Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Test Description
2004 Oldsmobile Bravada RWDSECTION Test Description
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The number below refers to the step number on the diagnostic table.
- 2: Verifies that the condition that set the DTC is present.
DTC B0159
| Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
| Schematic Reference: Engine Cooling Schematics Connector End View Reference: Cooling System Connector End Views |
||||
| 1 | Did you perform the Engine Cooling Diagnostic System Check? | - | Go to Step 2 | Go to Diagnostic System Check - Engine Cooling |
| 2 |
|
- | Go to Step 3 | Go to Diagnostic Aids |
| 3 |
|
5 V | Go to Step 4 | Go to Step 5 |
| 4 | Measure the voltage from the signal circuit to the low reference circuit of the ambient air temperature sensor. Does the voltage measure near the specified value? |
5 V | Go to Step 7 | Go to Step 6 |
| 5 | Test the signal circuit of the ambient air temperature sensor for a high resistance. Refer to Circuit Testing
and Wiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 8 |
| 6 | Test the low reference circuit of the ambient air temperature sensor for a high resistance. Refer to Circuit Testing
andWiring Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 8 |
| 7 | Inspect for poor connections at the harness connector of the ambient air temperature sensor. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 9 |
| 8 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
in Wiring Systems. Did you find and correct the condition? |
- | Go to Step 11 | Go to Step 10 |
| 9 | Replace the ambient air temperature sensor. Refer to Ambient Air Temperature Sensor Replacement
in HVAC Systems - Automatic. Did you complete the replacement? |
- | Go to Step 11 | - |
| 10 | Replace the HVAC control module. Refer to HVAC Control Module Replacement
in HVAC Systems - Automatic. Did you complete the replacement? |
- | Go to Step 11 | - |
| 11 |
|
- | Go to Step 2 | System OK |
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.