Turbocharger Boost Sensor A (TCB-A)
The Turbocharger Boost Sensor A (also known as Throttle Inlet Pressure (TIP)) is the feedback sensor for turbo boost control. Boost control algorithm computes desired boost from operating conditions and adjusts the pneumatically-controlled boost pressure limit to achieve that desired boost pressure. TCB-A is also used to compute air flow rate through the throttle independently of the primary air charge computation for torque monitoring (and intake manifold leak detection).
The TCB-A sensor is physically integrated with the Charge Air Cooler Temperature Sensor. The boost sensor has a specified range of 20 to 300 kPa. The voltage is electrically clipped between 0.3 to 4.8 volts,
TCB-A AND MAP SENSOR TRANSFER FUNCTION
| Vout=(Vref / 5) * (0.0146428 * Pressure (in kPa) + 0.1072) | ||
| Volts | Pressure, kPa | Pressure, Inches Hg |
| 0.3 | 13.16 | 3.89 |
| 0.4 | 20 | 5.91 |
| 0.986 | 60.0 | 17.72 |
| 2.157 | 140 | 41.34 |
| 3.329 | 220.0 | 64.97 |
| 4.5 | 300 | 88.59 |
| 4.8 | 320.49 | 94.64 |
THROTTLE INLET PRESSURE SENSOR RANGE CIRCUIT CHECK
| DTCs | P0237 Turbocharger/Supercharger Boost Sensor A Circuit Low P0238 Turbocharger/Supercharger Boost Sensor A Circuit High |
| Monitor execution | continuous |
| Monitor Sequence | None |
| Sensors OK | not applicable |
| Monitoring Duration | 5 seconds to register a malfunction |
TYPICAL THROTTLE INLET PRESSURE SENSOR RANGE CIRCUIT CHECK MALFUNCTION THRESHOLDS
| P0237 TCB-A voltage < 0.19 volts P0238 TCB_A voltage > 4.88 volts |
THROTTLE INLET PRESSURE SENSOR RANGE CIRCUIT INTERMITTENT CHECK
| DTCs | P025E Turbocharger/Supercharger Boost Sensor "A" Intermittent/Erratic |
| Monitor execution | continuous |
| Monitor Sequence | none |
| Sensors OK | not applicable |
| Monitoring Duration | counts intermittent events per trip |
TYPICAL THROTTLE INLET PRESSURE SENSOR RANGE CIRCUIT MALFUNCTION THRESHOLDS
| 10 intermittent out-of-range events per driving cycle |