Daewoo MATIZ Service Manual page 209

Step
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. Disconnect the vacuum hose from the fuel
pressure regulator and inspect the hose for the
presence of fuel.
13
2. If fuel is presence in the vacuum hose, replace
the fuel pressure regulator.
Is the repair complete?
1. Turn the ignition ON.
2. Slowly press the acceleration pedal.
Does the Throttle Position (TP) sensor display
14
increase steady and evenly from its minimum
voltage at closed throttle to its maximum voltage at
Wide-Open Throttle (WOT).
1. Perform the Fuel System Diagnosis.
15 2. If the table isolate a problem, repair as needed.
Is the repair complete?
1. Perform the Evaporative Emission (EVAP)
Control System Diagnosis.
16
2. If the table isolate a problem, repair as needed.
Is the repair complete?
1. Perform the Fuel Injector balance Test.
17 2. If the table isolate a problem, repair as needed.
Is the repair complete?
1. Remove the Oxygen Sensor (O2S)
2. Visually/physically inspect the O2S for silicone
contamination.
3. Note: this will be indicated by a powdery white
18 deposit on the portion of the O2S exposed to the
exhaust stream.
4. If contamination is present on the O2S, find the
source and repair as needed.
Is the repair complete?
1. Check the TP sensor mounting screws.
2. If they are too loose or missing tighten or replace
them as needed.
19
3. If the screws are OK, replace the TP sensor.
Is the repair complete?
1. Turn the ignition OFF.
20 2. Replace the MAP sensor.
Is the repair complete?
DAEWOO M-150 BL2
DTC P0172 – Fuel Trim System Too Rich (Cont'd)
Action
ENGINE CONTROLS 1F – 111
Value(s) Yes
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Go to Step 21
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Go to Step 21
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Go to Step 15
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Go to Step 21
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Go to Step 21
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Go to Step 21
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Go to Step 21
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Go to Step 21
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Go to Step 21
No
Go to Step 13
Go to Step 14
Go to Step 19
Go to Step 16
Go to Step 17
Go to Step 18
Go to
"Diagnostic
Aids"
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