Isuzu 1999 RODEO Workshop Manual page 684

f Damaged harness – Inspect the wiring harness for
damage; shorts to ground, shorts to battery voltage,
and open circuits. If the harness appears to be OK,
observe the A/C clutch while moving connnectors and
wiring harnesses related to the A/C. A sudden clutch
malfunction will indicate the source of the intermittent.
A/C Clutch Diagnosis
This chart should be used for diagnosing the electrical
portion of the A/C compressor clutch circuit. A Tech 2 will
Step
1 Was the "On–Board Diagnostic (OBD) System Check"
performed?
2 1. Ignition ON, engine OFF.
2. Review and record Tech 2 Failure Records data,
then clear the DTCs.
3. Operate the vehicle within the Failure Records
conditions as noted.
4. Using the Tech 2, monitor "DTC" info for DTC
P1546.
Does the Tech 2 indicate DTC P1546 "Ran and
Passed"?
3 1. Ignition OFF.
2. Remove the A/C Compressor Relay from the
Underhood Electrical Center.
3. Ignition ON, engine OFF.
4. Using a Digital Voltmeter (DVM), check for voltage
on the Fused pins of the A/C Compressor Clutch
Relat connector.
Does the DVM read the following value?
4 Check the suspect circuit(s) between the A/C
Compressor Clutch Relay connector and the Fuse for
the following conditions:
f
A short to ground
f
An open circuit
f
A short to voltage
Was the problem found?
5 1. Ignition OFF.
2. Disconnect the Powertrain Controlm Module (PCM)
connectors from the PCM.
3. Check the A/C Compressor Clutch Relay control
circuit between the PCM and Underhood Electrical
Center for the following conditions:
f
A short to ground
f
An open circuit
f
A short to voltage
Was the problem found?
RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION
A/C Clutch Control Circuit Diagnosis
Action
be used in diagnosing the system. The Tech 2 has the
ability to read the A/C request input to the PCM. The Tech
2 can display when the PCM has commended the A/C
clutch ON. The Tech 2 should have the ability to override
the A/C request signal and energize the A/C compressor
relay.
Value(s)
Go to Step 2
—
Diagnostic
—
Go to Step 5
12 Volts
— Verify repair
— Verify repair
6E1–57
Yes No
Go to OBD
System
Check
Refer to
Aids
Go to Step 3
Go to Step 4
—
Go to Step 6