Isuzu 2000 Trooper Workshop Manual page 1263

6E–394
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS
Diagnostic Aids
A malfunction in the HO2S heater ignition feed or ground
circuit may cause a DTC P1133 to set. Check HO2S
heater circuitry for intermittent faults or poor connections.
If connections and wiring are OK and DTC P1133
continues to set, replace the Bank 1 HO2S 1.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help to 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.
DTC P1133 – HO2S Insufficient Switching Bank 1 Sensor 1
Step
1 Was the "On-Board Diagnostic (OBD) System Check"
performed?
2 IMPORTANT: If any DTCs are set (except P1153 or
P1154) refer to those DTCs before proceeding with this
diagnostic chart.
1. Engine idling at operating temperature.
2. Operating the vehicle within parameters specified
under "Conditions for Setting the DTC" criteria
included in Diagnostic Support.
3. Using a Tech 2, monitor "DTC" info for DTC P1133
until the DTC P1133 test runs.
4. Note the test result.
Does the Tech 2 indicate DTC P1133 failed this
ignition?
3 Did the Tech 2 also indicate that the P1153 or P1154
tests failed?
4 Check for leaks at the exhaust pipe joints.
Are the joints leaking?
5 Tighten the bolt/nuts at the leaking joints.
Is your action complete?
6 Check for gaskets that are damaged or improperly
installed.
Are there damaged or misaligned gaskets?
7 1. Replace the damaged gaskets.
2. Align the connections.
3. Tighten the connections.
Is your action complete?
8 Check for loose exhaust flange connections.
Are the flange connections loose?
9 Tighten the stud nuts or bolts to specifications.
Is your action complete?
10 Check for burned or corroded exhaust pipes.
Are the exhaust pipes burned or corroded?
Action
3. A condition that affects other heated oxygen sensors
indicates probable contamination. To avoid
damaging the replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
5. This step checks for conditions which may cause the
heated oxygen sensor to appear faulty. Correct any
of the described conditions if present.
11.To avoid damaging replacement sensors, correct the
condition which caused the contamination before
replacing the affected sensors.
Value(s)
— Go to Step 2
— Go to Step 3
— Go to Step 20
— Go to Step 5
— Go to Step 2
— Go to Step 7
Go to Step 2
—
Go to Step 9
—
— Go to Step 2
— Go to Step 11
Yes No
Go to OBD
System
Check
Refer to
Diagnostic
Aids
Go to Step 4
Go to Step 6
—
Go to Step 8
—
Go to Step 10
—
Go to Step 12