Circuit Description
The PCM provides a 5 volt supply for use in powering up the sensors. This test monitors the voltage present at terminals BRD13 (shared by Boost and Crankshaft Position sensors) and BRD14 (the Optical/Fuel temperature sensor (Cam/HI. Res)).
Conditions for Setting the DTC
5 volt reference is less than 1 volt.
Action Taken When the DTC Sets
| • | The PCM will not illuminate the Malfunction Indicator Lamp (MIL). |
| • | The PCM records the operating conditions at the time the diagnostic fails. This information stores in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle). |
| • | Use of a Scan tool will clear the DTC codes. |
Diagnostic Aids
During the time the failure is present, the setting of additional DTCs that share a 5 volt reference may also set.
Test Description
The number(s) below refer to the step number(s) on the Diagnostic Table.
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Checks to confirm that a DTC is still present.
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Checks to determine if there is a 5 volt reference from the PCM.
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Checks to determine if there is a short-to-ground in the reference circuit or a short-to-ground in the PCM.
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This step determines if the short is being caused by one of the senosr on the engine or the short is in the wiring harness.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Important: Before clearing any DTCs, use the scan tool Capture Info to save Freeze Frame and the failure records for reference, as the scan tool loses data when using the Clear Info function. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
Does the DTC reset? | -- | |||
Is the voltage less than the specified value? | 4.0 V | |||
Is the test lamp ON? | -- | |||
5 | The DTC is intermittent. If no additional DTCs are stored, refer to the Diagnostic Aids. If any additional DTCs were stored, refer to those table(s). Are there any additional DTCs stored? | -- | Go to the applicable DTC table | Go to Diagnostic Aids |
6 | Replace the baro sensor. Refer to Barometric Pressure Sensor Replacement . Is the action complete? | -- | -- | |
With the test lamp still probing the baro sensor 5 volt reference circuit at the PCM, disconnect each sensor, one at a time, that shares the 5 volt reference with the baro sensor. Does the test lamp turn OFF when one of the sensors are disconnected? | -- | |||
8 |
Is the test lamp ON? | -- | ||
9 | Replace the sensor that caused the test light to turn OFF. Is the action complete? | -- | -- | |
10 | Repair a short to ground in a 5 volt reference circuit. Is the action complete? | -- | -- | |
11 | Replace the PCM. Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | -- | |
12 |
Does the Scan Tool indicate that this diagnostic Passed? | -- | ||
13 | Does the scan tool display any additional undiagnosed DTCs? | -- | Go to the Applicable DTC table | System OK |
