Isuzu 1999 RODEO Workshop Manual page 873

6E1–246 RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
Step
1 Was the Powertrain "On–Board Diagnostic (OBD)
System Check" performed?
2 1. Turn the ignition switch ON, with the engine OFF.
2. Review and record Tech 2 Failure Records data,
then clear the DTC's.
3. Operate the vehicle within the Failure Records
conditions as noted.
4. Using the Tech 2, monitor "DTC" info for DTC
P0406.
Does the Tech 2 indicate DTC P0406 "Ran and
Passed?"
3 1. Ignition OFF.
2. Disconnect the Linear Exhaust Gas Recirculation
(EGR) Valve from the wiring harness.
3. Ignition ON, Engine OFF.
4. Using a Digital Voltmeter (DVM), check for voltage
on the ignition feed circuit at the Linear Exhaust Gas
Recirculation
connector.
Does the DVM read the following value?
4 Check the ignition feed circuit, between the EGR
sensor and the "Engine IG." fuse, for the following
conditions:
f
An open circuit
f
A short to ground
Was the problem found?
5 Using a DVM, check the resistance of the EGR
solenoid.
Does the DVM read the following value?
6 Check the EGR solenoid valve Low circuit, between the
EGR sensor and the PCM, for the following conditions:
f
An open circuit
f
A short to ground
f
A short to voltage
Was the problem found?
7 1. Ignition OFF.
2. Disconnect the Linear Gas Recirculation (EGR)
Valve from the wiring harness.
3. Ignition ON, Engine OFF.
4. Observe the EGR value on the Tech 2.
Does the Tech 2 display the following value(s)?
8 Check the EGR position feedback circuit, between the
EGR sensor and the PCM, for the following conditions:
f
An open circuit
f
A short to ground
f
A short to voltage
Was the problem found?
DTC P0406 EGR Sensor Circuit High
Action
(EGR) Valve wiring
Value(s)
—
—
harness
12 Volts
—
less then 5 W
—
0 Volts 0%
—
Yes No
Go to
Powertrain
OBD System
Go to Step 2 Check
Refer to
Diagnostic
Aids Go to Step 3
Go to Step 6 Go to Step 4
Verify repair —
Go to Step 14
Go to Step 6
Go to Step 15
Verify repair
Go to Step 9 Go to Step 8
Go to Step 15
Verify repair