Chrysler Pacifica. Manual — part 160

Symptom:

*BLOWER SPEED DOES NOT CORRESPOND WITH CONTROL
SETTING - MTC

POSSIBLE CAUSES

BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO GROUND

BLOWER MOTOR DRIVER CIRCUIT(S) SHORTED TO VOLTAGE

BLOWER MOTOR DRIVER CIRCUITS SHORTED TOGETHER

A/C HEATER CONTROL

BLOWER MOTOR DRIVER CIRCUIT(S) OPEN

BLOWER MOTOR RESISTOR BLOCK

TEST

ACTION

APPLICABILITY

1

Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Measure the resistance between ground and each of the Blower Motor Driver circuits.
Is the resistance below 10K ohms on any of the circuits?

All

Yes

→ Repair all Blower Motor Driver circuits with a resistance below

10K ohms for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 2

2

Turn the ignition off.
Ensure that the Blower Motor Resistor Block C1 harness connector is connected to
the Blower Motor Resistor Block.
Disconnect the A/C Heater Control C2 harness connector.
Turn the ignition on.
Press the A/C Heater Control’s power switch on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe each of the Blower Motor
Driver circuits (cavities 2, 3, 9, 10).
Does the test light illuminate brightly on each circuit?

All

Yes

→ Go To 3

No

→ Go To 5

3

Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Turn the ignition on.
Press the A/C Heater Control’s power switch on.
Measure the voltage of each of the Blower Motor Driver circuits (cavities 2, 3, 9, 10)
in the A/C Heater Control C2 harness connector.
Is there any voltage present?

All

Yes

→ Repair all Blower Motor Driver circuits with voltage present for a

short to voltage.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 4

637

HEATING & A/C

TEST

ACTION

APPLICABILITY

4

Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Measure the resistance between the Blower Motor Low Driver circuit and the Blower
Motor M1 Driver circuit, the Blower Motor M2 Driver circuit, and the Blower Motor
High Driver circuit.
Measure the resistance between the Blower Motor M1 Driver circuit and the Blower
Motor M2 Driver Circuit, and the Blower Motor High Driver circuit.
Measure the resistance between the Blower Motor M2 Driver circuit and the Blower
Motor High Driver circuit.
Is the resistance below 10K ohms between any of the circuits?

All

Yes

→ Repair all circuits with a resistance below 10K ohms for a short

together.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the A/C Heater Control in accordance with the Service

Information.
Perform BODY VERIFICATION TEST - VER 1.

5

Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Disconnect the Blower Motor Resistor Block C1 harness connector.
Measure the resistance of each Blower Motor Driver circuit between the Blower
Motor Resistor Block C1 harness connector and the A/C Heater Control C2 harness
connector.
Is the resistance below 5.0 ohms on each of the circuits?

All

Yes

→ Replace the Blower Motor Resistor Block in accordance with the

Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair all Blower Motor Driver circuits with a resistance above

5.0 ohms for an open.
Perform BODY VERIFICATION TEST - VER 1.

638

HEATING & A/C

*BLOWER SPEED DOES NOT CORRESPOND WITH CONTROL SETTING
- MTC —

Continued

Symptom:

*FRONT BLOWER MOTOR INOPERATIVE - ATC

POSSIBLE CAUSES

INTEGRATED POWER MODULE (IPM) DTC(S) PRESENT

INTERMITTENT CONDITION

FUSED FRONT BLOWER RELAY OUTPUT CIRCUIT SHORTED TO GROUND

FRONT BLOWER MOTOR

FRONT BLOWER POWER MODULE

GROUND CIRCUIT OPEN

FRONT BLOWER MOTOR CONTROL CIRCUIT SHORTED TO VOLTAGE

FRONT BLOWER MOTOR CONTROL CIRCUIT OPEN

FRONT BLOWER POWER MODULE

AUTOMATIC TEMPERATURE CONTROL (ATC)

FRONT BLOWER MOTOR

FRONT BLOWER POWER MODULE

INTEGRATED POWER MODULE (IPM) - OPEN CIRCUIT

INTEGRATED POWER MODULE (IPM) - OPEN CIRCUIT

FRONT BLOWER RELAY

INTEGRATED POWER MODULE (IPM) - OPEN CIRCUIT

FUSED FRONT BLOWER RELAY OUTPUT CIRCUIT OPEN

TEST

ACTION

APPLICABILITY

1

NOTE: Verify that the vehicle’s odometer displays more than 3 miles. If not,
drive the vehicle until the odometer displays more than 3 miles and then
recheck blower motor operation. If still inoperative, proceed as follows:
Turn the ignition on.
With the DRBIII

t, read IPM DTCs.

Does the DRBIII

t display any DTCs?

All

Yes

→ For Integrated Power Module (IPM) DTCs related to the front

blower or rear fan relay circuits, refer to the Heating & A/C
category. For all other IPM DTCs, refer to the appropriate
category for the related symptom(s).
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 2

2

Turn the ignition off.
Remove and inspect IPM Fuse #42 (Front Blower Fuse).
Is the fuse open?

All

Yes

→ Go To 3

No

→ Go To 6

639

HEATING & A/C

TEST

ACTION

APPLICABILITY

3

Replace IPM Fuse #42 (Front Blower Fuse).
Turn the ignition on.
Operate the Front Blower Motor in all speeds.
Start the engine and operate the ATC system in all modes and speeds.
Does the Front Blower Motor operate properly without blowing the fuse?

All

Yes

→ Refer to the wiring diagrams located in the service information to

help isolate a possible intermittent short to ground condition.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 4

4

Turn the ignition off.
Disconnect the Front Blower Power Module C1 harness connector.
Measure the resistance between ground and the Fused Front Blower Relay Output
circuit.
Is the resistance below 10K ohms?

All

Yes

→ Repair the Fused Front Blower Relay Output circuit for a short to

ground. Replace IPM Fuse #42 (Front Blower Fuse).
Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 5

5

Turn the ignition off.
Replace IPM Fuse #42 (Front Blower Fuse).
Disconnect the Front Blower Power Module C1 harness connector.
Disconnect the Front Blower Power Module C2 harness connector.
Connect a jumper wire between the Fused Front Blower Relay Output circuit in the
Front Blower Power Module C1 harness connector and the Blower Motor Supply
circuit in the Front Blower Power Module C2 harness connector.
Connect a jumper wire between the Ground circuit in the Front Blower Power
Module C1 harness connector and the Blower Motor Ground circuit in the Front
Blower Power Module C2 harness connector.
Turn the ignition on.
Does the Front Blower Motor operate at full speed without blowing the fuse?

All

Yes

→ Replace the Front Blower Power Module in accordance with the

Service Information. Replace IPM Fuse #42 (Front Blower Fuse).
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the Front Blower Motor in accordance with the Service

Information. Replace IPM Fuse #42 (Front Blower Fuse).
Perform BODY VERIFICATION TEST - VER 1.

6

Ensure IPM Fuse #42 (Front Blower Fuse) is installed.
Disconnect the Front Blower Power Module C1 harness connector.
Turn the ignition on.
NOTE: The test light must illuminate brightly. Compare the brightness to
that of a direct connection to the battery.
Using a 12-volt test light connected to ground, back probe the Fused Front Blower
Relay Output circuit in the Front Blower Power Module C1 harness connector.
Does the test light illuminate brightly?

All

Yes

→ Go To 7

No

→ Go To 13

640

HEATING & A/C

*FRONT BLOWER MOTOR INOPERATIVE - ATC —

Continued