Isuzu 1999 RODEO Workshop Manual page 785

6E1–158 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
DTC P0135 – O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
Step
6 1. Allow the HO2S to cool for at least 10 minutes.
2. Using a Digital Voltmeter (DVM), measure the
resistance between the Bank 1 HO2S 1 ignition
feed and the Bank 1 HO2S 1 heater ground at the
Bank 1 HO2S 1 pigtail.
Is the HO2S heater resistance within the specified
values?
7 Repair the open Bank 1 HO2S 1 ignition feed circuit to
Bank 1 HO2S 1.
Is the action complete?
8 Repair the open Bank 1 HO2S 1 heater ground circuit
to Bank 1 HO2S 1.
Is the action complete?
9 1. Check for a poor connection at the Bank 1 HO2S 1
harness terminals.
2. If a poor connection is found, replace terminals.
Was a poor connection found?
10 Check for a poor Bank 1 HO2S 1 high or low circuit
terminal connection at the Bank 1 HO2S 1 harness
connector and replace terminal(s) if necessary.
Did any terminals require replacement?
11 1. Ignition OFF.
2. Disconnect the PCM and check the continuity of the
Bank 1 HO2S 1 signal circuit and the Bank 1 HO2S
1 low circuit.
3. If the Bank 1 HO2S 1 high circuit or HO2S low circuit
measures over 5 W, repair open or poor connection
as necessary.
Was a problem found?
12 Check for a poor Bank 1 HO2S 1 low circuit terminal
connection at the PCM and replace the terminal if
necessary.
Did the terminal require replacement?
13 Check for a poor Bank 1 HO2S 1 high circuit terminal
connection at the PCM and replace the terminal if
necessary.
Did the terminal require replacement?
14 Replace the Bank 1 HO2S 1.
Is the action complete?
15 Locate and repair the short to ground in Bank 1 HO2S 1
ignition feed circuit and replace the fault fuse.
Is the action complete?
(Cont'd)
Action Value(s) Yes
3–6 ohms Go to Step 9
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
— Verify repair
No
Go to Step 10
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—
Go to Step 10
Go to Step 11
Go to Step 12
Go to Step 13
Go to Step 14
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