Downloaded from www.Manualslib.com manuals search engine Diagnostic Procedure
1.CHECK EXHAUST GAS LEAK
• Start engine and run it at idle.
• Listen exhaust gas leak before three way catalyst.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace.
2.CHECK ECM CONTROL SIGNAL IN DATA STREAM
• With the X-431, select view data stream.
REFERENCE DATA
MONITOR ITEM CONDITION DATA
Injector pulse •
Engine: warm up
• Shift: P or N
• Air condition: Off
• No load Idle
Approximately 2.5 ms
Is the check result normal?
Ye s>>Go to step 5.
No
>>Go to the next step.
3.CHECK UPSTREAM O2SENSOR ELECTRICAL CONNECTOR
• Turn ignition switch off.
• Disconnect the upstream O
2sensor (1) electrical
connector.
• Inspect the electrical connector for damage.
Is the electrical connector OK?
Ye s>>Go to the next step.
No
>>Repair or replace the electrical connector
as necessary.
4.CHECK UPSTREAM O2SENSOR SIGNAL CIRCUIT
• Disconnect ECM harness connector.
• Check harness continuity between the following terminals.
UPSTREAM O2SENSOR ECM TERMINAL O2SENSOR TERMINAL
O
2sensor 1 36 3
18
4
DIAGNOSIS & TESTING
BESM030017
03–340Chery Automobile Co., Ltd.
Downloaded from www.Manualslib.com manuals search engine •Continuity should exist.
• Also check harness for short to power.
Is the check result normal?
Ye s>>Go to the next step.
No
>>Repair or replace the circuit for an open or short to power in harness or connectors.
5.CHECK FUEL PRESSURE
• Release fuel pressure to zero.
• Install fuel pressure gauge (2) and check fuel
pressure.
• Observe the following fuel pressures when testing (See Fuel Pressure Test in Section 04 Fuel Delivery)
FUEL PRESSURES
Key On 400 kPa (4 bar)
Key Off 380 kPa (3.8 bar) in 10 minutes
Engine Idle 400 kPa (4.0 bar) - 420 kPa (4.2 bar)
Is the check result normal?
Ye s>>Go to step 7.
No
>>Go to the next step.
DIAGNOSIS & TESTING
BESM030020
03
03–341Chery Automobile Co., Ltd.