Circuit Description
The heater-A/C control receives a RH electric actuator position signal from the RH electric actuator. The RH electric actuator position sensor is a potentiometer that is tied to a 5V source through circuit 1217 (PNK/BLK) and to ground through circuit 61 (YEL), both from the heater-A/C control. The variable output from the potentiometer feeds back a position signal through circuit 1791 (YEL) to a pull-up resistor in the heater-A/C control. This signal relates to the position of the RH electric actuator. This signal is used to determine the necessary drive signal to the RH electric actuator motor to provide the proper air mix door position.
Conditions for Setting the DTC
The heater-A/C control performs an internal check on the RH electric actuator position and determines the RH electric actuator is out of range.
Action Taken When the DTC Sets
The heater-A/C control stores DTC B0446 in memory.
Conditions for Clearing the DTC
| • | Under all fault conditions, the ignition switch must be cycled from on to off, back to on before this DTC can change from current to history. |
| • | A history DTC will clear after 100 drive cycles if the condition for this malfunction is no longer present. |
| • | Using a scan tool. |
Diagnostic Aids
The following conditions may cause DTC B0446 to set:
| • | A voltage spike in circuit 1791 (YEL). |
| • | A short to ground in circuit 1217 (PNK/BLK) |
| • | A short to B+ in circuit 1791 (YEL). |
| • | An open in circuit 61(YEL), 1217 (PNK/BLK) or 1791 (YEL). |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This test checks if the heater-A/C control 5V supply is getting through circuit 1217 (PNK/BLK).
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This test checks if the heater-A/C control 5V supply is getting through circuit 1791 (YEL).
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This test checks if the heater-A/C control ground is getting through circuit 61 (YEL).
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the heater-A/C control diagnostic system check performed? | -- | Go to Step 2 | Go to Diagnostic System Check |
Is the measured voltage within the specified range? | 4.5-5.5V | Go to Step 3 | Go to Step 5 | |
Use a DMM, measure the voltage between the RH electric actuator harness connector terminal 7 and terminal 10. Is the measured voltage within the specified range? | 4.5-5.5V | Go to Step 4 | Go to Step 8 | |
Using a DMM to measure the voltage between the RH electric actuator harness connector terminal 9 and ground. Is the measured voltage within the specified range? | 4.5-5.5V | Go to Step 12 | Go to Step 9 | |
5 | Check circuit 1217 (PNK/BLK) for a short to ground. Is there a short to ground in circuit 1217 (PNK/BLK) ? | -- | Go to Step 6 | Go to Step 7 |
6 | Locate and repair the short to ground in circuit 1217 (PNK/BLK) . Is the repair complete? | -- | System OK | -- |
7 |
Is the repair complete? | -- | System OK | -- |
8 |
Is the repair complete? | -- | System OK | -- |
9 | Check circuit 1791 (YEL) for a short to B+ or short to ground. Is there a short to B+ or short to ground in circuit 1791 (YEL)? | -- | Go to Step 10 | Go to Step 11 |
10 | Locate and repair the short to B+ or short to ground in circuit 1791 (YEL). Is the repair complete? | -- | System OK | -- |
11 |
Is the repair complete? | -- | System OK | -- |
12 | Replace the RH electric actuator. Refer to Temperature Actuator Replacement (RH (Passenger)) . Is the repair complete? | -- | System OK | -- |
