The HVAC control module detects exhaust gas by an Air Quality Sensor (AQS).
This diagnostic procedure supports the following DTC :
DTC B3843 Outside Air Quality Sensor Input Voltage
Ignition is ON.
• | The AQS feedback voltage is less than 0.05 V. |
• | The AQS feedback voltage is greater than 4.79 V. |
• | The AQS does not operate function. |
• | The AQS LED is OFF. |
• | The DTC will become history if the HVAC control module no longer detects a fault. |
• | The DTC can be cleared with a scan tool. |
• | Disconnecting the HVAC control module battery feed for 10 seconds. |
The number(s) below refer to the step number(s) on the diagnostic table.
Tests voltage of the AQS. The range is 0 to 5 volt.
Ignition switch is ON and test voltage of the HVAC control module connector terminal A16 and A9.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
Does the scan tool indicate that the power transistor assembly parameter is within the specified range? | 0.05-5.0 V | Go to Step 7 | Go to Step 3 | |
Does the scan tool indicate that the appropriate AQS data parameter is greater than the specified value? | 5.0 V | Go to Step 4 | Go to Step 5 | |
4 |
Does the scan tool indicate that the AQS data parameter is less than the specified value? | 0.05 V | Go to Step 7 | Go to Step 6 |
5 | Test the AQS signal circuit for a short to ground. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
6 | Test the low reference circuit of the AQS for a high resistance, or an open. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
7 | Inspect for poor connections at the harness connector of the AQS. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
8 | Inspect for poor connections at the harness connector of the HVAC module. Did you find and correct the condition? | 5.0V | Go to Step 10 | Go to Step 9 |
9 | Replace the AQS. Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |