Diagnostic Aids
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
- Always verify coolant freeze point protection if a fault occurs in cold climate conditions. An improper coolant to water ratio may result in slushy or frozen coolant, resulting in DTCs or overheating. Measure coolant concentration using the J-26568 refractometer or equivalent to verify a 50/50 mix and freeze protection to -37°C (-34°F).
- The Coolant Pump Feedback parameter on the scan tool indicates the status of the pump. When the pump self-diagnostics indicate normal operation, the parameter will indicate a PWM between 45 and 55%. Different PWM values will identify when a pump self-diagnostic has failed:
Coolant Pump Feedback Parameter
| Displayed PWM Value | Pump Self-Diagnostic Indication |
|---|---|
| 0% | Pump has lost power/ground, feedback circuit open, or Vehicle is On* |
| 10% | Pump Under Voltage detected* |
| 20% | Pump Under/Over Current detected* |
| 30% | Blocked or Dry pump detected* |
| 45-55% | Normal operation, actual pump speed provided by circuit frequency |
| 80% | Pump Over Voltage detected* |
| 90% | Pump Over Temperature detected* |
| 100% | Feedback circuit shorted to ground* |
| *Coolant Pump Speed parameter defaults to 50 RPM, actual pump speed is 0 RPM. | |