Circuit Description
The powertrain control module (PCM) provides 5 volts to the manifold absolute pressure (MAP) sensor.
The PCM monitors the voltage on the 5-volt reference circuit. If the PCM detects that the voltage is out of range, DTC P0651 sets.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0651 5-Volt Reference Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | DTC P0651 runs continuously once the above condition is met. |
Conditions for Setting the DTC
The PCM detects a voltage out of range condition on the 5-volt reference circuit for more than 24 seconds.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records. |
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. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Powertrain Control Module Connector End Views or Engine Controls Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does the DTC fail this ignition cycle? | -- | Go to Step 3 | Go to Intermittent Conditions |
3 |
Is the voltage more than the specified value? | 5.2 V | Go to Step 6 | Go to Step 4 |
4 | Is the voltage measured in the previous step less than the specified value? | 4.8 V | Go to Step 5 | Go to Step 7 |
5 |
Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
6 | Test all 5-volt reference circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8 |
7 | Replace the MAP sensor. Refer to Manifold Absolute Pressure Sensor Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 10 |
10 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information | System OK |
