PleasureCraft Engine Group 5.0L, Diagnostic Manual

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5.0/5.7/6.0/8.1L Diagnosis 5 - 137
MEFI 4 - PCM
DTC 81 - Fuel Pump Relay Driver Circuit High, Low or Open
Step Action Value Yes No
1
Was the “On-Board Diagnostic” (OBD) system check Go to OBD
performed? — Go to Step 2 System Check
1. Turn ON the ignition, with the engine OFF.
2
2. Command the relay ON and OFF using a scan tool, or
cycle the ignition switch “OFF” and then “ON.”
Does the relay turn ON and OFF when commanded? — Go to Step 3 Go to Step 5
1. Turn OFF the ignition.
2. Disconnect the ECM connector J1.
3. Install a 5 amp fused jumper wire from a known good
ground to the control circuit at the ECM harness
connector (J1-6).
4. Turn ON the ignition, with the engine OFF.
3
Important: Replace the relay if the DMM goes to 0 during
the current draw test.
5. Using a DMM on 40 amp scale, measure the current
from the relay control circuit in the ECM harness
connector to ground for 2 minutes.
Does the current draw measure less than the specifi ed Go to
value? 0.75 A Diagnostic Aids Go to Step 4
1. Turn OFF the ignition.
2. Disconnect the fuel pump relay connector.
4
3. Using a DMM, measure the resistance from the relay
control circuit in the ECM harness connector to ground.
Does the DMM display infi nite resistance or OL (out-of-limits)? — Go to Step 12 Go to Step 10
1. Turn OFF the engine.
2. Disconnect the fuel pump relay connector.
3. Connect a test lamp between the fuel pump relay
harness connector terminal “85” and the fuel pump relay
5
harness connector terminal “86.”
4. Turn ON the ignition, with the engine OFF.
5. Using a scan tool, command the relay ON and OFF, or
cycle the ignition switch “OFF” and then “ON.”
Does the test lamp turn ON and OFF when commanded? — Go to Step 8 Go to Step 6
1. Turn ON the ignition, with the engine OFF.
2. Using a test lamp connected to ground, probe the fuel
6
pump relay harness connector terminal “86.”
Is the test lamp illuminated? — Go to Step 7 Go to Step 11
1. Turn OFF the ignition.
2. Reconnect the relay.
3. Disconnect the ECM connector J1.
4. Turn ON the ignition, with the engine OFF.
7
5. Using a fused jumper wire connected to ground,
momentarily probe ECM harness connector terminal
“J1-6.”
Does the relay turn ON when the circuit is grounded and
OFF when the circuit is opened? — Go to Step 9 Go to Step 10