Signal Too High. Permanent Fault
SIGNAL TOO HIGH. PERMANENT FAULT
Checking Power Cable
- Ignition OFF.
- Disconnect accelerometer.
- Ignition ON.
- Connect a voltmeter between accelerometer connector terminal 1 and ground.
The voltmeter should read 5 Volts.
If reading is OK:
- Proceed to Checking Ground Lead section below.
If value is Lower:
- Proceed to Checking Power Cable Resistance to Ground section below.
If value is Higher:
- Proceed to test step below.
Checking for a Short-Circuit
The accelerometer power cable is connected inside the engine control module (ECM) to the fuel tank pressure sensor, atmospheric pressure sensor and air conditioning (A/C) pressure sensor power cables. If anything happens to any of these cables all four will be affected. Air conditioning (A/C) pressure sensor wiring is prerouted, even on cars without one, and should always be checked.
Check Cables Between:
- Accelerometer terminal 1 and engine control module (ECM) #B1
- Air conditioning (A/C) pressure sensor terminal 3 and engine control module (ECM) #B29.
- Atmospheric pressure sensor terminal 1 and engine control module (ECM) #B29.
- Tank pressure sensor terminal 1 and engine control module (ECM) #B15 for a short-circuit to supply voltage.
- Then proceed to Verification section below.
Checking Ground Lead
- Ignition OFF.
- Accelerometer disconnected.
- Connect an ohmmeter between accelerometer connector terminal 2 and ground.
The ohmmeter should read approx. 0 Ohms.
If reading is OK:
- Proceed to Checking Signal Cable section below.
If reading is incorrect:
- Proceed to test step below.
Checking Engine Control Module Connector
- Ignition OFF.
- Accelerometer disconnected.
- Check engine control module (ECM) connector for contact resistance and oxidation and remedy.
- Engine control module (ECM) connected.
- Connect an ohmmeter between accelerometer connector terminal 2 and ground.
The ohmmeter should read approx. 0 Ohms.
If reading is OK:
- The diagnostic trouble code (DTC) has been caused by loose connections in the engine control module (ECM) connector.
- Then proceed to Verification section below.
If reading is incorrect:
- Check cable between accelerometer terminal 2 and engine control module (ECM) #B28 for an open-circuit.
- Then proceed to Verification section below.
Checking Signal Cable
- Ignition ON.
- Accelerometer disconnected.
- Connect a voltmeter between accelerometer connector terminal 3 and ground.
The voltmeter should read approx. 5 Volts.
If reading is OK:
- Proceed to Checking Accelerometer section below.
If value is Lower:
- Proceed to test step below.
If value is Higher:
- Check cable between accelerometer terminal 3 and engine control module (ECM) #B32 for a short-circuit to supply voltage.
- Then proceed to Verification section below.
Checking Engine Control Module Connector
- Ignition OFF.
- Accelerometer disconnected.
- Check engine control module (ECM) connector for contact resistance, oxidation and remedy.
- Engine control module (ECM) connected.
- Ignition ON.
- Connect a voltmeter between accelerometer connector terminal 3 and ground.
The voltmeter should read approx. 5 Volts.
If reading is OK:
- The diagnostic trouble code (DTC) has been caused by loose connections in the engine control module (ECM) connector.
- Then proceed to Verification section below.
If reading is incorrect:
- Check cable between accelerometer terminal 3 and engine control module (ECM) #B32 for an open-circuit.
- Then proceed to Verification section below.
Checking Accelerometer
- Ignition ON.
- Connect the accelerometer.
- START the engine and idle it.
- Read off diagnostic trouble codes (DTCs).
If EFI-444 is stored it should have intermittent fault status.
Alternative Intermittent:
- The cause of the diagnostic trouble code (DTC) has been loose connections in the accelerometer connector.
- Check connector for contact resistance, oxidation and remedy according to DDA5.
- Then proceed to Verification section below.
Alternative Permanent:
- Try a new accelerometer.
- Then proceed to Verification section below.
