DTC P0642:00 [MZI-3.7]

id0102d2315500

DTC P0642:00 | Sensor reference voltage circuit low
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DETECTION CONDITION | • Indicates the reference voltage circuit is lower than reference voltage minimum.
POSSIBLE CAUSE | • Fuel tank pressure sensor connector or terminal malfunction • PCM connector or terminal malfunction • Short to ground between fuel tank pressure sensor terminal A and PCM terminal 1D • Fuel tank pressure sensor malfunction • PCM malfunction

Diagnostic procedure

STEP | INSPECTION | ACTION
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1 | VERIFY FREEZE FRAME DATA HAS BEEN RECORDED • Has FREEZE FRAME DATA been recorded? | Yes | Go to the next step.
No | Record FREEZE FRAME DATA on the repair order, then go to the next step.
2 | VERIFY RELATED SERVICE INFORMATION AVAILABILITY • Verify related Service Information availability. • Is any related Service Information available? | Yes | Perform repair or diagnosis according to the available Service Information. • If the vehicle is not repaired, go to the next step.
No | Go to the next step.
3 | INSPECT FUEL TANK PRESSURE SENSOR CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the fuel tank pressure sensor connector. • Inspect for poor connection (such as damaged/pulled-out pins, corrosion). • Are there any malfunction? | Yes | Repair or replace suspected part, then go to Step 7.
No | Go to the next step.
4 | INSPECT PCM CONNECTOR FOR POOR CONNECTION • Turn the ignition switch off. • Disconnect the PCM connector. • Inspect for poor connection (such as damaged/ pulled-out pins, corrosion). • Are there any malfunction? | Yes | Repair or replace suspected part, then go to Step 7.
No | Go to the next step.
5 | INSPECT FUEL TANK PRESSURE SENSOR CIRCUIT FOR SHORT TO GROUND • Fuel tank pressure and PCM connectors are disconnected. • Turn the ignition switch off. • Inspect the continuity between fuel tank pressure sensor terminal A (wiring harness-side) and body ground. • Is there continuity? | Yes | Repair or replace suspected part, then go to Step 7.
No | Go to the next step.
6 | INSPECT FUEL TANK PRESSURE SENSOR • Inspect the fuel tank pressure sensor. (See FUEL TANK PRESSURE SENSOR INSPECTION [MZI-3.7].) • Is there any malfunction? | Yes | Replace the evaporative hose component, then go to the next step. (See FUEL TANK REMOVAL/INSTALLATION [MZI-3.7].)
No | Go to the next step.
7 | VERIFY TROUBLESHOOTING OF DTC P0642:00 HAS BEEN COMPLETED • Verify that all disconnected connectors reconnected. • Clear the DTC from the PCM memory using the M-MDS. • Perform the KOEO or KOER self-test. (See KOEO/KOER SELF TEST [MZI-3.7].) • Is the PENDING CODE for the DTC present? | Yes | Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZI-3.7].) Go to the next step.
No | Go to the next step.
8 | VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [MZI-3.7].) • Are any DTCs present? | Yes | Go to the applicable DTC inspection. (See DTC TABLE [MZI-3.7].)
No | Troubleshooting completed.