| 1 |
CHECK THE SYSTEM AIRFLOW
- Key ON engine running (KOER).
- Adjust the blower motor speed to maximum. Check for correct airflow in each function selector switch position at engine idle and during engine acceleration.
- Is there airflow only from the defroster outlets under all conditions?
|
Yes |
Go to next step. |
| No |
Go to step 8. |
| 2 |
CHECK THE VACUUM SUPPLY LINE FOR OBSTRUCTIONS
NOTE:
- The two vacuum lines to the vacuum reservoir tank are not interchangeable.
- Disconnect the vacuum lines from the vacuum reservoir tank.
- Connect the vacuum pump SST
to the vacuum supply line and try to pull a vacuum. If the pump can pull a vacuum, the vacuum supply line is plugged. If the pump pulls a partial vacuum, the vacuum supply line is restricted.
- Is the vacuum supply line plugged or restricted?
|
Yes |
Repair or install a new vacuum supply line. Test the system for normal operation. |
| No |
Go to next step. |
| 3 |
CHECK THE VACUUM SUPPLY LINE FOR A LEAK
NOTE:
- The vacuum supply line is grouped with other vacuum lines at a single intake manifold connection. Identify and plug the vacuum supply line only.
- Disconnect and plug the vacuum supply line at the intake manifold.
- Using the vacuum pump SST
, apply 51 kPa (15 in-Hg) of vacuum to the vacuum supply line.
- Does the vacuum supply line lose more than 3.37 kPa (1 in-Hg) of vacuum in one minute?
|
Yes |
Repair or install a new vacuum supply line. Test the system for normal operation. |
| No |
Go to next step. |
| 4 |
CHECK THE VACUUM RESERVOIR TANK
NOTE:
- The A/C vacuum check valve is internal to the vacuum reservoir tank and cannot be serviced separately. This step confirms vacuum reservoir tank integrity and correct operation of the A/C vacuum check valve.
- Connect the vacuum pump SST
to the climate control assembly vacuum source port of the vacuum reservoir tank and apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum reservoir tank lose more than 3.37 kPa (1 in-Hg) of vacuum in one minute?
|
Yes |
Install a new vacuum reservoir tank. Test the system for normal operation. |
| No |
Go to next step. |
| 5 |
CHECK THE VACUUM RESERVOIR TANK FOR OBSTRUCTIONS
- Disconnect the vacuum pump SST
from the vacuum source port of the vacuum reservoir tank.
NOTE:
- The A/C vacuum check valve is internal to the vacuum reservoir tank and cannot be serviced separately. This step confirms correct operation of the A/C vacuum check valve.
- Connect the vacuum pump SST
to the vacuum supply port of the vacuum reservoir tank and try to pull a vacuum. If the pump can pull a vacuum, the vacuum reservoir tank is plugged. If the pump pulls a partial vacuum, the vacuum reservoir tank is restricted.
- Is the vacuum reservoir tank plugged or restricted?
|
Yes |
Install a new vacuum reservoir tank. Test the system for normal operation. |
| No |
Go to next step. |
| 6 |
LEAK TEST THE VACUUM SOURCE LINE
- Disconnect the vacuum pump SST
from the vacuum reservoir tank.
- Disconnect the jumper vacuum harness from the function selector switch.
- Plug the black vacuum source line at the jumper vacuum harness.
- Connect the vacuum pump SST
to the vacuum source line and apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum source line lose more than 3.37 kPa (1 in-Hg) of vacuum in one minute?
|
Yes |
Repair or install a new vacuum source line. Test the system for normal operation. |
| No |
Go to next step. |
| 7 |
CHECK THE VACUUM SOURCE LINE FOR OBSTRUCTIONS
- Remove the plug from the black vacuum source line at the jumper vacuum harness.
- Using the vacuum pump SST
, try to pull a vacuum. If the pump can pull a vacuum, the vacuum source line is plugged. If the pump pulls a partial vacuum, the vacuum source line is restricted.
- Is the vacuum source line plugged or restricted?
|
Yes |
Repair or install a new vacuum source line. Test the system for normal operation. |
| No |
Go to next step. |
| 8 |
LEAK TEST THE FUNCTION SELECTOR SWITCH
- Disconnect the vacuum pump SST
from the vacuum source line.
- Connect the vacuum pump SST
to the vacuum source port of the function selector switch and plug all other ports.
- Apply 51 kPa (15 in-Hg) of vacuum at each function selector switch position and check for vacuum drop.
- Does the function selector switch lose vacuum?
|
Yes |
Install a new function selector switch. Test the system for normal operation. |
| No |
Go to next step. |
| 9 |
CHECK THE FUNCTION SELECTOR SWITCH FOR BLOCKAGE
- Connect the vacuum pump SST
to the vacuum source port of the function selector switch and try to pull a vacuum in each function selector switch position except DEFROST. If the vacuum pump can pull and hold a vacuum, the switch is plugged. If the vacuum pump pulls a vacuum that slowly decays, the switch is restricted.
- Is the switch plugged or restricted?
|
Yes |
Install a new function selector switch. Test the system for normal operation. |
| No |
Go to next step. |
| 10 |
CHECK THE VACUUM HARNESS
- Disconnect the vacuum pump SST
and plugs from the function selector switch.
- Connect the vacuum pump SST
to each vacuum line of the jumper vacuum harness, excluding the black vacuum source line, and apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum harness line lose more than 3.37 kPa (1 in-Hg) of vacuum in one minute?
|
Yes |
Note the vacuum harness line where the vacuum drops. Go to next step. |
| No |
Go to step 12. |
| 11 |
CHECK THE VACUUM CONTROL MOTOR
- Disconnect the vacuum pump SST
from the jumper vacuum harness.
- Disconnect the vacuum line from the vacuum control motor of the vacuum circuit indicated in the previous step.
- Connect the vacuum pump SST
to the vacuum control motor and apply 51 kPa (15 in-Hg) of vacuum.
- Does the vacuum control motor actuate and hold vacuum?
|
Yes |
Repair or install a new vacuum harness. Test the system for normal operation |
| No |
Install a new vacuum control motor. Test the system for normal operation. |
| 12 |
CHECK THE PLENUM VACUUM HARNESS FOR OBSTRUCTIONS
- Disconnect the vacuum line from each vacuum control motor.
- Connect the vacuum pump SST
to each line of the jumper vacuum harness, excluding the black vacuum source line, and try to pull a vacuum. If the pump pulls a vacuum, the vacuum line is plugged. If the pump pulls a partial vacuum, the vacuum line is restricted.
- Is a vacuum line plugged or restricted?
|
Yes |
Repair or install a new vacuum harness. Test the system for normal operation. |
| No |
Go to next step. |
| 13 |
INSPECT THE INSTALLATION OF THE VACUUM CONTROL MOTORS
- Inspect the attachment of the vacuum control motor arms to the air distribution doors.
- Are the vacuum control motor arms connected to the air distribution doors or door levers?
|
Yes |
Repair or install a new air distribution door. Test the system for normal operation. |
| No |
Connect the vacuum control motor arm to the air distribution door or door lever. Test the system for normal operation. |