Chrysler Voyager. Manual — part 213

TEST

ACTION

APPLICABILITY

15

Turn the ignition off.
Make sure that the Rear Blower Motor Relay is installed.
Remove IPM Fuse #12.
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, probe IPM Fuse #12 (power input
cavity).
Does the test light illuminate brightly?

All

Yes

→ Go To 16

No

→ Replace the Rear Blower Motor Relay in accordance with the

Service Information.
With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

16

Turn the ignition off.
Remove IPM Fuse #12.
Disconnect the IPM C8 harness connector.
Measure the resistance between IPM Fuse #12 (power output cavity) and cavity 7 of
the IPM C8 connector (IPM side).
Is the resistance below 5 ohms?

All

Yes

→ Repair the Fused Rear Blower Motor Relay Output circuit for an

open.
With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the IPM in accordance with the Service Information.

With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

279

AUTOMATIC TEMPERATURE CONTROL

*REAR BLOWER MOTOR INOPERATIVE —

Continued

Symptom:

*REAR BLOWER RUNS AT ONLY ONE SPEED

POSSIBLE CAUSES

REAR BLOWER MOTOR CONTROL CIRCUIT SHORTED TO GROUND

AUTOMATIC TEMPERATURE CONTROL MODULE

REAR BLOWER MOTOR POWER MODULE

TEST

ACTION

APPLICABILITY

1

Turn the ignition off.
Disconnect the Rear Blower Motor Power Module C1 harness connector.
Disconnect the Automatic Temperature Control Module C2 harness connector.
Measure the resistance between ground and the Rear Blower Motor Control circuit.
Is the resistance below 10K ohms?

All

Yes

→ Repair the Rear Blower Motor Control circuit for a short to

ground.
With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

No

→ Go To 2

280

AUTOMATIC TEMPERATURE CONTROL

TEST

ACTION

APPLICABILITY

2

Turn the ignition off.
Reconnect all previously disconnected components.
Connect the DRBIII

t X10 Scope Probe CH7061 to Channel 1 on the DRBIIIt.

Select the following from the DRBIII

t menu: PEP Module Tools; Lab Scope; Live

Data; and Lab Scope.
Press F2 and then press Enter.
Using the left/right arrow keys, set the time to 10ms/Div.
Press F2.
Using the up/down arrow keys, set the voltage range to +20.0v.
Press Enter to move the cursor to Probe.
Using the up/down arrow keys, set the Probe to X10.
Press F2.
Start the engine.
Press the ATC Power switch on.
Set the Rear System switch on the ATC module to the Rear Control position.
Using the X10 Scope Probe, back probe the Rear Blower Motor Control circuit in the
Automatic Temperature Control Module C2 harness connector.
NOTE: The Rear Blower Motor Power Module provides a 10.0 volt signal to
the ATC Module over the Rear Blower Motor Control circuit. The ATC
Module provides a variable duty cycle ground to the 10.0 volt signal based
on input from the Rear Blower switch.
NOTE: When the Rear Blower switch is set to LO speed, the ATC Module
provides a short duty cycle (less time grounding the signal voltage).
NOTE: As higher blower speeds are requested, the ATC Module increases
the duty cycle (more time grounding the signal voltage).
NOTE: When the Rear Blower switch reaches HI speed, the duty cycle
increases to where the signal pattern is almost a flat line (with brief voltage
spikes).
Set the blower switch on the Rear ATC Control panel to LO speed then slowly move
it to HI speed while observing the DRBIII

t display.

The voltage on the scope patten should cycle from approximately 2.0 volts (duty cycle
on) to 10.0 volts (duty cycle off) for all blower speeds.
The duty cycle pattern should change smoothly as the Rear Blower switch is turned
from LO to HI.
The duty cycle on time should change from approximately 8 ms at LO speed, to 15 ms
at medium speed, and to 25 ms at HI speed.
Does the DRBIII

t display the voltage range and duty cycle as described above?

All

Yes

→ Replace the Rear Blower Motor Power Module in accordance with

the Service Information.
With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

No

→ Replace the Automatic Temperature Control Module in accor-

dance with the Service Information.
With the DRBIII

t, reset the ATC after repair is complete.

Perform BODY VERIFICATION TEST - VER 1.

281

AUTOMATIC TEMPERATURE CONTROL

*REAR BLOWER RUNS AT ONLY ONE SPEED —

Continued

Symptom List:

A. CABIN HEATER PRE-TEST
CABIN HEATER CONTROL CIRCUIT OPEN (STORED)
CABIN

HEATER

CONTROL

CIRCUIT

SHORT

TO

BATTERY

(STORED)

Test Note:

All symptoms listed above are diagnosed using the same tests.

The title for the tests will be A. CABIN HEATER PRE-TEST.

When Monitored and Set Condition:

CABIN HEATER CONTROL CIRCUIT OPEN (STORED)

When Monitored:

When the DCHA system is off.

Set Condition:

The DCHA Low Side Driver inside the FCM expects to see a system

voltage of 13.8 volts through the DCHA relay coil when the DCHA system is off. This DTC
will set if the FCM sees a voltage below 3.5 volts on the Cabin Heater Assist Control circuit
during this time.

CABIN HEATER CONTROL CIRCUIT SHORT TO BATTERY (STORED)

When Monitored:

During DCHA activation and operation.

Set Condition:

This DTC will set if the FCM sees between 5.0 and 15.0 volts on the Cabin

Heater Assist Control circuit.

POSSIBLE CAUSES

NO RESPONSE FROM CABIN HEATER MODULE

DTC(S) PRESENT

CABIN HEATER INOPERABLE FROM A/C - HEATER MODULE (MTC)

CABIN HEATER INOPERABLE FROM AUTO TEMP CONTROL (ATC)

STORED DCHA DTC(S) TEST COMPLETE

282

CABIN HEATER