| Table 1: | Normal Value - When VCC = 5V |
| Table 2: | Guide Line Value - When BARO = 100 kPa |
Circuit Description
The boost pressure sensor is fixed on the cab back frame and is connected to rear portion of inlet manifold by a vacuum hose.
The boost pressure sensor generates voltage according to air aspiration pressure and the generated voltage is input to the engine control module (ECM) for boost pressure sensor signal.
If the ECM detects a boost pressure sensor signal voltage that is excessively high, DTC 0042 or 0032 will set.
Conditions for Setting the DTC
No engine stall, abnormal boost pressure, boost pressure sensor normal condition, and high boost pressure signal for 0.5 second or more.
Action Taken When the DTC Sets
The injection amount map is used as a fail-safe mode.
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
DTC 0042 or 0032 can be cleared by using the Clear Info on the scan tool or by using the Diag Clear Switch.
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connection at the ECM |
| Inspect the harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal-to-wire connection. |
| • | Damaged harness |
| Inspect the wiring harness for damage, shorts to ground, shorts to battery, and open circuits. If the harness appears to be OK, observe the boost pressure display on the scan tool while moving connectors and wiring harnesses related to the boost pressure sensor. A change in the scan tool display will indicate the location of the fault. |
| • | Lack of engine power etc. |
Boost Pressure | Sensor Voltage |
80 kPa (11.6 psi) | About 0.7 V Negative pressure |
Atmospheric release | 1 V |
169 kPa (24.5 psi) | 2 V |
Voltage | 3.4 V or more |
Boost Pressure | 162 kPa (23.5 psi) or more |
CKP | About 2,000 RPM |
Acceleration | 100% |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 |
Important: When the barometric pressure (BARO) sensor is abnormal, the BARO is calculated at 100 kPa (14.5 psi). Does DTC 0042 or DTC 0032 set while the ignition is ON or the engine is running? | Go to Step 2 | Go to Diagnostic Aids |
2 |
Does voltage indicate a normal value according to boost pressure? | Go to Step 3 | Go to Step 7 |
3 | Monitor the waste gate pressure with a scan tool. When boost pressure is applied, does waste gate pressure measure normal? | Go to Step 4 | Go to Step 8 |
4 | Inspect for leaking ductwork or a turbocharger problem. Did you find leaking ductwork and/or any problem on the turbocharger? | Go to Step 9 | Go to Step 5 |
5 | Operate the vehicle under the conditions in the guide line value table. Does the actual boost pressure measure near the value in the normal value table? | Go to Step 6 | Go to Step 10 |
6 | Clear the DTCs. Do DTC 0042 or DTC 0032 reset? | Go to Step 11 | System OK |
7 | Replace the boost pressure sensor and/or repair the ductwork. Did you complete the action? | Go to Step 12 | -- |
8 | Repair the wastegate. Did you complete the repair? | Go to Step 12 | -- |
9 | Repair/replace turbocharger problem. Did you complete the action? | Go to Step 12 | -- |
10 | Repair/replace the turbocharger and/or wastegate piping. Did you complete the action? | Go to Step 12 | -- |
11 | Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | Go to Step 12 | -- |
12 | Clear the DTCs. Does DTC 0042 reset? | Go to Step 2 | System OK |
