wiring MAZDA 6 2002 Suplement Repair Manual

F2–160
ON-BOARD DIAGNOSTIC
DTC P0850A6E407001082243
Diagnostic procedure
DTC P0850 Neutral switch circuit malfunction
DETECTION
CONDITION•PCM monitors input voltage from neutral switch while engine is running. If input voltage from neutral switch
does not change when vehicle stops after accelerating to above 60 km/h {37 mph} and decelerating to 0
km/h {0 mph} two times, PCM determines neutral switch circuit malfunction.
POSSIBLE
CAUSE•Neutral switch malfunction
•Connector or terminal malfunction
•Short to GND in wiring between neutral switch terminal A and PCM terminal 56
•Open circuit in wiring between neutral switch terminal B and GND
•Open circuit in wiring between neutral switch terminal A and PCM terminal 56
•PCM malfunction
STEP INSPECTION ACTION
1VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Information
availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available Service
Information.
•If vehicle is not repaired, go to next step.
No Go to next step.
2CLASSIFY MALFUNCTION OF SHORT TO GND
OR OPEN
•Turn engine switch to ON (Engine OFF).
•Engage gear.
•Access CPP/PNP PID using WDS or
equivalent.
•Is CPP/PNP PID OFF?Yes Go to Step 5.
No Go to next step.
A
B
A
B NEUTRAL SWITCH
56PCM
56
3
6
5
5
7
498
NEUTRAL SWITCH
HARNESS SIDE CONNECTORPCM
HARNESS SIDE CONNECTOR

F2–162
ON-BOARD DIAGNOSTIC
DTC P1190A6E407001083201
Diagnostic procedure
DTC P1190 Calibration resistor circuit malfunction
DETECTION
CONDITION•PCM monitors input voltage from calibration resistor while engine is running. If input voltage from
calibration resistor is below 0.2 V or above 4.8 V, PCM determines calibration resistor circuit malfunction.
POSSIBLE
CAUSE•Calibration resistor malfunction
•Connector or terminal malfunction
•Short to GND in wiring between calibration resistor terminal A and PCM terminal 37, 62, 89, 11
•Short to power circuit in wiring between calibration resistor terminal A and PCM terminal 37, 62, 89, 11
•Open circuit in wiring between calibration resistor terminal A and PCM terminal 37, 62, 89, 11
•Open circuit in wiring between calibration resistor terminal C and PCM terminal 91
•PCM malfunction
STEP INSPECTION ACTION
1VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•Check for related Service Information
availability.
•Is any related repair information available?Yes Perform repair or diagnosis according to available Service
Information.
•If vehicle is not repaired, go to next step.
No Go to next step.
A
C
C
A
DBPCM
HARNESS SIDE CONNECTOR91PCM
CALIBRATION RESISTOR
5
2
2
5437
7
6
6
11 37
62 89
91
37 (NO.1 CYLINDER)
62 (NO.2 CYLINDER)
89 (NO.3 CYLINDER)
11 (NO.4 CYLINDER)
CALIBRATION RESISTOR
HARNESS SIDE CONNECTOR

TROUBLESHOOTING
F2–173
F2
NO.1 MELTING OF MAIN OR OTHER FUSESA6E408018881203
End Of Sie
1 Melting of main or other fuses
[TROUBLESHOOTING HINTS]
Inspect condition of fuse.
Damaged fuse Related wiring harness
MAINMAIN fuse
•BTN fuse
•FAN fuse
•AD FAN fuse
•IG KEY 2 fuse
IG KEY 1IG KEY 1 fuse
•Engine switch
—ENGINE fuse
FUEL PUMPFUEL PUMP fuse
•Fuel warmer
•PCM control relay
BTNBTN fuse
•ROOM fuse
IG KEY 2IG KEY 2 fuse
•Engine switch
ROOMROOM fuse
•DLC-2
ENGINEENGINE fuse
•PCM
INJINJ fuse
•PCM
•IDM
•MAF/IAT sensor
•VSC solenoid valve
•VBC solenoid valve
•EGR control solenoid valve
•EGR solenoid valve (vacuum)
•EGR solenoid valve (vent)
•Intake shutter solenoid valve (half)
•Intake shutter solenoid valve (full)
GLOWGLOW fuse
•Glow plug relay
—Glow plug
—GLOW SIG
ENG+BENG+B fuse
•PCM
FANFAN fuse
•Cooling fan relay No.2
AD FANAD FAN fuse
•Cooling fan relay No.1
Shorted harness
Repair shorted harness and replace fuseFuseDeterioration
Replace fuse

