End Of Sie
Float Continuity
Up Yes
Down No
UP
DOWN
FLOATA
B
A6E40122015
1O 1M 1K 1I 1G 1E 1C 1A
1P 1N 1L 1J 1H 1F 1D 1B INSTRUMENT CLUSTER CONNECTOR
SEDIMENTOR SWITCH
HARNESS SIDE CONNECTOR
A
B
A6E40122016

F2–170
TROUBLESHOOTING
×: Applicable
Troubleshooting item
1 Melting of main or other fuses
2 MIL illuminates××
3 Will not crank
4 Hard start/long crank/erratic start/erratic crank× × ××××× ×
5 Engine stalls After start/at idle×××××××××
6 Cranks normally but will not start× × ×××× × ×
7 Slow return to idle××××
8 Engine runs rough/rolling idle× × ×××× ××
9 Fast idle/runs on××
10 Low idle/stalls during deceleration× × ×××× ×
11Engine stalls/quits Acceleration/cruise× ××××× ×
Engine runs rough Acceleration/cruise× ××××× ×
Misses Acceleration/cruise× ××××× ×
Buck/jerk Acceleration/cruise/ deceleration× ××××× ×
Hesitation/stumble Acceleration× ××××× ×
Surges Acceleration/cruise× ××××× ×
12 Lack/loss of power Acceleration/cruise× ××××× ×
13 Knocking/pinging××××
14 Poor fuel economy×××××××
15 Emissions compliance× ×××××××
16 High oil consumption/leakage
17 Cooling system concerns Overheating×
18 Cooling system concerns Runs cold
19 Excessive black smoke××××
20 Fuel odor (in engine compartment)×
21 Engine noise××××
22 Vibration concerns (engine)×××
23 A/C does not work sufficiently
24 A/C always on or A/C compressor runs continuously
25 A/C does not cut off under wide open throttle conditions
26 Constant voltage×
Fuel injectors malfunction (Leakage or clogging,
inoperative)Fuel leakage from fuel system (including insulator,
fuel injector)Fuel filter restriction or cloggingCMP sensor is damaged (e.g: open or short circuit)CMP sensor pulse wheel is damagedIDM or related circuit malfunctionExhaust system restriction or cloggingCatalyst converter malfunctionEGR system malfunctionEGR water cooler malfunctionV-reference voltage supply circuit malfunction

F2–176
TROUBLESHOOTING
NO.4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANKA6E408018881206
Diagnostic Procedure
4 HARD START/LONG CRANK/ERRATIC START/ERRATIC CRANK
DESCRIPTION•Starter cranks engine at normal speed but engine requires excessive cranking time before starting.
•Battery is in normal condition.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction or clogging
•Starting system malfunction
•Inadequate fuel pressure
•Fuel pressure limiter malfunction (built-in common rail)
•Suction control valve malfunction (built-in supply pump)
•Engine overheating
•Glow system malfunction
•Fuel filter clogging or restriction
•Fuel line clogging or restriction
•Fuel leakage
•Exhaust system and/or catalyst converter restriction or clogging
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Accelerator position sensor misadjustment
•MAF/IAT sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•IDM or related circuit malfunction
•EGR system malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1 Inspect for following:
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Intake-air system restriction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 1.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING”.
No Go to next step.
3 Connect WDS or equivalent to DLC-2.
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 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.

F2–178
TROUBLESHOOTING
End Of Sie
NO.5 ENGINE STALLS-AFTER START/AT IDLEA6E408018881207
Diagnostic Procedure
18 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
5 ENGINE STALLS-AFTER START/AT IDLE
DESCRIPTION•Engine stops unexpectedly.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction or clogging
•Engine overheating
•A/C system improper operation
•Immobilizer system (PATS) and/or circuit malfunction (if equipped)
•PCM control relay malfunction
•Glow system malfunction
•Inadequate fuel pressure
•Fuel pressure sensor related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel line clogging or restriction
•Fuel filter clogging or restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Exhaust system and/or catalyst converter restriction or clogging
•EGR system malfunction
•ECT sensor or related circuit malfunction
•Accelerator positions sensor or related circuit malfunction
•Accelerator positions sensor misadjustment
•MAF/IAT sensor or related circuit malfunction
•V-reference voltage supply circuit malfunction
•IDM or related circuit malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1Note
•The following test should be perform for
vehicles with immobilizer system. Go to
Step 10 for vehicles without immobilizer
system.
Connect WDS or equivalent to DLC-2.
Do following conditions appear?
•Engine is not completely started.
•DTC B1681 is displayed.YesBoth conditions appear:
Go to Step 4.
NoEither or other condition appears:
Go to next step.
2 Is coil connector securely connected to coil? Yes Go to next step.
No Connect coil connector securely.
Return to Step 1.
3 Does security light illuminate? Yes Go to next step.
No Inspect instrument cluster and wiring harness.

