Chery A21 2005, Service Manual, Page: 355 / 475

CHERY
·
A21 SERVICE MANUAL ENGINE EFI SYSTEM
32
unreasonable failure
4.2 DIAGNOSIS FLOW WHEN THERE IS DIFFERENT DTC
P0107 Much lower voltage of the air intake pressure sensor
No. Operating steps Result Follow up steps
1
Connect the diagnostic tester and commutator, put the
ignition switch to
“
ON
”
Next step
Yes To step No. 5
2
Observe
“
air intake pressure
”
item in data flow, if it is
about 101kpa (specific data is correlated to that time
air pressure).
No Next steps
Yes To step No. 5
3
Take off the joint of cable air intake pressure sensor,
check the voltage between pin No. 3 and pin No. 1 by
multimeter and look if it is around 5V.
No Next step
Yes
Repair or replace
cable 4
Check if it is short circuit to ground between ECU pin
No. 17, No. 33, No. 37 and sensor connector No.1,
No.3 and No. 4.
No Next step
Yes Diagnosis help
5
Start the engine at idle speed. Step on the accelerator
slowly approach to open completely and observe the
value changes of diagnostic tester
“
air intake
pressure
”
, the changes should be not big; step on the
accelerator quickly to complete open, the displayed
value should be reach up to 90kpa instantaneous.
No Replace the sensor
DTC: P0108 Much higher voltage of the air intake pressure sensor
No. Operating steps Result Follow up steps
1
Connect the diagnostic tester and commutator, put the
ignition switch to
“
ON
”
Next step
Yes To step No. 5
2
Observe
“
air intake pressure
”
item in data flow, if it is
about 101kpa(specific data is correlated to that time air
pressure)
No Next steps
Yes To step No. 5
3
Take off the joint of cable air intake pressure sensor,
check the voltage between pin No. 3 and pin No. 1 by
multimeter and look if it is around 5V.
No Next step
Yes
Repair or replace
cable
4
Check if it is open circuit or short circuit to power supply
between ECU pin No. 17, No. 33, No. 37 and sensor
connector No.1, No.3 and No. 4.
No Next step
Yes Diagnosis help
5
Start the engine at idle speed. Step on the accelerator
slowly approach to open completely and observe the
value changes of diagnostic tester
“
air intake pressure
”
,
the changes should be not big; step on the accelerator
quickly to complete open, the displayed value should be
reach up to 90kpa instantaneous.
No
Replace the
sensor
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