Operation CHARM: Car repair manuals for everyone.

Part 1






Signal too low. Permanent fault

EFI-621 Fuel tank pressure sensor, signal

Identification
First read Identifying cars constructed according to ORVR Application and ID.

Is the car constructed according to ORVR?

Yes - Safety

No - Signal too low. Permanent fault

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Signal too low. Permanent fault

EFI-621 Fuel tank pressure sensor, signal

Checking power cable








- 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 1 (engine control module (ECM) side) and ground.









The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

Checking power cable resistance








- Ignition off.
- Tank pressure sensor disconnected.
Connect an ohmmeter between fuel tank pressure sensor connector terminal 1 (engine control module (ECM) side) and ground.









The ohmmeter should read infinite resistance.

OK -

Not OK -

------------------------

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 1 (engine control module (ECM) side) and ground.









The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

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





Continue -

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Checking power cable 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 E4 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

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Checking for a short-circuit








- Check cable between fuel tank pressure sensor terminal 1 and connector E4 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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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 E4 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

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





Continue -

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








- Ignition off.
- Disassemble connector 24/2.
Connect an ohmmeter between connector 24/2 terminal C5 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

Checking for an open-circuit




- Check cable between connector 24/2 terminal C5 and connector 24/4 terminal E4 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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Checking control module connector












- Ignition off.
- Tank pressure sensor disconnected.
- Connector 24/4 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.
- Connect control module.
Connect an ohmmeter between connector 24/2 terminal C5 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

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





Continue -

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Checking for an open-circuit




- Check cable between connector 24/2 terminal C5 and engine control module (ECM) #B15 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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Checking power cables








- Ignition off.
- Disassemble connector 24/4.
Connect an ohmmeter between connector 24/4 terminal E4 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

Checking for a short-circuit








- Check cable between connector 24/4 terminal E4 and fuel tank pressure sensor terminal 1 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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Checking cable between 24/2 and 24/4








- Ignition off.
- Disassemble connector 24/2.
Connect an ohmmeter between connector 24/2 terminal C5 (engine control module (ECM) side) and ground.





The ohmmeter should read approximately 0.9 kohms.

OK -

Not OK -

------------------------

Checking for a short-circuit








- Check cable between connector 24/2 terminal C5 and connector 24/4 terminal E4 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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Fault-tracing information




- The fuel tank pressure sensor power cable is connected inside the engine control module (ECM) to the accelerometer and A/C pressure sensor power cables. If anything happens to any of these cables all three will be affected. In cars without A/C the A/C pressure sensor wiring is pre-routed. Always check cables to these components.
- Check cables between:
Connector 24/2 terminal C5 and control module #B15.
Accelerometer terminal 1 and engine control module (ECM) #B1.
Air conditioning (A/C) pressure sensor terminal 3 and engine control module (ECM) #B29.
for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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Checking the signal cable








- Ignition off.
- Tank pressure sensor disconnected.
- Ignition on.
Connect a voltmeter between tank pressure sensor connector terminal 3 (engine control module (ECM) side) and ground.









The voltmeter should read approximately 6 V.

OK -

Not OK -

------------------------

Checking signal cable resistance to ground








- Ignition off.
- Wait for approximately 150 seconds (cars with immobilizer 245 seconds).
- Tank pressure sensor disconnected.
Connect an ohmmeter between fuel tank pressure sensor connector terminal 3 (engine control module (ECM) side) and ground.









Does the ohmmeter read infinite resistance?

Yes -

No -

------------------------

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.
- Ignition on.
Connect a voltmeter between tank pressure sensor connector terminal 3 (engine control module (ECM) side) and ground.









The voltmeter should read approximately 6 V.

OK -

Not OK -

------------------------

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

Continue -

------------------------

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








- Tank pressure sensor disconnected.
- Disassemble connector 24/4.
- Ignition on.
Connect a voltmeter between connector 24/4 terminal E5 (engine control module (ECM) side) and ground.





The voltmeter should read approximately 6 V.

OK -

Not OK -

------------------------

Checking for an open-circuit








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

Continue -

------------------------

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.
- Ignition on.
Connect a voltmeter between connector 24/4 terminal E5 (engine control module (ECM) side) and ground.





The voltmeter should read approximately 6 V.

OK -

Not OK -

------------------------

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

Continue -

------------------------

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








- Disassemble connector 24/2.
- Ignition on.
Connect a voltmeter between connector 24/2 terminal C6 (engine control module (ECM) side) and ground.





The voltmeter should read approximately 6 V.

OK -

Not OK -

------------------------

Checking for an open-circuit








- Check cable between connector 24/2 terminal C6 and connector 24/4 terminal E5 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.

Continue -

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