Checking Power Cable Resistance to Ground
- Ignition OFF.
- Accelerometer disconnected.
- Wait for approx. 150 seconds (cars with immobilizer 245 seconds).
- Connect an ohmmeter between accelerometer connector terminal 1 and ground.
The ohmmeter should read 0.2 - 1.5K Ohms.
If value is Lower:
- Proceed to Checking the Air Conditioning Pressure Sensor section below.
If value is Higher:
- Proceed to test step below.
Checking Engine Control Module Connector
- Ignition OFF.
- Accelerometer disconnected.
- Check engine control module (ECM) connector for contact resistance, oxidation and remedy.
- Engine control module (ECM) connected.
- Connect an ohmmeter between accelerometer connector terminal 1 and ground.
The ohmmeter should read approx. 0.2 - 1.5K Ohms.
If reading is OK:
- The diagnostic trouble code (DTC) has been caused by loose connections in the engine control module (ECM) connector.
- Then proceed to Verification section below.
If reading is incorrect:
- Check cable between accelerometer terminal 1 and engine control module (ECM) #B1 for an open-circuit.
- Then proceed to Verification section below.
Checking the Air Conditioning Pressure Sensor
- Ignition OFF.
- Accelerometer disconnected.
- Disconnect the air conditioning (A/C) pressure sensor.
- Connect an ohmmeter between accelerometer connector terminal 1 and ground.
The ohmmeter should read 0.2 - 1.5K Ohms.
If reading is OK:
- Try a new air conditioning (A/C) pressure sensor.
- Then proceed to Verification section below.
If reading is incorrect:
- Proceed to test step below.
Checking Fuel Tank Pressure Sensor
- Ignition OFF.
- Accelerometer disconnected.
- Air conditioning (A/C) pressure sensor disconnected.
- Disconnect tank pressure sensor.
- Connect an ohmmeter between accelerometer connector terminal 1 and ground.
The ohmmeter should read 0.2 - 1.5K Ohms.
If reading is OK:
- Try a new tank pressure sensor.
- Then proceed to Verification section below.
If reading is incorrect:
- Proceed to Checking Atmospheric Pressure Sensor section below.
Checking Atmospheric Pressure Sensor
- Ignition OFF.
- Accelerometer disconnected.
- Air conditioning (A/C) pressure sensor disconnected.
- Fuel tank pressure sensor disconnected.
- Disconnect atmospheric pressure sensor.
- Connect an ohmmeter between accelerometer connector terminal 1 and ground.
The ohmmeter should read 0.2 - 1.5K Ohms.
If reading is OK:
- Try a new atmospheric pressure sensor.
- Then proceed to Verification section below.
If reading is incorrect:
- Proceed to test step below.
Checking for a Short-Circuit
The accelerometer power cable is connected inside the engine control module (ECM) to the fuel tank pressure sensor, atmospheric pressure sensor and air conditioning (A/C) pressure sensor power cables. If anything happens to any of these cables all four will be affected. Air conditioning (A/C) pressure sensor wiring is prerouted, even on cars without one, and should always be checked.
Check cables between:
- Accelerometer terminal 1 and engine control module (ECM) #B1
- Air conditioning (A/C) pressure sensor terminal 3 and engine control module (ECM) #B29
- Atmospheric pressure sensor terminal 1 and engine control module (ECM) #B29
- Tank pressure sensor terminal 1 and engine control module (ECM) #B15.
For a short-circuit to ground.
- Then proceed to Verification section below.
Verification
Hint: After carrying out the repair, check that the fault has been remedied as follows:
- Ignition OFF.
- Accelerometer, air conditioning (A/C) pressure sensor and fuel tank pressure sensor connected.
- START the engine and idle it.
- Go into scrolling values list.
- Read off accelerometer signal.
The value should be approx. 2.5 Volts.
It reading is OK:
- Fault corrected.
If reading is Incorrect:
- Proceed to test step below.
Fault-Tracing Information
- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?
Yes:
- Fault not corrected.
No:
- Return to Checking Power Cable section at top.