Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL FS]
DTC P1624
Immobilizer system communication counter = 0
DESCRIPTION
• PCM detected immobilizer system malfunction more than three times.
[Possible Cause]
• Engine was attempted to start more than three times
under malfunction.
STEP INSPECTION ACTION
1
CHECK DTC P1624 PRESENT
• RESET PCM to completely clear DTCs.
zr After Repair Procedure
• RERUN OBD test.
• Is P1624 still present after cranking?
Yes Go to next step.
No Troubleshooting is completed.
2
CHECK DTC PRESENT
• Is there another DTC.
Yes
Go to other DTC inspection.
No Go to ENGINE SYMPTOM TROUBLESHOOTING No.5.
DTC P1650
Power steering pressure (PSP) switch out of self-test range
DESCRIPTION • DTC P1650 indicates PSP signal is out of self-test range
[Possible Cause]
• PSP switch/shorting bar damaged • PCM damaged
• Power steering pressure switch open or shorted to
ground
STEP
INSPECTION
ACTION
1 VERIFY ELECTRICAL FUNCTION
• Key on, engine running.
• View PSP PID while turning steering wheel
back and forth.
• Does the PSP PID indicate voltage
Low/High or High/Low?
Yes
Intermittent poor connection or component malfunction
(REPAIR or REPLACE as necessary).
No Go to next step.
2
CHECK PSP SWITCH OPERATION
• Key off.
• Start engine and let idle in Park/Neutral.
• Install dwell tacho tester.
• Disconnect PSP switch connector and
inspect end for damage. Service as
necessary.
• Jumper PSP signal circuit to ground at PSP
connector.
• Does engine rpm increase?
Yes REPLACE PSP switch.
VERIFY repair.
No REMOVE jumper.
Go to next step.
3
CHECK CONTINUITY OF PSP CIRCUITS
• Key off.
• PSP switch disconnected.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion, loose wires,
etc. Service as necessary.
• Install breakout box. Leave PCM
disconnected.
• Measure resistance between Test Pin 31 at
breakout box and PSP circuit at PSP
switch connector.
• Is each resistance less than 5.0 ohms?
Yes Go to next step.
No
SERVICE open circuit.
REMOVE breakout box.
RECONNECT all components.
RERUN OBD Test.
4 CHECK PSP CIRCUIT FOR SHORT
• Key off.
• PSP switch disconnected.
• Breakout box installed. Leave PCM
disconnected.
• Measure resistance between Test Pin 31
and Test Pin 91 at breakout box.
• Measure resistance between Test Pin 31 at
breakout box chassis ground.
• Is either resistance less than 10,000
ohms?
Yes SERVICE short in harness.
REMOVE
breakout box.
RECONNECT all components.
VERIFY repair.
No Go to next step.
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