Circuit Description
The PCM supplies 5 volts to the fuel level sensor circuit. The fuel level sensor varies the voltage relative to the amount of fuel in the tank. The PCM monitors the voltage on the fuel level circuit to calculate the amount of fuel in the tank. The PCM uses the fuel level sensor information to control the fuel gauge via the fuel level output control circuit.
The PCM also uses fuel level information to enable the enhanced evaporative emission diagnostic.
Diagnostic Aids
Check for Poor connections or damaged harness. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal to wire connection and damaged harness.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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Normally, ignition feed voltage should be present on the output control circuit with the PCM disconnected and the ignition turned ON.
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Checks for a shorted component or a short to B+ on the output control circuit. Either condition would result in a measured current of over 1.5 amps. Also checks for a component that is going open while being operated, resulting in a measured current of 0 amps.
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Checks for a malfunctioning instrument cluster.
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This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you peform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | ||
2 | Was the Instrument Cluster System Check performed? | -- | ||
Is voltage near the specified value? | B+ | |||
Does the current reading remain between the specified values? | 0.05 Amp-1.5 Amps | |||
Is voltage at the specified value? | 0V | |||
6 | Locate and repair the short to voltage in the affected PCM output circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
7 | Check the ignition feed fuse for the instrument panel cluster. Is the the fuse blown? | -- | ||
8 |
Did you complete the repair? | -- | -- | |
9 |
Is voltage near the specified value? | B+ | ||
10 |
Was a problem found? | -- | ||
11 |
Was a problem found? | -- | ||
12 |
Does the fuel gauge indicate EMPTY? | -- | Go to Diagnostic Aids | |
13 |
Was a problem found? | -- | ||
14 | Locate and repair open in the ignition feed circuit to the instrument panel cluster indicator lamps. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |
15 | Replace the instrument panel cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console. Did you complete the repair? | -- | -- | |
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Important: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the repair? | -- | -- | ||
17 | Operate the affected lamp using the scan tool output tests function. Does the affected lamp operate properly? | -- | System OK |
