Actuator
Thread Starter
Instructor
Joined: Mar 2011
Posts: 170
Likes: 1
From: Lafayette La
Actuator
I got code BO361. I changed the actuator and confirmed the doors were operating. The old actuator had no broken gears inside and the doors were operating but I changed it anyway with an original GM actuator. I am still getting warm air out of the drivers side vents and cold air out of the passenger side vents. I am at wits end and any suggestion would be beneficial.
Pro
Joined: Aug 2010
Posts: 545
Likes: 4
From: Calgary Alberta
Circuit Description
The HVAC Control Assembly receives a LH electric actuator position signal from the LH electric actuator. The LH electric actuator position sensor is a potentiometer that is tied to a 5 volt reference source through CKT 1791 and to ground through CKT 1798, both from the HVAC Control Assembly. The variable output from the potentiometer feeds back a position signal through CKT 733 to a pull-up resistor located in the HVAC Control Assembly. This signal is used to determine the necessary drive signal to the LH electric actuator motor to provide the proper air mix door position. This value is stored in the Keep Alive Memory (KAM) portion of the HVAC Control Assembly.
Conditions for Setting the DTC
With the ignition in the ON position, CKT 733 is checked continuously.
CKT 733 stays at or near 0 volts.
Action Taken When the DTC Sets
The HVAC Control Assembly stores a DTC B0361 in memory.
No driver warning message will be displayed for this DTC.
Conditions for Clearing the DTC
Using the IPC clearing feature.
Using a scan tool.
A history DTC will clear after 50 consecutive ignition cycles if the conditions for the fault is no longer present.
Diagnostic Aids
If the DTC is a history or an intermittent. Try to perform the tests shown while "wiggling" wiring and connectors, this can often cause the malfunction to appear.
Visually inspect sensor connector and harness for damage, corrosion or water intrusion.
Check for adequate terminal tension, mis-routed harness, rubbed through wire insulation, and broken wire inside insulation.
Install a scan tool to the diagnostic link connector. Turn the ignition switch to the ON position. Select the OUTPUT CONTROL screen in HVAC special functions. Use the MISCELLANEOUS TEST screen to manually drive the LH electric actuator with the scan tool from fully open to fully closed. Monitor the LH MIX MTR POSITION FEEDBACK with the scan tool when this is done. A normal position feedback signal should range between 0-255 counts as the electric actuator is being moved.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Tests for the proper operation of the circuit in the high voltage range.
Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
Tests for a short to ground in the 5 volt reference circuit.
Tests for an open or high resistance in the 5 volt reference circuit.
Step
Action
Value(s)
Yes
No
1
Did you perform the HVAC (CJ2) Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check
2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter in the HVAC data list.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is within the specified range?
5-250 counts
Go to Diagnostic Aids
Go to Step 3
3
Turn OFF the ignition.
Disconnect the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is greater than the specified value?
250 counts
Go to Step 4
Go to Step 8
4
Turn OFF the ignition
Connect a 3 amp fused jumper wire between the signal circuit of the LH Electric Actuator and the ground circuit of the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is less than the specified value?
5 counts
Go to Step 5
Go to Step 9
5
Turn OFF the ignition
Disconnect the fused jumper wire.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the LH Electric Actuator and the signal circuit of the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is greater than the specified value?
250 counts
Go to Step 7
Go to Step 6
6
Test the 5 volt reference circuit of the LH Electric Actuator for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
7
Test the 5 volt reference circuit of the LH Electric Actuator for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 11
8
Test the signal circuit of the LH Electric Actuator for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
9
Test the signal circuit of the LH Electric Actuator for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 10
10
Test the ground circuit of the LH Electric Actuator for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
11
Inspect for poor connections at the harness connector of the LH Electric Actuator. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 13
12
Inspect for poor connections at the harness connector of the HVAC Control Assembly. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 14
13
Replace the LH Electric Actuator. Refer to Temperature Actuator Replacement .
Did you complete the replacement?
--
Go to Step 15
--
14
Replace the HVAC Control Assembly. Refer to Control Assembly Replacement .
Did you complete the replacement?
