DTC P0238 Without RPO CTF
Circuit Description
The boost pressure sensor is fixed on the intake manifold and is connected to the intake manifold by a vacuum hose.
The boost pressure sensor generates voltage according to air pressure in the intake manifold and the generated voltage is input to the engine control module (ECM) for the boost sensor signal.
The ECM monitors the boost pressure sensor signals for voltage outside the normal range of the boost pressure sensor. If the ECM detects a boost pressure sensor signal voltage that is excessively low DTC P0237 will set. If the ECM detects a boost pressure sensor signal voltage that is excessively high DTC P0238 will set .
Conditions for Setting the DTC
When the engine stalls and the relative boost pressure is higher than 20 kPa (2.9 psi) for 1 second or more.
Action Taken When the DTC Sets
Condition for setting the DTC Injection amount map is used for 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. |
| • | Clear the MIL and the DTC with a scan tool. |
Diagnostic Aids
Inspect for the following conditions:
| • | Poor connection at the ECM |
| Inspect 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 boost pressure scan tool display will indicate the location of the fault. |
| • | Lack of power due to injection limitation. |
Pressure | Voltage (V) |
|---|---|
67 kPa (9.7psi) | 0.5 V |
200 kPa (29 psi) | 2.5 V |
333 kPa (48 psi) | 4.5 V |
Step | Action | Value | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Does the DTC set with the ignition ON or the engine is running? | -- | Go to Step 2 | Go to Intermittent Conditions | ||||
2 |
Does the voltage measure near the specified value? | 1.3 V | Go to Step 8 | Go to Step 3 | ||||
3 | Measure voltage between pin number C4-5 and pin number C4-15 of the ECM harness connector. Does the voltage measure within the specified range? | 4.75-5.25 V | Go to Step 6 | Go to Step 4 | ||||
4 |
Does each resistance measure less than the specified value? | 0.5 ohms | Go to Step 5 | Go to Step 12 | ||||
5 | Measure the resistance of the following points on the boost sensor harness:
Does each resistance measure more than the specified value? | 10 M ohms | Go to Step 11 | Go to Step 12 | ||||
6 |
Does each resistance measure less than the specified value? | 0.5 ohms | Go to Step 7 | Go to Step 12 | ||||
7 | Measure resistance between the following points on the boost sensor harness:
Does each resistance measure more than the specified value? | 10 M ohms | Go to Step 11 | Go to Step 12 | ||||
8 |
Is voltage created to meet boost pressure? | -- | Go to Step 9 | Go to Step 11 | ||||
9 |
Are there any abnormal boost pressure voltages or any leakage? | -- | Go to Step 10 | Go to Step 13 | ||||
10 | Inspect the turbocharger condition, waste gate opening pressure, and/or piping. Is the opening pressure of the waste gate correct? | Go to Step 17 | Go to Step 15 | |||||
11 | Replace the boost pressure sensor. Did you complete the replacement? | -- | Go to Step 13 | -- | ||||
12 | Repair the boost pressure sensor wiring harness. Did you complete the repair? | -- | Go to Step 13 | -- | ||||
13 | Clear all DTCs. Does the DTC reset? | -- | Go to Step 14 | Go to Step 17 | ||||
14 | Replace the ECM. Did you complete the replacement? | Go to Step 16 | -- | |||||
15 | Repair piping and/or readjust the waste gate opening pressure. Did you complete the repair? | -- | Go to Step 16 | -- | ||||
16 |
Does the DTC reset? | -- | Go to Step 2 | Go to Step 17 | ||||
17 | Do any other DTCs set? | -- | System OK | |||||
