Mazda 6 2002, Workshop Manual

Page: 273 / 1248

ON-BOARD DIAGNOSTIC
F–143
F
3 VERIFY CURRENT INPUT SIGNAL STATUS-IS
CONCERN INTERMITTENT OR CONSTANT
•
Connect WDS or equivalent to DLC-2.
•
Start engine.
•
Access VSS PID using WDS or equivalent.
— Vehicle speed
20 km/h {12.4 mph}: 20km/
h {12.4 mph}
— Vehicle speed 40 km/h {24.8 mph}: 40km/
h {24.8 mph}
•
Are PID readings within specification?
Yes Go to intermittent concern troubleshooting procedure.
(See F–227 INTERMITTENT CONCERN
TROUBLESHOOTING .)
No Go to next step.
4 INSPECT POOR CONNECTION OF VSS
CONNECTOR
•
Verify that the VSS connector is connected
securely.
•
Is connector okay?
Yes Go to next step.
No Reconnect the connector, then go to Step 11.
5 INSPECT VSS
•
Perform VSS inspection.
(See
J–5 VEHICLE SPEEDOMETER
SENSOR INSPECTION )
•
Is VSS okay?
Yes Go to next step.
No Replace VSS, then go to Step 11.
6 INSPECT VSS CIRCUIT FOR SHORT TO
POWER
•
Turn ignition key OFF
•
Disconnect VSS connector.
•
Turn ignition key ON (Engine OFF)
•
Measure voltage following terminals:
— VSS terminal A
— VSS terminal B
•
Is any voltage reading?
Yes Repair or replace suspected harness, then go to Step 11.
No Go to next step.
7 INSPECT VSS CIRCUIT FOR SHORT TO
GROUND
•
Inspect continuity between following terminal
and body ground:
— VSS terminal A
— VSS terminal B
•
Is there any continuity?
Yes Repair or replace suspected harness, then go to Step 11.
No Go to next step.
8 INSPECT VSS CIRCUITS FOR SHORTS
•
Inspect continuity between VSS connector
terminals A and B.
•
Is there any continuity?
Yes Repair or replace suspected harness, then go to Step 11.
No Go to next step.
9 INSPECT POOR CONNECTION OF PCM
CONNECTOR
•
Disconnect PCM connector.
•
Inspect for poor connection (damaged, pulled-
out terminals, corrosion, etc.).
•
Is there any malfunction?
Yes Repair terminal, then go to Step 11.
No Go to next step.
10 INSPECT VSS CIRCUIT FOR OPEN CIRCUIT
•
Inspect continuity between following circuits:
— VSS terminal A and PCM terminal 2I
— VSS terminal B and PCM terminal 2L
•
Is there continuity?
Yes Inspect VSS pulse wheel for damage. Replace VSS pulse
wheel and go to next step.
No Repair or replace suspected harness, then go to next step.
STEP INSPECTION ACTION