PRE-RELEASE
DTC P0627-P0629
| DTC P0627-P0629 |
| Diagnostic Instructions |
| • |
Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
|
|
| • |
Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
|
|
| • |
Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
|
|
| DTC Descriptors |
DTC P0627
Fuel Pump Relay Control Circuit Open
DTC P0628
Fuel Pump Relay Control Circuit Low Voltage
DTC P0629
Fuel Pump Relay Control Circuit High Voltage
| Diagnostic Fault Information |
| Circuit | Short to Ground | Open/High Resistance | Short to Voltage |
|
Fuel Pump Relay Control
|
P0628
|
P0627
|
P0629
|
| Circuit/System Description |
The engine control module (ECM) supplies voltage to the fuel pump control module when the ECM detects that the ignition is ON. The voltage signal from the ECM to the fuel pump control module remains active for 2 s, unless the engine is in Crank or Run. While this signal is being received, the fuel pump control module closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel pump module in order to maintain the desired fuel pressure.
| Conditions for Running the DTC |
P0627 and P0629
| • |
The ignition voltage is between 10-18.1 V.
|
|
| • |
The ECM has commanded the fuel pump OFF.
|
|
| • |
The above conditions are met for greater than 1 s.
|
|
| • |
The DTCs run continuously when the above conditions are met.
|
|
P0628
| • |
The ignition voltage is between 10-18.1 V.
|
|
| • |
The ECM has commanded the fuel pump ON.
|
|
| • |
The above conditions are met for greater than 1 s.
|
|
| • |
The DTC runs continuously when the above conditions are met.
|
|
| Conditions for Setting the DTC |
P0627
The ECM detects the fuel pump relay control circuit is open.P0628
The ECM detects the fuel pump relay control circuit is shorted to ground.P0629
The ECM detects the fuel pump relay control circuit is shorted to voltage.The DTCs set when the above conditions are met for more than 4 s or a cumulative of 50 s.
| Action Taken When the DTC Sets |
DTCs P0627, P0628, and P0629 are Type C DTCs.
| Conditions for Clearing the DTC |
DTCs P0627, P0628, and P0629 are Type C DTCs.
| Reference Information |
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Electrical Information Reference
| • |
Circuit Testing
|
|
| • |
Connector Repairs
|
|
| • |
Testing for Intermittent Conditions and Poor Connections
|
|
| • |
Wiring Repairs
|
|
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Testing |
| Note | ||
|
Repair all U-codes before performing this diagnostic. |
| 1. |
Ignition OFF, disconnect the harness connector at the K27 fuel pump control module.
|
|
| 2. |
Install a test lamp between the fuel pump control circuit terminal 13 and ground. Verify the test lamp turns ON and OFF as the ignition is turned ON.
|
|
| 3. |
If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
|
|
| 4. |
Ignition ON, verify that a test lamp does not stay illuminated between the fuel pump control circuit terminal 13 and ground.
|
|
| 5. |
If the test lamp stays illuminated, test the control circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.
|
|
| 6. |
If all circuits test normal, test or replace the K27 fuel pump control module.
|
|
| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for ECM or fuel pump control module replacement, setup, and programming
