Dtc P0175 - Fuel Trim System Rich Bank 2 - Isuzu Trooper 1999 Workshop Manual

6E–244
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
f Barometric pressure is greater than 72.5 kPa.
f Mass air flow is between 2 g/second and 200 g/second.
f Ignition voltage is above 9.5 volts.
f Fuel system is in "closed loop."
f Canister purge duty cycle is greater than 15%, if "ON."
Action Taken When the DTC Sets
f The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
failure is detected.
f The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
Conditions for Clearing the MIL/DTC
f The PCM will turn the MIL "OFF" on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
f A history DTC P0175 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
f DTC P0175 can be cleared by using the Tech 2 "Clear
Info" function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check for the following conditions:
f Poor connection at PCM – Inspect harness connectors
for backed -out terminals, improper mating, broken
Step
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
2 Are any DTCs set other than P0172 and P0175?
3 1. Start the engine and operate the vehicle in "closed
loop."
2. Observe the "BANK 2 L.T. FUEL TRIM" display on
the Tech 2.
Is the displayed value more negative than the specified
value?
DTC P0175 – Fuel Trim System Rich Bank 2
Action
locks, improperly formed or damaged terminals, and
poor terminal-to-wire connection.
f Damaged harness – Inspect the wiring harness for
damage. If the harness appears to be OK, observe the
Bank 2 HO2S 1 display on the Tech 2 while moving
connectors and wiring harnesses related to the engine
harness. A change in the display will indicate the
location of the fault.
Reviewing the Failure Records Vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the DTC to be set occurs. This
may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the
Diagnostic Chart.
2. DTCs other than P0172 and P0175 may indicate a
condition present which may cause a lean condition.
If this is the case, repairing the condition which
caused the other DTC will most likely correct the
DTC P0172/P0175.
4. If the DTC P0175 test passes while the Failure
Records conditions are being duplicated, the rich
condition is intermittent. Refer to Diagnostic Aids or
Symptoms for additional information on diagnosing
intermittent problems.
Value(s)
— Go to Step 2
Go to the
applicable
DTC charts
and repair the
other DTCs
proceeding
—
L.T. Fuel
Trim: –15%
(auto. trans.)
OR –12%
Go to Step 5
(man. trans.)
Yes No
Go to OBD
System
Check
before
with this
chart. Go to Step 3
Go to Step 4