Isuzu 1999 RODEO Workshop Manual page 781

6E1–154 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
signal line shorted to ground or signal lines shorted
together. Disconnect the HO2S and connect a test light
between the HO2S ignition feed and heater ground
circuits. If the test light does not light for 2 seconds
when the ignition is turned on, repair the open ignition
feed or sensor ground circuit as necessary. If the test
light lights and the HO2S signal and low circuits are
OK, replace the HO2S.
f Intermittent test – With the ignition ON monitor the
HO2S signal voltage while moving the wiring harness
DTC P0134 – O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 1. Install the Tech 2.
2. Run the engine at operating temperature.
3. Operate the engine above 1200 RPM for three
minutes.
Does the Tech 2 indicate Bank 1 HO2S 1 voltage
varying outside the specified values?
3 1. Ignition ON, engine OFF review and record Tech 2
Failure Records data and note parameters.
2. Operate the vehicle within Failure Records
conditions as noted.
3. Using a Tech 2, monitor "Diagnostic Trouble Code"
info for Diagnostic Trouble Code P0134 until the
Diagnostic Trouble Code P0134 test runs.
4. Note the test result.
Does the Tech 2 indicate Diagnostic Trouble Code
P0134 failed this ignition?
4 Check for a damaged harness.
Was a problem found?
5 Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the Bank 1 HO2S 1 harness
connector and replace terminal(s) if necessary.
Did any terminals require replacement?
6 Check for poor Bank 1 HO2S 1 high and low circuit
terminal connections at the PCM and replace terminals
if necessary.
Did any terminals require replacement?
7 1. Ignition OFF.
2. With the PCM disconnected, check continuity of the
Bank 1 HO2S 1 high circuit.
3. If the Bank 1 HO2S 1 high circuit measures over 0.5
W, repair open or poor connection as necessary.
Was a Bank 1 HO2S 1 high circuit problem found and
corrected?
Action
and related connectors. If the fault is induced, the
HO2S signal voltage will change. This may help isolate
the location of the malfunction.
Reviewing the Failure Records vehicle mileage since the
diagnostic test last failed may help determine how often
the condition that caused the Diagnostic Trouble Code to
be set occurs. This may assist in diagnosing the
condition.
Value(s)
— Go to Step 2
400–500 mV Go to Step 3
— Go to Step 4
— Verify repair
— Verify repair
— Verify repair
— Verify repair
Yes No
Go to OBD
System
Check
Go to Step 4
Refer to
Diagnostic
Aids
Go to Step 5
Go to Step 6
Go to Step 7
Go to Step 8