DTC P0462: FUEL LEVEL SENDING UNIT VOLTS TOO LOW Dodge Ram Van B2500

Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see RAM VAN & RAM WAGON wiring diagram in WIRING DIAGRAMS article.

Note. DTC P0462: FUEL LEVEL SENDING UNIT VOLTS TOO LOW is monitored with ignition on and with battery voltage more than 10.4 volts. DTC may be stored in Powertrain Control Module (PCM) when PCM senses fuel level sensor signal less than .4 volt for 2 seconds. Possible causes are: defective fuel level sensor, defective PCM, defective connector or defective wiring.

1. Turn ignition on, with engine off. Using scan tool, read FUEL LEVEL SENDING UNIT voltage. If voltage is less than .4 volt, go to next step. If voltage is .4 volt or more, go to step 8).
2. Turn ignition off. Disconnect fuel pump module connector. Fuel pump module is located in fuel tank. Clean and/or repair connector as necessary. Turn ignition on, with engine off. Using scan tool, read FUEL LEVEL SENDING UNIT voltage. If voltage is more than 9 volts, go to next step. If voltage is 9 volts or less, go to step 5). NOTE: Fuel tank must be lowered to remove fuel pump module. Partially draining fuel tank may be necessary prior to removal. Fuel system may be under high pressure. Release fuel pressure prior to opening fuel system.
3. Turn ignition off. Ensure fuel pump module connector is still disconnected. Remove fuel pump module. Position fuel gauge float in down (empty) position. Using an ohmmeter, check resistance between low fuel sensor circuit (Light Blue/Black wire) and sensor ground circuit (Black/Light Blue wire). If resistance is not 210-230 ohms, go to next step. If resistance is 210-230 ohms, replace fuel pump module wiring harness. Perform TEST VER-2A.
4. At this time, fuel level sensor is assumed defective. Replace fuel level sensor. Perform TEST VER-2A.
5. Turn ignition off. Ensure fuel pump module connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance between ground and PCM connector, fuel level sensor signal circuit (Light Blue/Black wire). If resistance is less than 5 ohms, repair fuel level sensor circuit for short to ground. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
6. Ensure ignition is off. Ensure fuel pump module and PCM connectors are still disconnected. Using ohmmeter, check resistance between PCM connector, fuel level sensor signal circuit (Light Blue/Black wire) and sensor ground circuit (Black/Light Blue wire). If resistance is less than 5 ohms, repair fuel level sensor signal circuit for short to sensor ground circuit. Perform TEST VER-2A. If resistance is 5 ohms or more, go to next step.
7. At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-2A.
8. Turn ignition on, with engine off. Using scan tool, monitor FUEL LEVEL SENDING UNIT voltage while wiggling fuel pump module connector and wiring harness. If voltage changes while wiggling wiring harness, repair wiring harness where wiggling caused voltage to change. Perform TEST VER-2A. If voltage does not change while wiggling wiring harness, go to next step.
9. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. Perform TEST VER-2A. If connectors and wiring harness are okay, test is complete.