Isuzu 1999 RODEO Workshop Manual page 804

Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 Are any Diagnostic Trouble Codes set other than
P0172?
3 1. Start the engine and operate the vehicle in "Closed
Loop".
2. Observe "BANK 1 L.T. FUEL TRIM" display on the
Tech 2.
Are the displayed values more negative than the
specified values?
4 1. Review and record the Tech 2 Failure Records data.
2. Clear the Diagnostic Trouble Code P0172 and
operate the vehicle to duplicate the Failure Records
conditions.
3. Monitor the Tech 2 "Diagnostic Trouble Code" info
for Diagnostic Trouble Code P0172 while operating
the vehicle to duplicate the Failure Records
conditions.
4. Continue operating the vehicle until the Diagnostic
Trouble Code P0172 test runs and note test result.
Does the Tech 2 indicate Diagnostic Trouble Code
P0172 failed this ignition?
5 Visually and physically inspect the air filter element and
replace it if necessary.
Did the air filter require replacement?
6 Visually and physically inspect the air intake duct for
collapse or restriction and repair if necessary.
Did your inspection reveal a condition requiring repair?
7 Start the engine and note the idle quality.
Is a low or unsteady idle being experienced?
8 With the engine idling, observe the "IDLE AIR
CONTROL" display on the Tech 2.
Is the "IDLE AIR CONTROL" value below the specified
value?
9 1. Ignition OFF.
2. Physically inspect the throttle body bore, throttle
plate, and IAC passages for coking and foreign
objects.
3. If a problem was found, repair as necessary.
Did your inspection reveal a condition requiring repair?
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DTC P0172 – System Too Rich (Bank 1)
Action Value(s) Yes
— Go to Step 2
Go to the
applicable
DTC charts
and repair the
other DTCs
before
proceeding
with this
—
chart.
L.T. Fuel
Trim: –14% Go to Step 5
— Go to Step 5
— Verify repair
— Verify repair
— Go to Step 8
Below 100
Go to Step
counts
10
— Verify repair
6E1–177
No
Go to OBD
System
Check
Go to Step 3
Go to Step 4
The rich
condition is
not present. If
a driveability
symptom still
exists, refer
to Symptoms.
Go to Step 6
Go to Step 7
Go to Step
10
Go to Step 9
Go to Step
10