Fuel Pump Amperage Test

This amperage (current draw) test is to be done in conjunction with the Fuel Pump Pressure Test, Fuel Pump Capacity Test and Fuel Pressure Leak Down Test. Before performing the amperage test, be sure the temperature of the fuel tank is above 50° F (10° C).

The DRB Scan Tool along with the DRB Low Current Shunt (LCS) adapter and its test leads will be used to check fuel pump amperage specifications.

Low Current Shunt Adapter:

1. Obtain LCS adapter.
2. Plug cable from LCS adapter into DRB scan tool at SET 1 receptacle.
3. Plug DRB into vehicle 16-way connector (data link connector).
4. Connect (-) and (+) test cable leads into LCS adapter receptacles. Use 10 amp (10A +) receptacle and common (-) receptacles.
5. Gain access to MAIN MENU on DRB screen.
6. Press DVOM button on DRB.
7. Using left/right arrow keys, highlight CHANNEL 1 function on DRB screen.
8. Press ENTER three times.
9. Using up/down arrow keys, highlight RANGE on DRB screen (screen will default to 2 amp scale).
10. Press ENTER to change 2 amp scale to 10 amp scale. This step must be done to prevent damage to DRB scan tool or LCS adapter (blown fuse).
11. Remove cover from Power Distribution Center (PDC).
12. Remove fuel pump relay from PDC. Refer to label on PDC cover for relay location.

WARNING: BEFORE PROCEEDING TO NEXT STEP, NOTE THE FUEL PUMP WILL BE ACTIVATED AND SYSTEM PRESSURE WILL BE PRESENT. THIS WILL OCCUR AFTER CONNECTING TEST LEADS FROM LCS ADAPTER INTO FUEL PUMP RELAY CAVITIES. THE FUEL PUMP WILL OPERATE EVEN WITH IGNITION KEY IN OFF POSITION. BEFORE ATTACHING TEST LEADS, BE SURE ALL FUEL LINES AND FUEL SYSTEM COMPONENTS ARE CONNECTED.

CAUTION: To prevent possible damage to the vehicle electrical system and LCS adapter, the test leads must be connected into relay cavities exactly as shown in following steps. Depending upon vehicle model, year or engine configuration, three different types of relays may be used: Type-1, type-2 and type-3.

Starter Relay:

13 If equipped with type-1 relay, attach test leads from LCS adapter into PDC relay cavities number 30 and 87. For location of these cavities, refer to numbers stamped to bottom of relay.

Type-2 Relay:

14. If equipped with type-2 relay, attach test leads from LCS adapter into PDC relay cavities number 30 and 87. For location of these cavities, refer to numbers stamped to bottom of relay.

Type-3 Relay:

15. If equipped with type-3 relay, attach test leads from LCS adapter into PDC relay cavities number 3 and 5. For location of these cavities, refer to numbers stamped to bottom of relay.
16. When LCS adapter test leads are attached into relay cavities, fuel pump will be activated. Determine fuel pump amperage on DRB screen. Amperage should be below 10.0 amps. If amperage is below 10.0 amps, and specifications for the Fuel Pump Pressure, Fuel Pump Capacity and Fuel Pressure Leak Down tests were met, the fuel pump module is OK.
17. If amperage is more than 10.0 amps, replace fuel pump module assembly The electric fuel pump is not serviced separately.
18. Disconnect test leads from relay cavities immediately after testing.