Daewoo MATIZ Service Manual page 206

1F – 108 ENGINE CONTROLS
Step
1. Visually/physically inspect the following items for
vacuum leaks:
D Intake manifold.
D Throttle body.
9
D Injector O-rings.
2. Repair any leaks found as necessary.
Is the repair complete?
Allow the engine to idle.
10
Are the Idle Air Control (IAC) counts above the
specified value?
Check the fuel for excessive water, alcohol, or other
contaminants and correct the contaminated fuel
11
condition if present.
Is the repair complete?
Check the IAC valve performance. Refer to "DTC
P0506 Idle Speed RPM Lower Than Desired Idle
Speed" or "DTC P0507 Idle Speed RPM Higher
12
Than Desired Idle Speed" in this section and repair
as necessary.
Is the repair complete?
1. Connect a fuel pressure gauge to the fuel system.
2. Turn the ignition OFF for at least 10 seconds.
3. Turn the ignition ON, with the engine OFF. The
fuel pump will run for approximately 2–3 seconds.
It may be necessary to cycle the ignition switch
ON more than once to obtain maximum fuel
13 pressure.
4. Note the fuel pressure with the fuel pump running.
The pressure should be within the specified value.
When the fuel pump stops, the pressure may vary
slightly then hold steady.
Is the fuel pressure steady and does the fuel
pressure hold?
1. Start and idle the engine at normal operating
temperature.
14 2. The fuel pressure noted in the above step should
drop by the indicated value.
Does the fuel pressure drop by the indicated value?
Replace the MAP sensor.
15
Is the action complete?
1. Using the scan tool, clear the Diagnostic Trouble
Codes (DTCs).
2. Start the engine and idle at normal operating
temperature.
16
3. Operate the vehicle within the Conditions for
setting this DTC as specified in the supporting
text.
Does the scan tool indicate that this diagnostic has
run and passed?
Check if any additional DTCs are set.
17
Are any DTCs displayed that have not been
diagnosed?
DTC P0171 – Fuel Trim System Too Lean (Cont'd)
Action Value(s) Yes
–
Go to Step 16
5 Go to Step 11
–
Go to Step 16
–
Go to Step 16
380 KPa
(55 psi) Go to Step 14
Go to
21–69 KPa "Fuel Injector
(3–10 psi) 2alance Test"
–
Go to Step 16
–
Go to Step 17
Go to
applicable DTC
–
table
No
Go to Step 16
Go to Step 12
Go to Step 13
Go to Step 13
Go to
"Fuel System
Diagnosis"
Go to
"Fuel System
Diagnosis"
–
Go to Step 2
System OK
DAEWOO M-150 BL2