Mazda MX-6 1998, Workshop Manual

Page: 261 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
DTC P0340
Camshaft position (CMP) sensor circuit malfunction
DESCRIPTION • DTC P0340 indicates that self-test has detected CMP sensor circuit failure
[Possible Cause]
• CMP sensor circuit open • CMP sensor power circuit open
• CMP sensor circuit shorted to ground • Damaged CMP Sensor
• CMP sensor circuit shorted to power • Damaged PCM
• CMP sensor ground open
STEP INSPECTION
ACTION
1 START ENGINE
• Start engine.
• Will engine start?
Yes Go to next step.
No
DTC P0340 is not cause of no start.
Go to ENGINE SYMPTOM TROUBLESHOOTING No.5.
2 CLEAR AND ATTEMPT TO RE-GENERATE
DTC P0340
• RESET PCM to completely clear DTCs.
tpr After Repair Procedure
• COMPLETE OBD II Drive Mode.
• Start engine.
• Increase rpm to greater than 1,500 rpm for
10 seconds. Repeat two times.
• Key off.
• Retrieve all Continuous Memory DTCs.
•
Is DTC P0340 present?
Yes Go to next step.
No Fault that produced DTC P0340 is intermittent.
Intermittent poor connection or component malfunction
(REPAIR or REPLACE as necessary).
Go to ENGINE SYMPTOM TROUBLESHOOTING No.27.
3
CHECK POWER CIRCUIT TO CMP SENSOR
• Key off.
• Disconnect CMP sensor vehicle harness
connector.
• Key on, engine off.
• Measure voltage between power circuit at
CMP sensor vehicle harness connector
and battery negative post.
• Is voltage greater than 1 0.5 volts?
Yes Go to next step.
No SERVICE open in CMP sensor power circuit.
RECONNECT all components.
COMPLETE PCM.
RESET PCM to completely clear DTCs.
i
t
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
4
CHECK GROUND CIRCUIT TO CMP
SENSOR
• Key off.
• CMP sensor disconnected.
• Measure resistance between ground circuit
at CMP sensor vehicle harness connector
and battery negative post.
• Is resistance less than 5.0 ohms?
Yes Go to next step.
No
SERVICE open in CMP sensor ground circuit.
COMPLETE PCM.
RESET PCM to completely clear DTCs.
t r After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
5 CHECK CONTINUITY TO PCM
• Key off.
• CMP sensor disconnected.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion, loose wires,
etc. Service as necessary.
• Install breakout box.
• Measure resistance between signal circuit
at CMP sensor vehicle harness connector
and Test Pin 85 and 8 at breakout box.
• Are resistance measurements less than
5.0 ohms?
Yes Go to next step.
No SERVICE open circuit.
REMOVE breakout box.
RECONNECT all components.
RERUN OBD Test.
6 CHECK CMP SIGNAL CIRCUIT FOR SHORT
TO POWER
• Key off.
• CMP sensor disconnected.
• Breakout box installed.
• Key on, engine off.
• Measure voltage between Test Pin 85 and
Test Pins 51 and 103 at breakout box.
• Is voltage less than 1.0 volt?
Yes Go to next step.
No
SERVICE CMP circuit for short to power.
REMOVE breakout box.
RECONNECT all components.
RERUN OBD Test.
0 1 -0 1 B -5 5