Refer to Engine Controls Schematics
PCM Fuel Tank Inputs
.
Circuit Description
The PCM provides ignition positive voltage to control the fuel pump relay. When the ignition switch is turned ON, the PCM energizes the fuel pump relay that applies power to the fuel pump. The fuel pump relay remains ON as long as the engine is running or cranking and the PCM is receiving reference pulses. The PCM has the ability to detect an electrical malfunction on the relay control circuit. If no reference pulses are present, the PCM de-energizes the fuel pump relay within 2 seconds after the ignition is turned ON or the engine is stopped. With the engine stopped, the fuel pump can be turned ON by using the scan tool output controls function. If an electrical malfunction is detected, the PCM will set DTC P0230.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
| • | The PCM detects an electrical malfunction on the fuel pump relay control circuit. |
| • | The condition is present for 0.5 second. |
Action Taken When the DTC Sets
| • | The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | The current DTC will clear when the diagnostic runs and does not fail. |
| • | Use a scan tool in order to clear the MIL diagnostic trouble code. |
| • | Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module Description , Clearing Diagnostic Trouble Codes. |
Diagnostic Aids
Notice: Use the connector test adapter kit J 35616-A for any test that
requires probing the following items:
• The PCM harness connectors • The electrical center fuse/relay cavities • The component terminals • The component harness connector
Reviewing the Failure Records vehicle mileage since the diagnostic test last failed may help determine how often the condition occurs that set the DTC. This may assist in diagnosing the condition.
If the problem is intermittent, refer to Intermittent Conditions .
Relay Terminal Identification
Use the following relay cavity table in order to locate the correct cavities to probe during diagnosis. The table layout corresponds to the cavity layout in the Underhood Accessory Wiring Junction Block. Four blade relays can be inserted two ways. Use the table and NOT the numbering on the relay to avoid probing incorrectly.
Top of Junction Block | |
|---|---|
Fuel Pump Relay | |
Switch Power (Fuse) | Coil Power (PCM) |
Not Used | -- |
Coil Ground | Switch Load (Pump) |
Test Description
Numbers below refer to the step numbers on the diagnostic table:
-
If the fuel pump is not audible at the fuel tank area, listen underhood at the fuel rail. Fuel flowing through the pressure regulator produces an audible hiss.
-
This vehicle is equipped with a PCM that utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
Turn the key to the Off position, wait 15 seconds, then turn the key to the On position and listen for fuel pump operation. The fuel pump should operate for 2 seconds after the key is turned to the On position. The fuel pump can also be commanded on using the scan tool if necessary. Does the fuel pump turn on and off? | -- | Go to Diagnostic Aids. | ||
3 | Is the fuel pump always on? | -- | ||
4 |
Does the test lamp turn On when the fuel pump is commanded On? | -- | ||
5 | Probe the fuel pump relay ground circuit with test lamp J 35616-200 connected to B+. Is the test lamp On? | -- | ||
6 |
Is the test lamp On? | -- | ||
7 |
Was a problem found and corrected? | -- | ||
8 |
Was a problem found and corrected? | -- | ||
9 |
Is the fuel pump running? | -- | ||
10 |
Was a problem found and corrected? | -- | ||
11 | Locate and repair short to ground in the fuel pump relay control circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
12 | Locate and repair open the fuel pump relay ground circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
13 | Locate and repair the short to voltage in the fuel pump relay control circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
14 | Replace the fuel pump relay. Refer to Fuel Pump Relay Replacement . Is the action complete? | -- | -- | |
|
Important: : The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||
16 |
Does the scan tool indicate that this test ran and passed? | -- | ||
17 | Review Captured Info using the scan tool. Are there any DTCs that have not been diagnosed? | -- | Go to the applicable DTC table | System OK |
