Fuel Transfer Pump And Fuel Pump Relay, Checking
Models with an airbag are installed with a crash fuel shut-off system. It reduces the danger of a fire in a crash as the fuel pump is switched off via the fuel pump relay.
When the door is opened or the Ignition is Switched to the On position; The fuel pump is activated for 2 seconds to build up the pressure in the fuel system.
Special tools and workshop equipment required
- Multimeter.
- Electrical connector test lead set.
Test conditions
- Battery voltage at least 12.5 volts..
- Fuel filter OK.
- Switch the ignition Off.
Test procedure
-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK
Start diagnosis
Make sure the engine is at room temperature.
-- Disconnect the Fuel Pump Relay -J17- electrical harness connector. Refer to applicable wiring diagram for proper relay location.
-- Switch the ignition ON.
-- Using a Multimeter, Check the Fuel Pump Relay -J17- electrical harness connector terminals 1 and 3 to Engine ground for voltage.
Specified value: Battery Voltage
-- Switch the ignition Off.
Continue test according to the following table:
| Value | Cause | Test |
|---|---|---|
| If the specified value was not obtained: | Open or shorted circuit | FUEL TRANSFER PUMP AND FUEL PUMP RELAY, CHECKING => Checking wiring |
| If the specified value was obtained: | Check reference signal circuit | FUEL TRANSFER PUMP AND FUEL PUMP RELAY, CHECKING => Checking Activation |
Checking wiring
-- Using a Multimeter, Check the Fuel Pump Relay -J17- electrical harness connector terminals for resistance, Refer to applicable wiring diagram for fuse location and number.
| Fuel Pump Relay -J17- electrical harness connector terminals | Measure to: |
|---|---|
| 1 | Fuse, Refer to applicable wiring diagram for fuse location and number. |
| 3 | Fuse, Refer to applicable wiring diagram for fuse location and number. |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring connection for an open circuit, short circuit to Battery positive or Ground
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection and replace any open fuses.
-- Go to Final procedures
If the specified value was obtained:
-- Install a jumper wire from Fuel Pump Relay -J17- Terminal 3 to 5
-- Switch the ignition ON.
The Fuel Pump (FP) runs quietly. Avoid surrounding noises while testing the fuel pump.
Specified value: Transfer Fuel Pump -G6- should be operating (Fuel Pump should be heard running).
-- Switch the ignition Off.
Continue test according to the following table:
| Value | Cause | Test |
|---|---|---|
| If the specified value was not obtained: | Open or shorted circuit | FUEL TRANSFER PUMP AND FUEL PUMP RELAY, CHECKING => Checking wiring |
| If the specified value was obtained: | Check reference signal circuit | FUEL TRANSFER PUMP AND FUEL PUMP RELAY, CHECKING => Checking Activation |
Checking wiring
-- Remove the engine control module Engine Control Module -J623-. Refer to the service information for removal and installation procedures.
-- Remove the rear seat bench. Refer to the appropriate service information.
-- Remove cover retainers from the right sealing flange.
-- Disconnect the electrical harness connector from the Transfer Fuel Pump -G6- fuel delivery unit.
-- Using a multimeter, measure the resistance of the circuit between the Transfer Fuel Pump -G6- and the engine control module Engine Control Module -J623-. Refer to the applicable wiring diagram.
| Transfer Fuel Pump -G6- electrical harness connector terminal | Measure to: |
|---|---|
| 1 | Fuel Pump Relay -J17- electrical connector terminal 5 |
| 5 | Engine Control Module -J623- electrical connector terminal T60 / 36 and/or Engine Ground. |
Specified value: 1.5 Ω Max.
If the specification was not obtained:
-- Check the wires for a short circuit to each other, a short to battery voltage, and a short to ground.
-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
-- Repair as necessary.
-- Go to Final procedures
If the specified value was obtained:
-- Replace the Transfer Fuel Pump -G6- delivery unit.
-- Go to Final procedures
Checking Activation
When the door is opened or the Ignition is Switched to the On position; The fuel pump is activated for 2 seconds to build up the pressure in the fuel system.
-- Switch the ignition ON.
-- Using a Multimeter, Check the Fuel Pump Relay -J17- electrical harness connector terminals 2 and 3 for voltage.
Specified value: Battery Voltage for 2 s
-- Switch the ignition Off.
If the specified value was obtained:
-- Replace the Fuel Pump Relay -J17- and retest for operation.
If the specified value was Not obtained:
-- Remove the Engine Control Module (ECM) - J623-. Refer to appropriate service information.
-- Using a Multimeter, Check the Fuel Pump Relay -J17- electrical harness connector to the Engine Control Module (ECM) - J623- electrical harness connector T94 for an open circuit.
| Fuel Pump Relay -J17- electrical harness connector terminals | Engine Control Module (ECM) - J623- electrical harness connector T94 terminals. |
|---|---|
| 2 | 46 |
Specified value: 1.5 Ω Max.
If the specified value was Not obtained:
-- Check the wiring connection for an open circuit, short circuit to Battery positive or Ground
-- Check the wiring connection for damage, corrosion, loose or broken terminals.
-- If necessary, repair the faulty wiring connection.
-- Go to Final procedures
If the specified value was obtained:
-- Replace the Engine Control Module -J623-. Refer to appropriate service information.
Final procedures
-- Make sure Transfer fuel pump relay has been reinstalled properly and all connectors have been plugged back in.
-- Reinstall the engine cover with air filter, if necessary. Refer to the appropriate service information.
-- After the repair work, the following work steps must be performed in the following sequence:
- Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
- If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
- If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .