Circuit Description
The PCM operates a solenoid to control boost. This solenoid is normally open. By providing a ground path the PCM energizes the solenoid which then allows vacuum to pass to the wastegate valve. During normal operation, the PCM compares its wastegate duty cycle signal with the boost signal and makes corrections in the duty cycle accordingly. This is a type B DTC.
Conditions for Setting the DTC
| • | Boost Pressure less than 40 kPa. |
| • | Condition met for 2 seconds. |
Action Taken When the DTC Sets
No turbo boost.
Conditions for Clearing the MIL/DTC
| • | The PCM will turn the MIL off after three consecutive trips without a fault condition. |
| • | A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle. |
| • | Use of a Scan Tool |
Diagnostic Aids
With the ignition ON and the engine stopped, boost pressure is equal to atmospheric pressure. Comparison of this reading with a known good vehicle using the same sensor is a good way to check accuracy of a suspect sensor. Readings should be the same + .4 volt. Very little boost can be attained by revving the engine in neutral. If the Boost sensor signal circuit is open or shorted to ground, Boost solenoid will show a zero duty cycle. A J 39200 can be used to measure (actual) signal voltage at the PCM harness connector.
Test Description
Number(s) below refer to the Step number(s) on the Diagnostic Table.
-
This Step will determine if DTC P0237 is the result of a hard failure or an intermittent condition.
-
This Step simulates conditions for a DTC P0237. If the PCM recognizes the change, the PCM and signal circuit are OK.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing DTCs use the scan tool Capture Info to record freeze frame and failure records for reference, as data will be lost when Clear Info function is used. Was the On-Board Diagnostic (OBD) system check performed? | -- | ||
Does the J 39200 display a voltage less than the specified value? | 1 V (40 kPa) | |||
Does the scan tool display a Boost Pressure greater than the specified value? | 202 kPa | |||
4 |
Does the scan tool display a Boost Pressure greater than the specified value? | 202 kPa (4.0 V) | ||
5 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs are stored, refer to those chart(s) first. Are additional DTCs stored? | -- | Go to the Applicable DTC Table | Go to Diagnostic Aids |
6 | Check for a faulty connection at the Boost sensor. Was a problem found? | -- | ||
7 | Check for an open or a short to ground in Boost sensor signal circuit. Was a problem found? | -- | ||
8 | Check for an open in the Boost sensor 5 volt reference circuit. Was a problem found? | -- | ||
9 | Check for a short to ground in the Boost sensor 5 volt reference circuit. Was a problem found? | -- | ||
10 | Replace the faulty Boost sensor. Refer to Boost Sensor (Diesel) . Is the action complete? | -- | -- | |
11 | Repair the circuit as necessary. Is the action complete? | -- | -- | |
12 | Replace the faulty PCM. Important: If the PCM is faulty, the new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
13 |
Does the Scan Tool indicate that this diagnostic Ran and Passed? | -- | ||
14 | Using the Scan Tool, select Capture Info, Review Info. Are any DTCs displayed that have not been diagnosed? | -- | Go to the Applicable DTC Table | System OK |
