DTC B018B
Diagnostic Instructions
DTC Descriptors
| DTC B018B 02: HVAC Condenser Air Deflector
Circuit Short to Ground |
| DTC B018B 05: HVAC Condenser Air Deflector
Circuit High Voltage/Open |
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Front Spoiler Air Inlet Actuator Ignition
|
-
|
B018B 05
|
-
|
-
|
Front Spoiler Air Inlet Actuator Control
|
B018B 02
|
B018B 05
|
B018B 05
|
-
|
Front Spoiler Air Inlet Actuator Ground
|
-
|
B018B 05
|
-
|
-
|
|
| |
Circuit/System Description
The front spoiler air inlet actuator closes lamellas at the
front bumper to enhance vehicle aerodynamics in driving situations
where cooling and A/C loads are relatively low and high levels of
front end airflow are not required. If high levels of airflow are
required the front spoiler air inlet actuator opens the lamellas.
The control signal from the HVAC control module, ignition and
ground circuits enable the front spoiler air inlet actuator to
operate. If the conditions for opening the lamellas are reached the
HVAC control module supplies B+ to the control circuit and the
front spoiler air inlet actuator opens the lamellas.
Conditions for Running the DTC
| • |
The HVAC control module is
ON. |
Conditions for Setting the DTC
B018B 02
The HVAC control module detects a short to ground at the front
spoiler air inlet actuator control circuit. The requested status of
the output is ON but output level is OFF.
B018B 05
The HVAC control module detects a short to voltage or an open at
the front spoiler air inlet actuator control circuit. The requested
status of the output is OFF but output level is ON.
Action Taken When the DTC Sets
| • |
The malfunction indicator lamp
(MIL) in the instrument cluster will be illuminated. |
| • |
The output will be switched
off for hardware protection. |
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
HVAC Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Automatic HVAC Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, command the front spoiler air inlet motor ON and
OFF with a scan tool. Observe the front spoiler air inlet actuator
opens and closes the lamellas at the front bumper.
Circuit/System Testing
| 1. |
Ignition OFF, disconnect the
harness connector at the M96 Active Grille Air Shutter
Actuator. |
| 2. |
Test for less than 5 Ω
between the ground circuit terminal 2 and ground. |
⇒ If greater than 5
Ω
Repair the open/high resistance in
the circuit. ⇓ If
less than 5 Ω
| 3. |
Ignition ON, test for greater
than 11 V between the ignition circuit terminal 3 and
ground. |
⇒ If less than 11 V
and the circuit fuse is good
| |
3.2 |
Test for less than 2 Ω
in the ignition circuit end to end. |
| ⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
| ⇒ |
If less than 2 Ω, verify the fuse is not open and there
is voltage at the fuse. |
⇒ If less than 11 V
and the circuit fuse is open
| |
3.2 |
Test for infinite resistance
between the ignition circuit and ground. |
| ⇒ |
If less than infinite resistance, repair the short to ground on
the circuit. |
| ⇒ |
If infinite resistance, replace the M96 Active Grille Air
Shutter Actuator. |
⇓ If greater than 11
V
| 4. |
Connect a test lamp between
the control circuit terminal 1 and the ground circuit terminal
2. |
| 5. |
Command the Front Spoiler Air
Inlet Motor ON and OFF with a scan tool. The test lamp should turn
ON and OFF when changing between the commanded states. |
⇒ If the test lamp
is always ON
| |
5.1 |
Ignition OFF, disconnect the
X2 harness connector at the K33 HVAC Control Module, ignition
ON. |
| |
5.2 |
Test for less than 0.3 V
between the control circuit and ground. |
| ⇒ |
If greater than 0.3 V, repair the short to voltage on the
circuit. |
| ⇒ |
If less than 0.3 V, replace the K33 HVAC Control Module. |
⇒ If the test lamp
is always OFF
| |
5.1 |
Ignition OFF, disconnect the
X2 harness connector at the K33 HVAC Control Module. |
| |
5.2 |
Test for infinite resistance
between the control circuit and ground. |
| ⇒ |
If less than infinite resistance, repair the short to ground on
the circuit. |
| |
5.3 |
Test for less than 2 Ω
in the control circuit end to end. |
| ⇒ |
If 2 Ω or greater, repair the open/high resistance in the
circuit. |
| ⇒ |
If less than 2 Ω, replace the K33 HVAC Control
Module. |
⇓ If the test lamp
turns ON and OFF as commanded
| 6. |
Replace the M96 Active Grille
Air Shutter Actuator. |
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic
procedure.
Control Module References for HVAC control module replacement,
programming and setup
|