--
Go to Step 15
--
15
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK
--------------------------------------------------------------------------------
Document ID# 545882
2000 Chevrolet/Geo Corvette
The HVAC Control Assembly receives a LH electric actuator position signal from the LH electric actuator. The LH electric actuator position sensor is a potentiometer that is tied to a 5 volt reference source through CKT 1791 and to ground through CKT 1798, both from the HVAC Control Assembly. The variable output from the potentiometer feeds back a position signal through CKT 733 to a pull-up resistor located in the HVAC Control Assembly. This signal is used to determine the necessary drive signal to the LH electric actuator motor to provide the proper air mix door position. This value is stored in the Keep Alive Memory (KAM) portion of the HVAC Control Assembly.
Conditions for Setting the DTC
With the ignition in the ON position, CKT 733 is checked continuously.
CKT 733 stays at or near 0 volts.
Action Taken When the DTC Sets
The HVAC Control Assembly stores a DTC B0361 in memory.
No driver warning message will be displayed for this DTC.
Conditions for Clearing the DTC
Using the IPC clearing feature.
Using a scan tool.
A history DTC will clear after 50 consecutive ignition cycles if the conditions for the fault is no longer present.
Diagnostic Aids
If the DTC is a history or an intermittent. Try to perform the tests shown while "wiggling" wiring and connectors, this can often cause the malfunction to appear.
Visually inspect sensor connector and harness for damage, corrosion or water intrusion.
Check for adequate terminal tension, mis-routed harness, rubbed through wire insulation, and broken wire inside insulation.
Install a scan tool to the diagnostic link connector. Turn the ignition switch to the ON position. Select the OUTPUT CONTROL screen in HVAC special functions. Use the MISCELLANEOUS TEST screen to manually drive the LH electric actuator with the scan tool from fully open to fully closed. Monitor the LH MIX MTR POSITION FEEDBACK with the scan tool when this is done. A normal position feedback signal should range between 0-255 counts as the electric actuator is being moved.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Tests for the proper operation of the circuit in the high voltage range.
Tests for the proper operation of the circuit in the low voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to voltage.
Tests for a short to ground in the 5 volt reference circuit.
Tests for an open or high resistance in the 5 volt reference circuit.
Step
Action
Value(s)
Yes
No
1
Did you perform the HVAC (CJ2) Diagnostic System Check?
--
Go to Step 2
Go to Diagnostic System Check
2
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter in the HVAC data list.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is within the specified range?
5-250 counts
Go to Diagnostic Aids
Go to Step 3
3
Turn OFF the ignition.
Disconnect the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is greater than the specified value?
250 counts
Go to Step 4
Go to Step 8
4
Turn OFF the ignition
Connect a 3 amp fused jumper wire between the signal circuit of the LH Electric Actuator and the ground circuit of the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is less than the specified value?
5 counts
Go to Step 5
Go to Step 9
5
Turn OFF the ignition
Disconnect the fused jumper wire.
Connect a 3 amp fused jumper wire between the 5 volt reference circuit of the LH Electric Actuator and the signal circuit of the LH Electric Actuator.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the LH MIX MTR POSITION FEEDBACK parameter.
Does the scan tool indicate that the LH MIX MTR POSITION FEEDBACK parameter is greater than the specified value?
250 counts
Go to Step 7
Go to Step 6
6
Test the 5 volt reference circuit of the LH Electric Actuator for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
7
Test the 5 volt reference circuit of the LH Electric Actuator for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 11
8
Test the signal circuit of the LH Electric Actuator for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
9
Test the signal circuit of the LH Electric Actuator for a short to voltage, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 10
10
Test the ground circuit of the LH Electric Actuator for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 12
11
Inspect for poor connections at the harness connector of the LH Electric Actuator. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 13
12
Inspect for poor connections at the harness connector of the HVAC Control Assembly. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
--
Go to Step 15
Go to Step 14
13
Replace the LH Electric Actuator. Refer to Temperature Actuator Replacement .
Did you complete the replacement?
--
Go to Step 15
--
14
Replace the HVAC Control Assembly. Refer to Control Assembly Replacement .
Did you complete the replacement?
--
Go to Step 15
--
15
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK
--------------------------------------------------------------------------------
Document ID# 545882
2000 Chevrolet/Geo Corvette
