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 test step below.

If value is lower:
^ Proceed to Checking Power Cable Resistance To Ground section below.

If value is higher:
^ The accelerometer power cable is connected inside the engine control module (ECM) to the tank pressure sensor and A/C pressure sensor power cables. If anything happens to any of these cables all three will be affected. A/C pressure sensor wiring is prerouted, even on cars without one, and should always be checked. Check wiring between: Accelerometer terminal 1 and engine control module # B1, A/C pressure sensor terminal 3 and engine control module # B29, tank pressure sensor terminal 1 and engine control module # 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 The Engine Control Module Connector
- Ignition off.
- Accelerometer disconnected.
- Check engine control module connector for contact resistance and oxidation.
- Engine control module 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) was caused by poor contact in the engine control module connector.
^ Proceed to Verification section below.

If reading is incorrect:
^ Check cable between accelerometer terminal 2 and engine control module # 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 # B32 for a short-circuit to supply voltage.
^ Then proceed to Verification section below.





Checking The Engine Control Module Connector
- Ignition off.
- Accelerometer disconnected.
- Check engine control module connector for contact resistance and oxidation.
- Engine control module 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 was caused by poor contact in the engine control module connector.
^ Then proceed to Verification section below.

If reading is incorrect:
^ Check cable between accelerometer terminal 3 and engine control module # B32 for an open-circuit.
^ Then proceed to Verification section below.





Checking Accelerometer
- Ignition on.
- Connect the accelerometer.
- Erase diagnostic trouble code.
- Start the engine and idle it.
- Does the diagnostic trouble code recur?

Yes:
^ Try a new accelerometer.
^ Then proceed to Verification section below.

No:
^ The cause of the diagnostic trouble code is poor contact in the accelerometer connector. Check connector for contact resistance, oxidation and remedy.
^ 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.
- Does the ohmmeter read approx. 0 ohms.

Yes:
^ Proceed to Checking For Short-circuit To Ground section below.

No:
^ Proceed to test step below.





Checking The Engine Control Module Connector
- Ignition off.
- Accelerometer disconnected.
- Check engine control module connector for contact resistance and oxidation.
- Engine control module 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 was caused by poor contact in the engine control module connector.
^ Then proceed to Verification section below.

If reading is incorrect:
^ Check cable between accelerometer terminal 1 and engine control module # B1 for an open-circuit.
^ Then proceed to Verification section below.





Checking The A/C Pressure Sensor
- Ignition off.
- Accelerometer disconnected.
- Disconnect the 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 A/C pressure sensor.
^ Then proceed to Verification section below.

If reading is incorrect:
^ Proceed to test step below.





Checking Tank Pressure Sensor
- Ignition off.
- Accelerometer disconnected.
- Any 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 test step below.





Checking For Short-circuit To Ground
- The accelerometer power cable is connected inside the engine control module to the tank pressure sensor and A/C pressure sensor power cables. If anything happens to any of these cables all three will be affected. A/C pressure sensor wiring is prerouted, even on cars without one, and should always be checked.

Check Wiring Between:
- Accelerometer terminal 1 and engine control module # B1.
- A/C pressure sensor terminal 3 and engine control module # B29.
- Tank pressure sensor terminal 1 and engine control module # B15 for a short-circuit to ground.

^ Then proceed to Verification section below.





Verification
- After carrying out the repair, check that the fault has been remedied as follows.
- Ignition off.
- Accelerometer and any A/C pressure sensor and tank pressure sensor connected.
- Start the engine and idle it.
- Go into scrolling values list.
- Read off accelerometer voltage signal.
- The reading should be about 2.5 Volts.

If 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 above