DTC P0237 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
The relative boost pressure is lower than -28 kPa (-4 psi) for 1 second or more.
Action Taken When the DTC Sets
Condition for setting the DTC is based on the relative pressure of 0 kPa (0 psi).
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 (9.7 psi) | 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 | |||||
DTC P0237 With RPO CTF
Circuit Description
The boost pressure sensor is located in the intake manifold. The boost pressure sensor is a transducer that varies voltage according to changes in the air pressure inside the intake manifold. The boost pressure sensor has the following circuits:
| • | A 5-volt reference circuit |
| • | A low reference circuit |
| • | A boost pressure sensor signal circuit |
The engine control module (ECM) supplies 5 volts to the boost pressure sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The boost pressure sensor provides a signal to the ECM on the boost pressure signal circuit which is relative to the pressure changes in the manifold. The ECM should detect a low signal voltage at a low boost pressure, such as low engine load. The ECM should detect a high signal voltage at a high boost pressure, such as high engine load. The ECM monitors the boost pressure sensor signal for voltage outside the normal range of the boost pressure sensor. If the ECM detects an excessively low boost pressure sensor signal voltage, this DTC will set.
Conditions for Running the DTC
| • | The battery voltage is between 10-16 volts. |
| • | The ignition switch is ON. |
Conditions for Setting the DTC
The ECM detects that the boost pressure sensor signal voltage is less than 0.1 volt.
Action Taken When the DTC Sets
| • | The ECM illuminates the malfunction indicator lamp (MIL) and reduced engine power indicator lamp, if fitted, when the diagnostic runs and fails. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
| • | The ECM uses a boost pressure substitution of 14.5 psi (100 kPa) when the DTC is set. |
| • | The ECM limits the fuel injection quantity for fail-safe operation. |
| • | The ECM limits the fuel rail pressure for fail-safe operation. |
Conditions for Clearing the DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||||||
2 |
Is DTC P0641 also set? | -- | Go to DTC P0641 | Go to Step 3 | ||||||||
3 |
Is the Boost Pressure Sensor parameter less than the specified value? | 5 psi (34 kPa) | Go to Step 4 | Go to Intermittent Conditions | ||||||||
4 |
in Wiring Systems. Is the DMM voltage more than the specified value? | 4.5 V | Go to Step 5 | Go to Step 6 | ||||||||
5 |
Is the Boost Pressure Sensor parameter more than the specified value? | 36 psi (254 kPa) | Go to Step 8 | Go to Step 7 | ||||||||
6 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 | ||||||||
7 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 9 | ||||||||
8 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 | ||||||||
9 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | ||||||||
10 | Replace the boost pressure sensor. Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||||
11 |
Important: The replacement ECM must be programmed. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data and Fuel Injector Flow Rate Programming . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||||
12 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Step 13 | ||||||||
13 | Observe the stored information, Capture Info with a scan tool. Are there any DTCs that you have not diagnosed? | -- | System OK |
