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)).
5 volt reference is less than 1 volt.
• | 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. |
• | 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. |
During the time the failure is present, the setting of additional DTCs that share a 5 volt reference may also set.
The numbers below refer to the step numbers on the Diagnostic Table.
Checks to confirm that a DTC is still present.
Checks to determine if there is a 5 volt reference from the PCM.
Checks to determine if there is a short-to-ground in the reference circuit or a short-to-ground in the PCM.
This step determines if the short is being caused by one of the sensors on the engine or the short is in the wiring harness.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 |
Important: Before clearing the DTCs, use the Scan Tool Capture Info to save the 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? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | |
Does the DTC reset? | -- | |||
Is the voltage less than the specified value? | 4.0 V | |||
Is the test light 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 tables. Are any additional DTCs stored? | -- | Go to the applicable DTC table | Go to Diagnostic Aids |
6 | Replace the Boost sensor. Refer to Boost Sensor Replacement . Is the action complete? | -- | -- | |
With the test light still probing the boost sensor 5 volt reference circuit at the PCM, disconnect each sensor, one at a time, that shares the 5 volt reference with the boost sensor. Does the test light turn OFF when one of the sensors are disconnected? | -- | |||
8 |
Is the test light ON? | -- | ||
9 | Replace the sensor that caused the test light to turn OFF. Is the action complete? | -- | -- | |
10 | Repair the short to ground in a 5 volt reference circuit. Is the action complete? | -- | -- | |
11 |
Important: The new PCM must be programmed. Replace the PCM. Refer to PCM 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 |