Chrysler Pacifica. Manual — part 152

Symptom:

REAR BOOSTER FAN RELAY OPEN - ATC

When Monitored and Set Condition:

REAR BOOSTER FAN RELAY OPEN - ATC

When Monitored:

With the ignition off.

Set Condition:

If the Integrated Power Module (IPM) detects an open on the Rear Booster

Fan Relay Control circuit.

POSSIBLE CAUSES

B+ CIRCUIT OPEN

REAR BOOSTER FAN RELAY

INTEGRATED POWER MODULE (IPM)

TEST

ACTION

APPLICABILITY

1

Turn the ignition off.
Remove the Rear Booster Fan Relay from the IPM.
Using a 12-volt test light connected to ground, probe cavity 85 of the rear booster fan
relay connector.
Is the test light illuminated?

All

Yes

→ Go To 2

No

→ Check the B+ feed to the IPM for an open. If OK, replace the IPM

in accordance with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

2

Turn the ignition off.
Install a substitute relay in place of the existing Rear Booster Fan Relay.
Turn the ignition on.
With the DRBIII

t, erase DTCs.

Turn the ignition off.
With the DRBIII

t, read IPM DTCs.

Does the DRBIII

t display: REAR BOOSTER FAN RELAY OPEN?

All

Yes

→ Replace the Integrated Power Module (IPM) in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the original Rear Booster Fan Relay in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

605

HEATING & A/C

Symptom:

REAR BOOSTER FAN RELAY SHORT TO BATT - ATC

When Monitored and Set Condition:

REAR BOOSTER FAN RELAY SHORT TO BATT - ATC

When Monitored:

With the ignition on.

Set Condition:

If the Integrated Power Module (IPM) detects excessive current when

attempting to close the Rear Booster Fan Relay.

POSSIBLE CAUSES

REAR BOOSTER FAN RELAY

INTEGRATED POWER MODULE (IPM)

TEST

ACTION

APPLICABILITY

1

Turn the ignition off.
Install a substitute relay in place of the existing Rear Booster Fan Relay.
Turn the ignition on.
With the DRBIII

t, erase DTCs.

Turn the ignition off, wait 30 seconds, then turn the ignition on.
With the DRBIII

t, read IPM DTCs.

Does the DRBIII

t display: REAR BOOSTER FAN RELAY SHORT TO BATT

All

Yes

→ Replace the Integrated Power Module (IPM) in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the original Rear Booster Fan Relay in accordance with

the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

606

HEATING & A/C

Symptom:

REAR FAN POT OPEN (ACTIVE) - ATC

When Monitored and Set Condition:

REAR FAN POT OPEN (ACTIVE) - ATC

When Monitored:

With the ignition on and the IOD fuse installed.

Set Condition:

This DTC will set if the Rear Fan Sense input is above 253 A/D counts (4.9

volts).

POSSIBLE CAUSES

REAR FAN SENSE SUPPLY CIRCUIT SHORTED TO VOLTAGE

AUTOMATIC TEMPERATURE CONTROL (ATC)

REAR FAN SENSE CIRCUIT SHORTED TO VOLTAGE

AUTOMATIC TEMPERATURE CONTROL (ATC)

REAR FAN SENSE CIRCUIT OPEN

AUTOMATIC TEMPERATURE CONTROL (ATC)

REAR FAN SENSE SUPPLY CIRCUIT SHORTED TO REAR FAN SENSE CIRCUIT

REAR FAN SENSE RETURN CIRCUIT OPEN

REAR BOOSTER FAN REAR CONTROL SWITCH

AUTOMATIC TEMPERATURE CONTROL (ATC)

TEST

ACTION

APPLICABILITY

1

Turn the ignition off.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Turn the ignition on.
Measure the voltage of the Rear Fan Sense Supply circuit.
Is the voltage above 5.3 volts?

All

Yes

→ Go To 2

No

→ Go To 3

2

Turn the ignition off.
Disconnect the ATC C1 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Turn the ignition on.
Measure the voltage between the Rear Fan Sense Supply circuit and ground.
Is the voltage above 0.2 volts?

All

Yes

→ Repair the Rear Fan Sense Supply circuit for a short to voltage.

Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the Automatic Temperature Control (ATC) in accordance

with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

607

HEATING & A/C

TEST

ACTION

APPLICABILITY

3

Turn the ignition off.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Turn the ignition on.
Measure the voltage of the Rear Fan Sense circuit.
What voltage is present?

All

Above 5.1 Volts

Go To

4

Below 0.25 Volts

Go To

5

Between 0.25 & 5.1 Volts

Go To

6

4

Turn the ignition off.
Disconnect the ATC C1 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Turn the ignition on.
Measure the voltage between the Rear Fan Sense circuit and ground.
Is the voltage above 0.2 volts?

All

Yes

→ Repair the Rear Fan Sense circuit for a short to voltage.

Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the Automatic Temperature Control (ATC) in accordance

with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

5

Turn the ignition off.
Disconnect the ATC C1 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Measure the resistance of the Rear Fan Sense circuit between the ATC C1 harness
connector and the Rear Booster Fan Rear Control Switch harness connector.
Is the resistance below 5.0 ohms?

All

Yes

→ Replace the Automatic Temperature Control (ATC) in accordance

with the Service Information.
Perform BODY VERIFICATION TEST - VER 1.

No

→ Repair the Rear Fan Sense circuit for an open.

Perform BODY VERIFICATION TEST - VER 1.

6

Turn the ignition off.
Disconnect the ATC C1 harness connector.
Disconnect the Rear Booster Fan Rear Control Switch harness connector.
Measure the resistance between the Rear Fan Sense Supply circuit and the Rear Fan
Sense circuit.
Is the resistance above 100K ohms?

All

Yes

→ Go To 7

No

→ Repair the Rear Fan Sense Supply circuit for a short to the Rear

Fan Sense circuit.
Perform BODY VERIFICATION TEST - VER 1.

608

HEATING & A/C

REAR FAN POT OPEN (ACTIVE) - ATC —

Continued