Mazda MX-6 1998, Workshop Manual, Page: 245 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
STEP INSPECTION
ACTION
10 CHECK FOR SHORTS TO VOLTAGE
SOURCE IN HARNESS CIRCUIT
• Key off.
• Disconnect NGS tester from DLC.
• Suspect sensor disconnected.
• Disconnect PCM. Inspect for damaged or
pushed out pins, corrosion and loose wires.
Service as necessary.
• Install breakout box. Leave PCM
disconnected.
• Use following list to measure resistance
between appropriate test pins at breakout
box:
• DTC P1130, P1132=H02S (Front RH)
Test Pin 60 and Test Pins 71, 93 and 97.
• DTC P1150, P1152=H02S (Front LH)
Test Pin 87 and Test Pins 71, 94 and 97.
• Is resistance greater than 10,000 ohms?
Yes REMOVE breakout box.
REPLACE PCM.
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No REPLACE heated oxygen sensor.
SERVICE short to power.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
tr After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
11 CHECK FOR HEATED OXYGEN SENSOR
SIGNAL SHORTED TO HEATED OXYGEN
SENSOR HEATER CIRCUIT IN SENSOR
• Key off.
• Connect suspected heated oxygen sensor.
• NGS tester connected.
• Key on, engine off.
Note
• heated oxygen sensor displayed as 0 2 S 1 1
(Front RH) or 02S21 (Front LH) on NGS
tester.
• Access suspected heated oxygen sensor
PID corresponding to DTCs received.
• Is heated oxygen sensor voltage greater
than 0.45 volt?
Yes REPLACE heated oxygen sensor.
RECONNECT all components.
RESET PCM to completely clear DTCs.
ef
After Repair Procedure
COMPLETE OBD II Drive Mode.
RERUN OBD Test.
No RECONNECT all components.
Go to next step.
12
CHECK FUEL PRESSURE
• Key off.
• Install fuel pressure gauge.
• Verify vacuum source to fuel pressure
regulator.
• If engine will start:
• Start engine and idle. Record fuel pressure.
• Increase engine speed to 2,500 rpm and
maintain for one minute. Record fuel
pressure.
•
No start:
• Cycle key on and off several times. Record
fuel pressure.
• Is fuel pressure between 207 — 301 kPa
{2.1— 2.9 kgf/cm2, 30 — 45 psi} for all
others?
Yes
Fuel system is capable of required fuel pressure.
Go to step 22.
No
Fuel pressure out of specification.
Go to next step.
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