Mazda MX-6 1998, Workshop Manual

Page: 327 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
DTC P1621 Code word does not match after engine cranking
DESCRIPTION • Code word stored in PCM and Immobilizer unit does not match.
[Possible Cause]
• Transformation of code word stored in Immobilizer unit. • Transformation of code word stored in PCM.
STEP
INSPECTION ACTION
1
CHECK DTC PRESENT
• RESET PCM to completely clear DTCs.
c r 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 DTC P1602 PRESENT
• Does P1602 present?
Yes
Go to DTC P1603 inspection.
No Replace IU and reprogram immobilizer system.
ep
0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAMMING
PROCEDURE, Immobilizer Replacement
Go to next step.
3 CHECK DTC REPRESENT
• Does engine start after replacing IU and
clearing DTC?
Yes
Troubleshooting is completed.
No
Replace PCM and reprogram immobilizer system.
D* 0 9-14 IMMOBILIZER SYSTEM REPROGRAMMING
PROCEDURE, PCM Replacement
DTC P1622 Key ID number does not match
DESCRIPTION
• ID number stored in immobilizer unit (IU) and PCM does not match. This DTC is indicated
only after immobilizer unit Is replaced and reprogramming system.
[Possible Cause]
• Unregistered key is used in step 3 of immobilizer system • Transformation of key ID number stored in PCM.
reprogram procedure (IU replacement).
STEP
INSPECTION ACTION
1
CHECK DTC PRESENT
• RESET PCM to completely clear DTCs.
tr 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 ENGINE IS STARTING NORMALLY
USING ANOTHER REGISTERED KEY
• Does engine start with another
registered key?
Yes Previous key is defective. Discard it.
No
Replace PCM and reprogram immobilizer system.
u- 0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAMMING
PROCEDURE, PCM Replacement
Note
• Do n o t use P C M on o th e r v e h ic le fo r te s tin g . D ia g n o s tic tro u b le c o d e No. P 1 6 2 2 w ill be d is p la y e d a g a in .
DTC P1623 Code word or key ID number write/read error in PCM
DESCRIPTION
• PCM internal EEPROM damaged
[Possible Cause]
• PCM internal EEPROM damaged
STEP
INSPECTION
ACTION
1
CHECK DTC PRESENT
• RESET PCM to completely clear DTCs.
tr After Repair Procedure
• RERUN OBD test.
• Is same DTC present after cranking?
Yes Replace
PCM
and reprogram Immobilizer system,
c r 0 9 -1 4 IMMOBILIZER SYSTEM REPROGRAMMING
PROCEDURE, PCM Replacement
No
Different DTC displayed:
Go to appropriate DTC inspection.
No DTC displayed:
Troubleshooting Is completed.
01-01B-121