Mazda MX-6 1998, Workshop Manual

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TROUBLESHOOTING [ENGINE CONTROL KL]
DTC P1652
IAC valve monitor disable by PSP switch failed on
DESCRIPTION
• DTC P1652 indicates Power steering pressure (PSP) switch is always on at IAC system
monitoring condition
[Possible Cause]
• Damaged PSP switch • PSP signal circuit short to ground
• Damaged PCM
STEP INSPECTION
ACTION
1
VERIFY ELECTRICAL FUNCTION
• Key on, engine off.
• View PSP PID with NGS tester while
turning steering wheel.
• Does PSP PID indicate 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 it Idle.
• View RPM PID with NGS tester.
• Disconnect PSP switch vehicle harness
connector.
• Does engine rpm decrease?
Yes
Go to step
No
Go to next step.
3 CHECK CONTINUITY OF PSP CIRCUIT
• Key off.
• PSP switch disconnected.
• Disconnect PCM. Inspect for damage 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 switch vehicle
harness connector.
• Is resistance less than 5.0 ohms?
Yes Go to next step.
No SERVICE open circuit.
REMOVE breakout box.
RECONNECT all component.
RESET PCM to completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
4 CHECK PSP SWITCH RESISTANCE
• Key off.
• PSP switch disconnected.
• Measure resistance between PSP switch
terminal and chassis ground while turning
steering wheel.
• Is resistance less than 5.0 ohms?
Yes Go to next step.
No
REPLACE PSP switch.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
it
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
5
CHECK POWER STEERING FLUID
PRESSURE
• Key off.
• Measure power steering fluid pressure.
tr 0 6-12 POWER STEERING FLUID
INSPECTION, Fluid Pressure Inspection
• Is power steering fluid pressure
specified?
Yes REPLACE PCM.
RERUN OBD Test.
No REPAIR or REPLACE engine speed sensing power
steering system.
RERUN OBD Test.
0 1 -0 1 B -1 24