TROUBLESHOOTING
F2–179
F2
4 Connect WDS or equivalent to DLC-2 and
retrieve DTC.
DTC
B1213, B1342, B1600, B1601, B1602, B1681,
B2103, B2431Yes Go to appropriate DTC test.
No Go to next step.
5 Is there continuity between PCM GND terminals
65, 85, 103, 104 and GND?Yes Go to next step.
No Repair or replace wiring harness.
6 Measure voltage between PCM GND terminals
65, 85, 103, 104 and coil terminal C.
Is the voltage below 1.0?Yes Go to next step.
No Repair or replace wiring harness.
7 Turn engine switch to ON.
Access VPWR PID.
Is VPWR PID okay?
Specification
Battery voltageYes Go to next step.
No Repair or replace wiring harness.
8 Disconnect coil connector.
Turn engine switch to ON.
Is there battery voltage at coil connector terminal
D (harness-side)?Yes Inspect for following:
•Open or short circuit between coil terminal A and
PCM terminal 80
•Open or short circuit between coil terminal B and
PCM terminal 28
No Repair or replace wiring harness between coil
connector terminal D and fuse panel.
9 Is there continuity between PCM terminal 57 and
starter relay?Yes Go to next step.
No Repair replace wiring harness.
10 Inspect for following:
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Intake-air system restriction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 10.
11 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS-OVERHEATING”.
No Go to next step.
12Note
•Ignore DTC P0122, P0123, P0222 or
P0223 while performing this test.
Disconnect accelerator position sensor
connector.
Measure voltage at accelerator position sensor
connector VREF terminal (terminal D) with
engine switch ON.
Specification
4.5—5.5 V
Is voltage okay?Yes Go to next step.
No Go to symptom troubleshooting “NO.26 CONSTANT
VOLTAGE”.
13 Connect WDS or equivalent to DLC-2.
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.
14 Does engine start normally 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. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–181
F2
End Of Sie
NO.6 CRANKS NORMALLY BUT WILL NOT STARTA6E408018881208
Diagnostic Procedure
28 Inspect IDM.
(See F2–84 INJECTOR DRIVER MODULE
(IDM) INSPECTION)
Is IDM okay?Yes Go to next step.
No Repair or replace as necessary.
29 Inspect EGR system operation.
Is EGR system operation normal?Yes Remove and inspect supply pump and common rail.
No Repair or replace malfunctioning part according to
EGR system operation results.
30 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
6 CRANKS NORMALLY BUT WILL NOT START
DESCRIPTION•Starter cranks engine at normal speed but engine will not run.
•Refer to symptom troubleshooting “No.5 Engine stalls” if this symptom appears after engine stall.
•Fuel is in fuel tank.
•Battery is in normal condition.
POSSIBLE
CAUSE•Poor fuel quality
•Intake-air system restriction
•Fuel line restriction
•EGR system malfunction
•Glow system malfunction
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel filter clogging
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•V-reference supply circuit malfunction
•ECT sensor or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Immobilizer system (PATS) and/or circuit malfunction (if equipped)
•Low engine compression
•Improper valve timing
•IDM or related circuit malfunction
•PCM control repay malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1Note
•The following test should be perform for
vehicles with immobilizer system. Go to
Step 10 for vehicles without immobilizer
system.
Connect WDS or equivalent to DLC-2.
Do following conditions appear?
•Engine is not completely started.
•DTC B1681 is displayed.YesBoth conditions appear:
Go to Step 4.
NoEither or other condition appears:
Go to next step.
2 Is coil connector securely connected to coil? Yes Go to next step.
No Connect coil connector securely.
Return to Step 1.

F2–182
TROUBLESHOOTING
3 Does security light illuminate? Yes Go to next step.
No Inspect instrument cluster and wiring harness.
4 Connect WDS or equivalent to DLC-2 and
retrieve DTC.
DTC
B1213, B1342, B1600, B1601, B1602, B1681,
B2103, B2431Yes Go to appropriate DTC test.
No Go to next step.
5 Is there continuity between PCM GND terminals
65, 85, 103, 104 and GND?Yes Go to next step.
No Repair or replace wiring harness.
6 Measure voltage between PCM GND terminals
65, 85, 103, 104 and coil terminal C.
Is the voltage below 1.0?Yes Go to next step.
No Repair or replace wiring harness.
7 Turn engine switch to ON.
Access VPWR PID.
Is VPWR PID okay?
Specification
Battery voltageYes Go to next step.
No Repair or replace wiring harness.
8 Disconnect coil connector.
Turn engine switch to ON.
Is there battery voltage at coil connector terminal
D (harness-side)?Yes Inspect for following:
•Open or short circuit between coil terminal A and
PCM terminal 80
•Open or short circuit between coil terminal B and
PCM terminal 28
No Repair or replace wiring harness between coil
connector terminal D and fuse panel.
9 Is there continuity between PCM terminal 57 and
starter relay?Yes Go to next step.
No Repair replace wiring harness.
10 Inspect for following:
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Intake-air system restriction
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 10.
11Note
•Ignore DTC P0122, P0123, P0222 or
P0223 while performing this test.
Disconnect accelerator position sensor
connector.
Measure voltage at accelerator position sensor
connector VREF terminal (terminal D) with
engine switch ON.
Specification
4.5—5.5 V
Is voltage okay?Yes Go to next step.
No Go to symptom troubleshooting “NO.26 CONSTANT
VOLTAGE”.
12 Connect WDS or equivalent to DLC-2.
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. STEP INSPECTION RESULTS ACTION

