When the key is turned ON, the powertrain control module (PCM) energizes the fuel pump relay which sends voltage to the lift pump. The lift pump remains ON during the glow plug cycle. If the engine is not started immediately after the glow plug cycle, the PCM shuts the fuel lift pump OFF and waits for the crank reference signal.
Possible long crank times or a poor performance problem will exist.
The numbers below refer to step numbers on the diagnostic table.
Checks for proper operation of the fuel pump.
Checks the operation of the fuel pump by supplying 12 volts to the fuel pump control circuit.
Checks the battery feed circuit to the fuel pump relay.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 |
Important: Before clearing the DTCs, use the Scan Tool Capture Info in order to record the Freeze Frame/Failure Records for reference, as the data will be lost when the Clear Info function is used. Did you perform the Diagnostic System Check-Engine Controls? | Go to Step 2 | |
Does the fuel lift pump operate during the glow plug cycle? | Go to Step 3 | ||
Connect a 20-amp fused jumper wire between the battery voltage circuit of the fuel pump relay and the supply voltage circuit of the fuel pump. Does the fuel pump operate? | Go to Step 4 | Go to Step 8 | |
Does the test lamp illuminate? | Go to Step 5 | Go to Step 10 | |
5 | Connect a test lamp between the fuel pump relay battery feed circuit harness connector and the fuel pump relay ground at the harness connector. Does the test lamp illuminate? | Go to Step 6 | Go to Step 11 |
6 |
Does the test lamp illuminate during glow plug cycle and then OFF? | Go to Step 7 | Go to Step 12 |
7 |
Was a problem found? | Go to Step 18 | Go to Step 13 |
8 |
Does the test lamp illuminate? | Go to Step 9 | Go to Step 15 |
9 | With a test lamp connected to B+ probe the fuel pump ground terminal, vehicle side, of the chassis harness fuel pump connector. Does the test lamp illuminate? | Go to Step 14 | Go to Step 16 |
10 | Repair the open in the battery feed circuit to the fuel pump relay harness connector terminal. Did you complete the repair? | Go to Step 18 | -- |
11 | Repair the open in the fuel pump relay ground circuit. Did you complete the repair? | Go to Step 18 | -- |
12 |
Did you find and correct the condition? | Go to Step 18 | Go to Step 17 |
13 | Replace the fuel pump relay. Did you complete the replacement? | Go to Step 18 | -- |
14 | Replace the fuel lift pump. Refer to Fuel Pump Replacement . Did you complete the replacement? | Go to Step 18 | -- |
15 | Test the supply voltage circuit of the fuel pump for an open or high resistance between the fuel pump relay and the fuel pump. Refer to Testing for Intermittent Conditions and Poor Connections or to Wiring Repairs in Wiring Systems. Is the action complete? | Go to Step 18 | -- |
16 | Repair the open in the fuel pump harness ground circuit. Did you complete the repair? | Go to Step 18 | -- |
17 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | Go to Step 18 | -- |
18 |
Does the engine start and continue to run? | Go to Step 19 | Go to Step 2 |
19 |
Are there any failed DTCs displayed? | System OK |