Part 1

Signal too high. Permanent fault

EFI-621 Fuel tank pressure sensor, signal

Checking ground lead








- Ignition off.
- Wait for approximately 150 seconds (cars with immobilizer 245 seconds).
- Disconnect tank pressure sensor.
Connect an ohmmeter between fuel tank pressure sensor connector terminal 2 (engine control module (ECM) side) and ground.









The ohmmeter should read approximately 0 ohms.

OK - Checking the signal cable

Not OK - Checking connector 24/4

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Checking connector 24/4








- Ignition off.
- Tank pressure sensor disconnected.
- Check connector 24/4 for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Assemble connector 24/4.
Connect an ohmmeter between fuel tank pressure sensor connector terminal 2 (engine control module (ECM) side) and ground.









The ohmmeter should read approximately 0 ohms.

OK - Fault-tracing information

Not OK - Checking ground lead between connector 24/4 and fuel tank pressure sensor

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Fault-tracing information
- The diagnostic trouble code (DTC) has been caused by loose connections in connector 24/4.





Continue - Verification

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Checking ground lead between connector 24/4 and fuel tank pressure sensor








- Ignition off.
- Tank pressure sensor disconnected.
- Disassemble connector 24/4.
Connect an ohmmeter between connector 24/4 terminal E6 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0 ohms.

OK - Checking for an open-circuit

Not OK - Checking connector 24/2

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Checking for an open-circuit








- Check cable between fuel tank pressure sensor terminal 2 and connector 24/4 terminal C6 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

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Checking connector 24/2








- Ignition off.
- Tank pressure sensor disconnected.
- Connector 24/4 disassembled.
- Check connector 24/2 for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Assemble connector 24/2.
Connect an ohmmeter between connector 24/4 terminal E6 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0 ohms.

OK - Fault-tracing information

Not OK - Checking ground lead between connectors 24/2 and 24/4

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Fault-tracing information
- The diagnostic trouble code (DTC) has been caused by loose connections in connector 24/2.





Continue - Verification

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Checking ground lead between connectors 24/2 and 24/4








- Ignition off.
- Tank pressure sensor disconnected.
- Assemble connector 24/4.
- Separate connector 24/2.
Connect an ohmmeter between connector 24/4 terminal C7 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0 ohms.

OK - Checking for an open-circuit

Not OK - Checking control module connector

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Checking for an open-circuit








- Check cable between connector 24/2 terminal C7 and connector 24/4 terminal C6 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

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Checking control module connector












- Ignition off.
- Tank pressure sensor disconnected.
- Connector 24/2 disassembled.
- Check control module connector for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- Control module connected.
Connect an ohmmeter between connector 24/2 terminal C7 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0 ohms.

OK - Fault-tracing information

Not OK - Checking for an open-circuit

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Fault-tracing information
- The cause of the diagnostic trouble code (DTC) has been loose connections in the control module connector.

Continue - Verification

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Checking for an open-circuit




- Check cable between connector 24/2 terminal C7 and engine control module (ECM) for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

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Checking the signal cable








- Ignition on.
- Tank pressure sensor disconnected.
Connect a voltmeter between fuel tank pressure sensor connector terminal 3 and ground.









The voltmeter should read approximately 5 V.

OK - Checking fuel tank pressure sensor

Low - Checking connector 24/4

High - Checking signal cable between connector 24/4 and fuel tank pressure sensor

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Checking signal cable between connector 24/4 and fuel tank pressure sensor








- Ignition on.
- Tank pressure sensor disconnected.
- Disassemble connector 24/4.
Connect a voltmeter between connector 24/4 terminal E5 and ground.









The voltmeter should read approximately 5 V.

OK - Checking for a short-circuit

Not OK - Checking signal cable between connector 24/4 and 24/2

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Checking for a short-circuit








- Check cable between fuel tank pressure sensor terminal 3 and connector 24/4 terminal E5 for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue - Verification

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Checking signal cable between connector 24/4 and 24/2








- Ignition on.
- Tank pressure sensor disconnected.
- Assemble connector 24/4.
- Disassemble connector 24/2.
Connect a voltmeter between connector 24/2 terminal C6 and ground.





The voltmeter should read approximately 5 V.

OK - Checking for a short-circuit

Not OK - Checking for a short-circuit

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