F2–174
TROUBLESHOOTING
NO.2 MIL ILLUMINATESA6E408018881204
Diagnostic procedure
End Of Sie
NO.3 WILL NOT CRANKA6E408018881205
Diagnostic procedure
2 MIL ILLUMINATES
DESCRIPTION•MIL illuminates incorrectly.
POSSIBLE
CAUSE•PCM illuminates for emission-related concern (DTC is stored in PCM)
•Instrument cluster malfunction
Note
•If MIL blinks at steady rate, misfire condition could possibly exist.
STEP INSPECTION RESULTS ACTION
1 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.
NoNo DTC is displayed:
•Inspect instrument cluster operation.
2 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)
3 WILL NOT CRANK
DESCRIPTION•Starter does not work.
POSSIBLE
CAUSE•Open starter circuit between engine switch and starter
•Starter malfunction
•Seized/hydrolocked engine, flywheel
•Immobilizer system (PATS) and/or circuit malfunction (if equipped)
•Low or dead battery
•Charging system malfunction
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.
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.

TROUBLESHOOTING
F2–175
F2
End Of Sie
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 following:
•Battery connection
•Battery condition
•Fuses
Are all items okay?Yes Go to next step.
No Service as necessary.
Repeat Step 10.
11 Is clicking sound heard from starter when engine
switch is turned to START?Yes Go to Step 13.
No Go to next step.
12 Inspect starting system.
Is starting system okay?Yes Inspect for seized/hydrolocked engine, flywheel.
No Repair or replace components as required.
13 Do any other electrical accessories work? Yes Go to next step.
No Inspect charging system.
14 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:
Inspect for following:
•START circuit in engine switch
•Open circuit between engine switch and starter
15 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

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

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

F2–218
TROUBLESHOOTING
6 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 appropriate DTC test.
7 Access ECT PID.
Inspect ECT PID while warming up engine.
Is PID value correct?Yes Go to next step.
No Inspect ECT sensor and related wiring harnesses.
8 Access IAT PID.
Inspect IAT PID while running engine.
Is PID value correct?Yes Go to next step.
No Inspect IAT sensor and related wiring harnesses.
9 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.
10 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.
11 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.
12 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.
13 Remove parts necessary to inspect
turbocharger.
Note
•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. STEP INSPECTION RESULTS ACTION

TROUBLESHOOTING
F2–227
F2
INTERMITTENT CONCERN TROUBLESHOOTINGA6E408018881229Vibration Method
1. If a malfunction occurs or becomes worse while driving on a rough road, or due to engine vibration, perform the
steps below.
Note
•There are several reasons vehicle or engine vibration could cause an electrical malfunction. Some of the
things to check for are:
—Connectors not fully seated.
—Wire harnesses not having full play.
—Wires laying across brackets or moving parts.
—Wires routed too close to hot parts.
•An improperly routed, improperly clamped, or loose harness can cause wiring to become pinched
between parts.
•The connector joints, points of vibration, and places where wire harnesses pass through the fire wall, body
panels, etc. are the major areas to be checked.
Inspection Method for Switch Connectors or Wires
1. Connect the WDS or equivalent to the DLC-2.
2. Turn the engine switch to ON (Engine OFF).
Note
•If engine starts and runs, perform the following steps at idle.
3. Access PIDs for the switch you are inspecting.
4. Turn switch on manually.
5. Shake each connector or wire harness a bit
vertically and horizontally while monitoring the
PID.
•If the PID value is unstable, check for poor
connection.
Inspection Method for Sensor Connectors or Wires
1. Connect the WDS or equivalent to the DLC-2.
2. Turn the engine switch to ON (Engine OFF).
Note
•If engine starts and runs, perform the following steps at idle.
3. Access PIDs for the switch you are inspecting.
4. Shake each connector or wire harness a bit
vertically and horizontally while monitoring the
PID.
•If the PID value is unstable, check for poor
connection.
A6E40802001
A6E40802002