F2–186
TROUBLESHOOTING
NO.8 ENGINE RUNS ROUGH/ROLLING IDLEA6E408018881210
Diagnostic Procedure
8 ENGINE RUNS ROUGH/ROLLING IDLE
DESCRIPTION•Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively.
•Idle speed is too slow and engine shakes excessively.
POSSIBLE
CAUSE•Poor fuel quality
•Air leakage from intake-air system
•Intake-air system restriction
•Incorrect idle speed
•Engine overheating
•Cooling fan No.1 system malfunction
•A/C system improper operation
•EGR system improper operation
•EGR water cooler malfunction
•Fuel leakage
•Inadequate fuel pressure
•Fuel pressure sensor or related circuit malfunction
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel filter clogging
•Fuel line restriction
•Incorrect fuel injection timing
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•ECT sensor or related circuit malfunction
•Idle switch misadjustment
•Idle switch or related circuit malfunction
•Accelerator position sensor misadjustment
•Accelerator position sensor or related circuit malfunction
•MAF/IAT sensor malfunction
•Neutral switch or related circuit malfunction
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Engine compression excessive unbalance for each cylinder
•Unbalanced fuel injection amount for each cylinder
•IDM or related circuit malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1 Inspect for following:
•Fuel quality (e.g.: including water
contamination, winter/summer blend)
•Fuel line/fuel filter clogging
•Loose bands on intake-air system
•Cracks on intake-air system parts
•Intake-air system restriction
•Vacuum leakage
•Cooling fan No.1 system operation
Are all items okay?Yes Go to next step.
No Service as necessary
Repeat Step 1.
2 Is engine overheating? Yes Go to symptom troubleshooting “NO.17 COOLING
SYSTEM CONCERNS—OVERHEATING.”
No Go to next step.

F2–190
TROUBLESHOOTING
NO.10 LOW IDLE/STALLS DURING DECELERATIONA6E408018881212
Diagnostic Procedure
10 LOW IDLE/STALLS DURING DECELERATION
DESCRIPTION•Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
POSSIBLE
CAUSE•Intake-air system restriction or clogging
•Poor fuel quality
•A/C system improper operation
•Inadequate fuel pressure
•Suction control valve malfunction (built-in supply pump)
•Fuel pressure limiter malfunction (built-in common rail)
•Fuel leakage
•Fuel line restriction or clogging
•Fuel filter restriction or clogging
•Incorrect fuel injection timing
•Incorrect idle speed
•Erratic signal from CKP sensor
•Erratic signal from CMP sensor
•Supply pump malfunction
•Fuel injector malfunction
•Low engine compression
•Improper valve timing
•Glow system malfunction
•EGR system malfunction
•MAF/IAT sensor or related circuit malfunction
•ECT sensor or related circuit malfunction
•Fuel pressure sensor or related circuit malfunction
•Neutral switch malfunction or related circuit malfunction
•Accelerator position sensor or related circuit malfunction
•Idle switch or related circuit malfunction
•Incorrect adjustment accelerator position sensor and/or idle switch
•IDM or related circuit malfunction
Warning
The following troubleshooting flow chart contains the fuel system diagnosis and repair
procedures. Read the following warnings before performing the fuel system services:
•Fuel vapor is hazardous. It can easily ignite, causing serious injury and damage. Always keep
sparks and flames away from fuel.
•Fuel line spills and leakage are dangerous. Fuel can ignite and cause serious injury or death
and damage. Fuel can also irritate skin and eyes. To prevent this, always complete “BEFORE
REPAIR PROCEDURE” and “AFTER REPAIR PROCEDURE” described in this manual.
STEP INSPECTION RESULTS ACTION
1 Does engine idle rough? Yes Go to symptom troubleshooting “NO.8 ENGINE RUNS
ROUGH/ROLLING IDLE”.
No Go to next step.
2 Inspect for following:
•Fuel line/fuel filter clogging or restriction
•Intake-air system restriction or clogging
•Fuel quality (e.g.: include water
contamination, winter/summer blend)
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 2.
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 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.