Isuzu Rodeo UE. Manual - part 243

6E1–343

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P1546 A/C COMPRESSOR CLUTCH

OUTPUT CIRCUIT MALFUNCTION

D06RX037

Circuit Description

The Powertrain Control Module (PCM) controls the A/C
Compressor Clutch Solenoid through the use of a relay
and a control (ground) circuit.  If the PCM commands the
A/C Compressor Clutch Solenoid ON but the voltage
remains High (12 volts) or, if the PCM commands the A/C
Compressor Clutch Solenoid OFF but the voltage
remains Low (0 volts), then DTC P1546 will set. DTC
P1546 is a type D code.

Conditions for Setting the DTC

f

Ignition voltage is greater than 10 volts.

f

Engine run time is greater than 32 seconds.

The above mentioned conditions are met and one of the
following two conditions are met for 25 seconds within a
50 second test sample.

f

PCM senses voltage is High with the A/C Compressor
Clutch Solenoid commanded ON.

OR

f

PCM senses voltage is Low with the A/C Compressor
Clutch Solenoid commanded OFF.

Action Taken When the DTC Sets

f

The PCM will not illuminate the Malfunction Indicator
Lamp (MIL).

f

The PCM will store the conditions that were present
when the DTC was set as Freeze Frame and in Failure
Records.

Conditions for Clearing the DTC

f

A history DTC will clear after 40 consecutive trips
without a reported failure.

f

The DTC can be cleared using the Scan Tool’s ”Clear
Info” function.

Diagnostic Aids

f

Poor connections, or a damaged harness – Inspect the
harness connectors for: backed–out terminals,
improper mating or damaged terminals. Also check for
open circuits, shorts to ground, and shorts to voltage.

6E1–344

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P1546  A/C Compressor Clutch Output Circuit Malfunction

 

Step

Action

Value(s)

Yes

No

1

Was the ”On–Board Diagnostic (OBD) System Check”
performed?

—

Go to Step 2 

Go to OBD

System

Check 

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?”

—

Refer to

Diagnostic

Aids 

Go to Step 3 

3

1. Ignition OFF.
2. Remove the A/C Compressor Clutch 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
Relay connector.

Does the DVM read the following value?

12 Volts

Go to Step 5 

Go to Step 4 

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?

—

Verify repair

—

5

1. Ignition OFF.
2. Disconnect the Powertrain Control 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?

—

Verify repair

Go to Step 6 

6

1. Reinstall the A/C Compressor Clutch Relay.
2. Using a fused jumper, ground the A/C Compressor

Clutch Relay control circuit at the PCM  connector.

3. Ignition ON, Engine OFF.

Does the A/C Compressor turn ON?

—

Go to Step 9 

Go to Step 7 

7

1. Ignition OFF.
2. Check the A/C Compressor Clutch circuit between

the A/C Compressor Clutch Relay and A/C
Compressor Clutch for the following conditions:

f

A short to ground

f

An open circuit

f

A short to voltage

Was the problem found?

—

Verify repair

Go to Step 8 

6E1–345

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P1546  A/C Compressor Clutch Output Circuit Malfunction

  (Cont'd)

Step

No

Yes

Value(s)

Action

8

Replace the A/C Compressor Clutch Relay.

Is the action complete?

—

Verify repair

—

9

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to On–Vehicle Service in
Powertrain Control Module and Sensors for
procedures. 

And also refer to latest Service Bulletin.
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Verify repair.

—

—

—

6E1–346

RODEO X22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Diagnostic Trouble Code (DTC) P1625 PCM Unexpected Reset

014RX002

Circuit Description

The powertrain control module (PCM) monitors
unexpected PCM reset. This will not turn on MIL light on,
only records code DTC P1625.

Conditions for Setting the DTC

f

Clock or COP (Computer Operating Properly) reset.

Action Taken When the DTC Sets

f

The PCM will not illuminate the malfunction indicator
lamp (MIL).

f

The PCM will store conditions which were present
when the DTC was set as Failure Records only. This
information will not be stored as Freeze Frame data.

Conditions for Clearing the DTC

f

The PCM will turn the MIL “OFF” on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.

f

A history DTC P1625 will clear after 40 consecutive
warm-up cycles have occurred without a fault.

f

DTC P1625 can be cleared by using the Tech 2 “Clear
Info” function or by disconnecting the PCM battery
feed.

Diagnostic Aids

Check for the following conditions:

f

P1625 alone stored does not need diagnosis. Clear
DTC code.

NOTE: DTC  P1625 is a DTC to record a PCM reset
history. If DTC P1625 is not reset and no engine
abnormality is found after clearance of DTC, it  is not
necessary to do any farther processing.