Circuit/System Verification
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
This diagnostic assumes the following:
- The battery is completely charged.
- The engine cranking speed is acceptable.
- There is adequate fuel in the fuel tank.
- Crank the engine for up to 15 s.
- Verify that no DTC is set.
- If any of the DTCs are set
Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Go to next step: If none of the DTCs are set
- If any of the DTCs are set
- Ignition ON.
- Verify the Theft Deterrent indicator located in the driver information center illuminates momentarily.
- If the indicator stays ON or is flashing
Refer to Symptoms - Theft Deterrent .
- Go to next step: If the indicator does not stay ON and is not flashing
- If the indicator stays ON or is flashing
- Verify the scan tool Engine Speed parameter is greater than 0 RPM while cranking the engine.
- If 0 RPM
Refer to DTC P0335 or P0336 for further diagnosis.
- Go to next step: If greater than 0 RPM
- If 0 RPM
- Ignition OFF.
- Disconnect a T8 Ignition coil from a cylinder.
- Connect a J 26792 HEI Spark Tester between the boot of the T8 Ignition Coil and ground.
- An erratic or weak spark is considered a no spark condition.
- Perform the spark test on at least 3 of the cylinders.
- Verify the spark tester sparks while cranking the engine.
- If the spark tester does not spark
Refer to Electronic Ignition System Diagnosis .
- Go to next step: If the spark tester sparks
- If the spark tester does not spark
- Ignition ON.
- If the engine is too hot, high fuel pressure readings may result due to hot soak fuel boiling. Allow the engine coolant temperature to cool to less than 60° C (150° F) before attempting to verify fuel pressure.
- The Fuel Pump Enable may need to be commanded On a few times in order to obtain the highest possible fuel pressure.
- Command the Chassis Control Module Fuel Pump On several times with a scan tool.
- Verify that the scan tool Chassis Control Module Fuel Pressure Sensor parameter is between 345 - 650 kPa (50 - 94 psi) with the fuel pump running.
- If not within the specified range
Refer to Fuel System Diagnosis .
- Go to next step: If within the specified range
- If not within the specified range
- Verify that the scan tool Chassis Control Module Fuel Pressure Sensor parameter, after the fuel pump has turned OFF, decreases to less than 600 kPa (87 psi), and does not decrease greater than 34 kPa (5 psi) in 1 minute.
- If not within the specified range
Refer to Fuel System Diagnosis .
- Go to next step: If within the specified range
- If not within the specified range
- Verify the conditions listed below do not exist:
- Collapsed air intake duct to the throttle body
- Restricted air filter element
- Spark plugs for being gas or coolant fouled.
- A skewed B74 Manifold Absolute Pressure (MAP) sensor, Compare the B74 Manifold Absolute Pressure Sensor parameter to the Altitude Versus Barometric Pressure table. Refer to Altitude Versus Barometric Pressure .
- A skewed B34 Engine Coolant Temperature (ECT) sensor. Compare the B34 Engine Coolant Temperature Sensor parameter to the Temperature Versus Resistance table. Refer to Temperature Versus Resistance - Engine Coolant Temperature Sensor .
- Exhaust system restricted. Refer to Restricted Exhaust .
- Fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Engine mechanical condition, for example low compression. Refer to Symptoms - Engine Mechanical .
- If a condition exists
Repair as necessary.
- Go to next step: If no condition exists
- All OK.
NOTE:
NOTE: