DTC P2635
Diagnostic Instructions
DTC Descriptor
DTC P2635: Fuel Pump Flow Performance
Diagnostic Fault Information
Circuit
|
Short to Ground
|
Open/High Resistance
|
Short to Voltage
|
Signal Performance
|
Control
|
P0231
|
P023F
|
P0232
|
P023F, P2635
|
Low Reference
|
-
|
P023F
|
-
|
P023F, P2635
|
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 from the ECM to the fuel pump control module remains
active for 2 seconds, unless the engine is in crank or run.
While this voltage 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 tank pump module in order to maintain
the desired fuel rail pressure.
Conditions for Running the DTC
• |
DTC P018B, P018C, P018D, P0231, P0232, P023F,
P064A, P1255 or P06A6 are not active. |
• |
DTC P0641 has not failed this ignition
cycle. |
• |
Fuel pump control is enabled and the fuel pump
control state is normal. |
• |
The system voltage is greater than 11 V. |
• |
The engine has been running for more than
30 seconds. |
• |
Low fuel level warning not present. |
Conditions for Setting the DTC
This DTC sets when the fuel pump control module detects a
predetermined fuel pressure performance degradation between the
desired fuel rail pressure and the current estimated fuel rail
pressure.
Action Taken When the DTC Sets
DTC P2635 is a Type B DTC.
Conditions for Clearing the DTC
DTC P2635 is a Type B DTC.
Diagnostic Aids
Using the Failure Records data may help locate an intermittent
condition. If you cannot duplicate the DTC, the information in the
Failure Records can help determine how many miles since the DTC
set. The Fail Counter and Pass Counter can help determine how many
ignition cycles that the diagnostic test reported a pass and/or a
fail.
On vehicles equipped with a high pressure mechanical pump on
Direct Fuel Injection engines, the vehicle may continue to run even
though the pump in the fuel tank is not operating.
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Fuel System Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Testing
- If any of the DTCs are set, verify that
DTCs P018C, P018D, P0231, P0232, or P023F are not set.
- Ignition OFF, disconnect the harness connector at the
G12 fuel pump.
- Ignition OFF, test for less than 5.0 Ω between
the G12 fuel pump low reference circuit terminal 2 and
ground.
⇒ |
If greater than the specified range, test the
G12 fuel pump low reference circuit for a high resistance. If
the circuit tests normal, replace the K27 fuel pump control
module. |
- Ignition OFF, install a test lamp between the control
circuit terminal 1 and the low reference circuit
terminal 2.
- Ignition ON, command the Fuel Pump Relay ON and OFF
with a scan tool. The test lamp should turn ON and OFF when
changing between the commanded states.
⇒ |
If the test lamp is always ON, test the control
circuit for a short to voltage. If the circuit tests normal,
replace the K27 fuel pump control module. |
⇒ |
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 K27 fuel pump control
module. |
- Perform the
Fuel System Diagnosis to verify proper fuel pressure.
⇒ |
If the fuel pressure is not normal, replace the
G12 fuel pump |
- If all circuits test normal, replace the K27 fuel
pump control module.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the repair.
|