Mazda MX-6 1998, Workshop Manual

Page: 114 / 1282

TROUBLESHOOTING [ENGINE CONTROL FS]
DTC P1001 Active self-test standard protocol communication error
DESCRIPTION
• KOER self-test cannot be completed
[Possible Cause]
• Damaged DLC • Open in DLC harness circuit
• Incorrect self test activation method • Short in DLC harness circuit
• Constant voltage is not in specification • Damaged main relay circuit
• Idle RPM out of specification • Damaged PCM
STEP INSPECTION
ACTION
1 VERIFY SELF TEST ACTIVATION METHOD
• Key off.
• Disconnect NGS tester from DLC. Inspect
DLC for damage. Service as necessary.
• Verify that the correct procedure was used
to activate Continuous Memory, KOEO or
KOER self-test.
• Was the correct self-test activation
method used?
Yes
Go to next step.
No COMPLETE self test using correct procedure.
2 CHECK FOR CONSTANT VOLTAGE AT TP
SENSOR
• Key off.
• TP sensor disconnected.
• Key on, engine off.
• Measure voltage between constant voltage
and TP sensor ground circuits at TP sensor
connector.
• Key off.
•
Was voltage between 4.0 and 6.0 volts?
Yes RECONNECT TP sensor.
Go to next step.
No REPAIR open in constant voltage circuit.
RECONNECT TP sensor.
3 ABILITY TO ACCESS CONTINUOUS
MEMORY DTCs
• Could Continuous Memory DTCs be
accessed before this OBD Test was
entered?
Yes Go to next step.
No Go to step 6.
4 ABILITY TO ACTIVATE KOEO SELF-TEST
• Could KOEO self-test be activated and
completed before this OBD Test was
entered?
Yes Go to next step.
No Go to step 6.
5 ABILITY TO ACTIVATE KOER SELF-TEST
• Could KOER self-test be activated and
completed before this OBD Test was
entered?
Yes CHECK that correct PCM is installed on vehicle.
No Go to next step.
01-01A-86