Dtc P0172 Fuel Trim System Too Rich - Daewoo CIELO EURO III Manual

harness related to the engine harness. A change in the
display will indicate the location of the fault.
If a DTC P1404 is also set, check the 5 volt reference
circuits for a short to voltage.
Check for a restricted exhaust system.
A shorted 5 volt reference circuit may cause a DTC
P0172 to set. Check the 5 volt reference sensors for ab-
normal readings.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Table.
1. The On-Board Diagnostic (EOBD) System Check
prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This
Step
Perform an On-Board Diagnostic (EOBD) System
Check.
1
Is the system check complete?
Install the scan tool.
2
Are any component related Diagnostic Trouble
Codes (DTCs) set?
With the engine running, operate the vehicle while in
Closed Loop
3
Is the Fuel Trim Index above the specified value?
1. Turn the ignition switch ON, with the engine OFF.
2. Review the Freeze Frame data and note the
parameters.
3. Operate the vehicle within the Freeze Frame
4
conditions and Conditions for Setting The DTC as
noted.
Is the Fuel Trim Index above the specified value
while operating under the specified conditions?
1. Visually and physically check the air cleaner filter
for excessive dirt or being plugged.
5
2. Repair as necessary.
Does the air cleaner filter require replacement?
1. Visually and physically check the air intake
system for being collapsed or restricted.
6
2. Repair as necessary.
Does the air intake system require repair?
Inspect the throttle body inlet for damage or foreign
objects which may partially block the airflow and cor-
rect any problem found.
7
Does the inspection of the throttle body reveal a
condition requiring a repair or replacement?
DAEWOO T-154 BL2,3

DTC P0172 Fuel Trim System Too Rich

Action
ENGINE CONTROLS 1F – 196
creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.
5. A clogged air cleaner filter element restricts the air-
flow coming into the engine. This step checks the
condition of the air cleaner filter.
17. A leaky injector can cause a rich condition and set
DTC P0172. Refer to "Fuel injector Balance Test" in
this section.
19. A loose TP sensor may not set a TP sensor related
DTC, but may cause the system to become rich by a
higher-than-actual TP reading.
22. If no faults have been found at this point and no
additional DTCs were set, refer to "Diagnostic Aids"
for additional checks and information.
Value
–
Go to Step 2
– Go to applicable
DTC table
–20% Go to Step 4
–20% Go to Step 21
–
Go to Step 21
–
Go to Step 21
–
Go to Step 21
Yes No
Go to "On-
Board Diag-
nostic System
Check"
Go to Step 3
Go to Step 5
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8