Mazda MX-6 1998, Workshop Manual

Page: 222 / 1282

TROUBLESHOOTING [ENGINE CONTROL KL]
STEP INSPECTION
ACTION
5 CHECK RESPONSE OF EGR BOOST
SENSOR TO MANUALLY APPLIED SIGNAL
•
Key off.
• Disconnect hose from EGR boost solenoid
to EGR boost sensor.
Check all vacuum lines connected to EGR
boost solenoids for damage, blockage, etc.
Service as necessary.
• Breakout box installed, PCM connected.
• Key on.
• Using hand held pump, slowly apply and
m aintain -71 k P a {-5 3 3 mmHg, -21 inHg},
while measuring EGR boost sensor voltage
response at Test Pin 34 of breakout box.
•
Is voltage response between 0.8 and 1.5
volts?
Yes
REMOVE vacuum pump.
RECONNECT all components.
Go to next step.
No REPLACE EGR boost sensor.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
e r After Repair Procedure
COMPLETE OBD II Drive Mode.
Confirm repair by performing EGR portion of OBD II drive
mode to check for DTCs.
6
CHECK POWER CIRCUIT AT EGR BOOST
SOLENOID
• Key off.
•
EGR boost solenoid disconnected.
• Key on, engine idling.
• Measure voltage between power circuit
and chassis ground at EGR boost solenoid
vehicle harness connector.
• Is EGR boost solenoid valve power
voltage greater than 10.5 volts?
Yes
Go to next step.
No SERVICE open in EGR boost solenoid power circuit.
RECONNECT all components.
RESET PCM to completely clear DTCs.
r r
After Repair Procedure
COMPLETE OBD II Drive Mode.
Confirm repair by performing EGR portion of OBD II drive
cycle to check for DTCs.
7 CHECK RESISTANCE OF EGR BOOST
SOLENOID
•
Key off.
•
EGR boost solenoid disconnected.
•
Measure solenoid resistance.
• Is re sista n ce betw een 30 and 70 ohm s?
Yes Go to next step.
No REPLACE EGR boost solenoid.
RESET PCM to completely clear DTCs.
x t
After Repair Procedure
COMPLETE OBD II Drive Mode.
Confirm repair by performing EGR portion of OBD II drive
cycle to check for DTCs.
8 CHECK EGR BOOST SOLENOID CIRCUIT
CONTINUITY
•
Key off.
•
EGR boost solenoid 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 98 at
breakout box and EGR boost solenoid
circuit at solenoid vehicle harness
connector.
•
Is resistance less than 5.0 ohms?
Yes Go to next step.
No SERVICE open in EGR boost solenoid harness circuit.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
tr
After Repair Procedure
COMPLETE OBD II Drive Mode.
Confirm repair by performing EGR portion of OBD II drive
mode to check for DTCs.
9 CHECK EGR BOOST SOLENOID CIRCUIT
FOR SHORT TO POWER AND GROUND
•
Key off.
•
EGR boost solenoid disconnected.
• Breakout box installed, PCM disconnected.
•
Measure resistance between Test Pin 98
and Test Pins 71, 97 and 90 at breakout
box.
•
Measure resistance between Test Pin 98
and Test Pins 51, 103 and 91 at breakout
box.
•
Is each resistance greater than 10,000
ohms?
Yes REMOVE breakout box.
RECONNECT all components.
Go to next step.
No SERVICE short in EGR boost solenoid harness circuit.
REMOVE breakout box.
RECONNECT all components.
RESET PCM to completely clear DTCs.
i t
After Repair Procedure
COMPLETE OBD II Drive Mode.
Confirm repair by performing EGR portion of OBD II drive
mode to check for DTCs.
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