DTC P0641 Without RPO CTF
Circuit Description
The engine control module (ECM) provides 5 volts for the accelerator pedal position (APP) sensor 1.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The circuit voltage is more than 5.5 volts. |
| • | The circuit voltage is less than 4.5 volts. |
| • | The above conditions are met for 0.7 seconds. |
Action Taken When the DTC Sets
The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.
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:
| • | A poor connection at the ECM connector |
| • | A poor connection at the battery connector |
| • | A harness short |
| • | A defect at the sensor |
Step | Action | Values | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||||||
2 |
Does the scan tool display the DTC? | -- | Go to Step 3 | Go to Intermittent Conditions | ||||||||
3 |
Does the voltage measure within the specified range? | 4.5-5.5 V | Go to Step 4 | Go to Step 6 | ||||||||
4 |
Does the resistance of the APP 1 sensor change while moving the accelerator pedal? | -- | Go to Step 6 | Go to Step 5 | ||||||||
5 | Replace the APP sensor. Did you complete the replacement? | -- | Go to Step 8 | -- | ||||||||
6 | Inspect for the following conditions:
Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 7 | ||||||||
7 | Replace the ECM. Did you complete the replacement? | -- | Go to Step 8 | -- | ||||||||
8 |
Does the DTC run and pass? | -- | Go to Step 9 | Go to Step 2 | ||||||||
9 | Observe the stored information, Capture Info with a scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |||||||||
DTC P0641 With RPO CTF
Circuit Description
The engine control module (ECM) provides a 5-volt reference to the following sensors:
| • | The accelerator pedal position sensor |
| • | The power take off (PTO) accelerator position sensor |
| • | The oil pressure sensor |
| • | Boost sensor |
| • | The exhaust gas recirculation (EGR) position sensor |
| • | The variable nozzle turbo (VNT) position sensor |
| • | The fuel rail pressure sensor |
The 5-volt reference circuits are independent of each other outside the ECM, but are bussed together inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect the sensor 5-volt reference 1 circuits. The ECM monitors the voltage on the 5-volt reference 1 circuit. If the ECM detects that the voltage is out of tolerance, this DTC will set.
Conditions for Running the DTC
| • | The ignition switch is ON. |
| • | The battery voltage is between 10-16 volts. |
Conditions for Setting the DTC
The 5-volt reference circuit 1 voltage is more than 5.5 volts or less than 4.5 volts.
Action Taken When the DTC Sets
| • | The ECM limits fuel injection quantity for fail-safe operation. |
| • | The ECM limits fuel pressure for fail-safe operation. |
| • | The ECM closes the EGR valve and holds it in the closed position. |
| • | The PTO control is inhibited. |
| • | 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 inhibits the cruise control. |
Conditions for Clearing the DTC
| • | The MIL resets when the ignition is turned OFF. |
| • | 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 | ||||
|---|---|---|---|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |||||
2 |
Does the DTC fail this ignition? | -- | Go to Step 3 | Go to Intermittent Conditions | ||||
3 |
Is the voltage within the specified range? | 4.5-5.5 V | Go to Step 7 | Go to Step 4 | ||||
4 |
Was a component replaced? | -- | Go to Step 8 | Go to Step 5 | ||||
5 |
Did you find and correct the condition? | -- | Go to Step 8 | Go to Step 6 | ||||
6 |
Important: The new ECM must be programmed. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 8 | |||||
7 | Replace the APP sensor. Refer to Accelerator Pedal Position Sensor Replacement . Did you complete the replacement? | -- | Go to Step 8 | -- | ||||
8 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 9 | ||||
9 | Observe the stored information, Capture Info with a scan tool. Are there any DTCs that you have not diagnosed? | -- | System OK | |||||
