| Table 1: | Normal Value - When VCC = 5V |
| Table 2: | Guide Line Value - When BARO = 100 kPa |
Circuit Description
The boost pressure sensor is located on the cab back frame and is connected to the intake manifold by a vacuum hose.
The boost pressure sensor generates a voltage according to air 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 low, DTC 0065 will be set.
Conditions for Setting the DTC
| • | The engine is running. |
| • | The accelerator is open more than 80 percent. |
| • | Low boost pressure continues for 25 seconds or more. |
| • | The actual boost pressure is normal. |
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 0065 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. |
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 | 2 V or less |
Boost Pressure | 70 kPa (10 psi) or less |
CKP | 2,000 RPM |
Acceleration | 100% |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 | Does DTC 0065 set while the ignition is ON or the engine is running? | Go to Step 2 | Go to Diagnostic Aids |
2 |
Important: Other boost codes could set when performing this operation. Does the voltage indicate normal value according to boost table? | Go to Step 3 | Go to Step 8 |
3 | Monitor the wastegage pressure with a scan tool. When boost pressure applied, is wastegate pressure normal? | Go to Step 4 | Go to Step 9 |
4 | Is there leakage from ducting and/or any problem on turbocharger? | Go to Step 10 | Go to Step 5 |
5 |
Does the actual boost pressure and voltage indicate guide line value at 80 percent acceleration or more? | Go to Step 6 | Go to Step 11 |
6 | Are any other DTCs set? | Go to Step 12 | Go to Step 7 |
7 | Clear the DTCs. Does DTC 0065 still set? | Go to Step 13 | System OK |
8 |
Important: The actual output voltage of boost sensor will be affected if the supply voltage to the sensor is changed. Replace the boost pressure sensor or repair/replace boost pressure sensor wiring harness. Did you complete the action? | Go to Step 14 | -- |
9 | Repair the wastegate. Did you complete the repair? | Go to Step 14 | -- |
10 | Repair/replace the failed portion. Did you complete the action? | Go to Step 14 | -- |
11 | Replace the boost pressure sensor and/or repair the turbocharger. Did you complete the action? | Go to Step 14 | -- |
12 | Repair other DTCs first. Did you complete the repair? | Go to Step 14 | -- |
13 | Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | Go to Step 14 | -- |
14 | Clear the DTCs. Does DTC 0065 still set? | Go to Step 2 | System OK |
