Signal Too High - Permanent Fault

ECM-4020 FUEL TANK PRESSURE SENSOR
SIGNAL TOO HIGH - PERMANENT FAULT

Checking the connector



- Ignition off
- Check the fuel tank pressure sensor connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Permanent Fault Also check for loose connections according to [1][2]Checking Wiring and Terminals. Intermittent Faults Check for damage carefully.
- Assemble the connector
- Start the engine

Read the fuel tank pressure.
The fuel tank pressure should be approximately 0 hPa when the fuel tank filler cap is open

Other information
- For specifications, Specifications
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T

Is the fuel tank pressure ok?
Yes - Testing Complete.
No - Continue below.


Checking the connector



Check the ground lead between control module terminal B4 (# B14) and fuel tank pressure sensor connector terminal 1. Check the ground lead between control module terminal B31 (# B41) and fuel tank pressure sensor connector terminal 2 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check the power supply cable between control module terminal B10 (# B20) and fuel tank pressure sensor connector terminal 3 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault

Check the signal cable between control module terminal B31 (# B41) and fuel tank pressure sensor connector terminal 2 for a short-circuit to supply voltage according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: Use a test screwdriver with at least a 3W bulb to determine if the cable is short-circuited to supply voltage

Other information
- Connecting the breakout box/accessing the control module, Connecting the Breakout Box (ECM)
- For information about signals, see Diagnostic Parameters and Pinout Values. Signal Description, ME7, B5XX4T


Verification



Hint: After carrying out the repair, check that the fault has been remedied.

- Ignition off.
- Reconnect connectors, reinstall components.
- Start the engine.

Read fuel tank pressure.
The fuel tank pressure should be approximately 0 hPa (0 psi) when the fuel tank filler cap is open.

Is the fuel tank pressure ok?
Yes - Testing Complete.
No - Continue below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault tracing for this diagnostic trouble code (DTC) or make another attempt.