Circuit Description
The powertrain control module (PCM) uses the fuel level input in order to calculate the expected vapor pressures within the fuel system. These vapor pressures vary as the fuel level changes. The vapor pressure is critical in determining if the Evaporative Emissions system is operating properly. The PCM also uses the fuel level in order to determine if the fuel level is too high or too low to be able to accurately detect EVAP system malfunction.
Conditions for Setting the DTC
Fuel level hasn't changed more than 1.6% in 120 miles.
Action Taken When the DTC Sets
| • | The PCM will record the operating conditions during the time which the diagnostic fails. This information will store in the Failure Records buffer. |
| • | A history DTC stores. |
| • | The fuel level will default to 40 percent. |
Conditions for Clearing the DTC
| • | A History DTC clears after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Diagnostic Aids
| • | An intermittent problem may be caused by the following conditions: |
| - | Poor electrical connection |
| - | Rubbed through wire insulation |
| - | A wire that is broken inside the wire insulation |
| • | Any circuitry, that is suspected as causing the intermittent complaint, should be thoroughly checked for the following conditions: |
| - | Backed out terminals |
| - | Improper mating |
| - | Broken locks |
| - | Improperly formed or damaged terminals |
| - | Poor terminal to wire connection |
Test Description
Numbers below refer to the step numbers on the Diagnostic Table.
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The Powertrain OBD System Check prompts the technician to complete some basic checks and store the Freeze Frame Data and the Failure records on the scan tool if applicable. This creates an electronic copy of the data taken when the malfunction occurred. This information on the scan tool can be referred to later.
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Replacement PCMs must be reprogrammed and the crankshaft position system variation procedure must be performed. Refer to the latest Techline information for programming procedures and also refer to the Crankshaft Position System Variation Learn .
Before replacing the PCM, check the PCM electrical connector terminals for the following conditions:
| • | Improper mating |
| • | Broken locks |
| • | Physical damage to the wiring harness |
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | |||||||
2 |
Are DTC P0462 or P0463 set? | -- | Go to DTC P0462 Fuel Level Sensor Circuit Low Voltage or | |||||
3 |
Does scan tool indicate specified level? | 100% | ||||||
4 | Connect a jumper wire between the following circuits:
Does the scan tool display specified value? | 0% | ||||||
5 |
Was a repair necessary? | -- | ||||||
6 |
Does the test light illuminate? | -- | ||||||
7 |
Was a repair necessary? | -- | ||||||
8 |
Was a repair necessary? | |||||||
Is the action complete? | -- | -- | ||||||
10 |
Was a repair necessary? | -- | ||||||
11 |
Is the action complete? | -- | -- | |||||
12 |
Does the scan tool indicate that this diagnostic ran and passed? | -- | ||||||
13 | Check if any additional DTCs are set. Are any DTCs displayed that have not been diagnosed? | -- | Go to Applicable DTC Table | System OK |
