Mazda MX-6 1998, Workshop Manual

Page: 1027 / 1282

TROUBLESHOOTING [IMMOBILIZER SYSTEM]
STEP INSPECTION
ACTION
Connect PCM connector.
Turn ignition switch to ON.
Measure voltage at terminal A at immobilizer unit
connector of wiring harness.
Is voltage more than 10 V?
IMMOBILIZER UNIT
CONNECTOR
M K
X
E C
N L J H F D B
W 6 U 9 0 1 W G 5
Yes
No
Replace immobilizer unit and reprogram immobilizer
system.
n- 0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAM
PROCEDURE, Immobilizer Unit Replacement
Note
• Confirm that the voltage at the terminal L of the
immobilizer unit connector is more th a n 10 V when
turning the ignition switch to ON after repairing the
malfucntion of DTC 24. If not specified, repair the wiring
harness between ENGINE fuse and the immobilizer
unit.
Replace PCM and reprogram immobilizer system.
zt
0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAM
PROCEDURE, PCM Replacement
Note
• Confirm that the voltage at the terminal L of the
immobilizer unit connector is more th a n 10 V when
turning the ignition switch to ON after repairing the
malfucntion of DTC 24. If not specified, repair the wiring
harness between ENGINE fuse and the immobilizer
unit.
DTC 30
Immobilizer unit— PCM communication error
POSSIBLE
CAUSE
• Defective immobilizer unit
• Defective PCM
STEP INSPECTION ACTION
Replace immobilizer unit and reprogram
immobilizer system.
p r 0 9 -1 4 IMMOBILIZER SYSTEM
REPROGRAM PROCEDURE, Immobilizer
Unit Replacement
Does engine start?
Yes Immobilizer unit was defective.
No
Replace PCM and reprogram immobilizer system.
D- 0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAM
PROCEDURE, PCM Replacement
DTC P1602 Immobilizer unit (IU) — PCM communication error
DESCRIPTION * Command transmission from PCM to IU exceed limit
• No response from IU
[Possible Cause]
• Defective wiring harness • Defective coil
• Defective IU • Defective key (transponder)
• Defective PCM
STEP INSPECTION ACTION
1 CHECK DTC PRESENT
• RESET PCM to completely clear DTCs.
o* After Repair Procedure
• RERUN OBD test.
• Is same DTC present after cranking?
Yes Go to next step.
No
Different DTC displayed:
Go to appropriate DTC inspection.
No DTC displayed:
Troubleshooting is completed.
2 CHECK IMMOBILIZER SYSTEM DTC PRESENT
• Does security light indicate DTC 01?
Yes Go to DTC 01 inspection.
No Go to next step.
3
CHECK IMMOBILIZER SYSTEM DTC PRESENT
• Does security light indicate DTC 03?
Yes Go to DTC 03 inspection.
No Go to next step.
4 CHECK IMMOBILIZER SYSTEM DTC PRESENT
• Is other DTC present except P1624?
Yes
Go to other DTC inspection.
No Go to next step.
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