Signal Too High

Other Diagnostic Trouble Codes
- Read off OTHER DTCs in the engine management system.
- Is Motronic 4.4 engine control module (ECM) diagnostic trouble code (DTC) EFI-411 stored?

Yes:
- Proceed to: Fault-tracing Information section below.

No:
- Proceed to: Status Message section below.





Fault-tracing Information
- Fault-trace according to Motronic 4.4 engine management system diagnostic trouble code.
- Fault corrected.

Status Message

NOTE: To get the correct status message carry out the following before reading the diagnostic trouble code:

- Ignition ON.
- Depress accelerator pedal (AP) completely. Keep it depressed.
- Wait for about 15 seconds.
- Read out the diagnostic trouble code.
- Does the status indicate PERMANENT FAULT?

Yes:
- Proceed to: Checking Throttle Position Sensor Signal section below.

No:
- Proceed to: Intermittent Fault section below.





Checking Throttle Position Sensor Signal
- Ignition ON.
- Go into scrolling values.
- Read off the throttle position (TP) sensor signal.
- Fully depress the accelerator pedal several times and check that the throttle position sensor signal increases to above approx. 5 Volts.
- Does the value increase to approx. 5 Volts?

Yes:
- Proceed to: Checking Voltage Drop Over The Engine Control Module Signal Ground section below.

No:
- Proceed to: Connecting The Test Box section below.





Connecting The Test Box
- Ignition OFF.
- Wait for about 150 seconds.
- Connect a test box to the automatic transmission control module (TCM) and check ground terminals. Check the power ground carefully.
- Proceed to: Checking Signal Cable For Short-circuit To Supply Voltage section below.





Checking Signal Cable For Short-circuit To Supply Voltage
- Ignition OFF.
- Connect the transmission control module.
- Disconnect the engine control module.
- Ignition ON.
- Connect a voltmeter between # 7 and # 15 on the test box.
- The voltmeter should read approx. 0 Volts.

If reading is OK:
- Proceed to: Checking Throttle Position Sensor Circuit section below.

If reading is incorrect:
- Proceed to: Checking For A Short-circuit section below.

Checking Throttle Position Sensor Circuit
- Check throttle position sensor circuit, diagnostic trouble code EFI-411. Throttle position sensor signal, permanent fault, signal too high.
- Proceed to: Verification section below.





Checking For A Short-circuit
- Check cable between transmission control module # 7 and Motronic 4.4 engine control module # B20 for a short-circuit to supply voltage.
- Proceed to: Verification section below.





Checking Voltage Drop Over The Engine Control Module Signal Ground
- Ignition OFF.
- Connect a test box to engine control module.
- Control modules connected.
- Ignition ON.
- Turn on as many power consuming items as possible.
- Connect a voltmeter between # 42 (# A42) on the test box and ground terminal 31/33. Note the voltmeter reading.
- Proceed to: Connecting The Test Box section below.





Connecting The Test Box
- Ignition OFF.
- Disconnect the test box from the engine control module.
- Connect test box to the transmission control module.
- Proceed to: Checking Voltage Drop Over The Transmission Control Module Signal Ground section below.





Checking Voltage Drop Over The Transmission Control Module Signal Ground
- Ignition OFF.
- Connect the control modules.
- Ignition ON.
- Turn on as many power consuming items as possible.
- Connect a voltmeter between # 15 on the test box and ground terminal 31/53. Note the reading. Add the previous reading to the new reading.
- When added together the sum of the two readings should not be more than 0.1 Volts.

If reading is OK:
- Proceed to: Checking Voltage Drop Over Signal Ground And Power Ground section below.

If reading is incorrect:
- Proceed to: Checking For Contact Resistance And Oxidation section below.





Checking For Contact Resistance And Oxidation
- Ignition OFF.
- Check ground terminal 31/53 and transmission control module connectors for contact resistance and oxidation.
- Proceed to: Verification section below.





Checking Voltage Drop Over Signal Ground And Power Ground
- Ignition ON.
- Turn on as many power consuming items as possible.
- Connect a voltmeter between # 7 and # 15 on the test box.
- The voltmeter should read less than 0.6 Volts.

If reading is OK:
- Proceed to: Checking Throttle Position Sensor Circuit section below.

If reading is incorrect:
- Proceed to: Checking For Contact Resistance And Oxidation section below.

Checking Throttle Position Sensor Circuit
- Check throttle position sensor circuit, diagnostic trouble code EFI-411. Throttle position sensor signal, permanent fault, signal too high.
- Proceed to: Verification section below.





Checking For Contact Resistance And Oxidation
- Ignition OFF.
- Check ground terminals 31/53 and 31/66, the cables between the ground terminals and transmission control module # 1 and # 15, and the transmission control module connector for contact resistance and oxidation.
- Proceed to: Verification section below.





Verification
- After repairs have been completed they must be verified as follows to ensure the fault has been eliminated:

- Ignition OFF.
- Reconnect the connectors, reinstall components etc.
- Ignition ON.
- Push down the accelerator pedal to wide open throttle and keep it fully depressed.
- Wait approx. 15 seconds.

- Read off the status of the Diagnostic trouble code. Does the status indicate INTERMITTENT FAULT?

Yes:
- Fault corrected.

No:
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
The verification result shows that the fault persists.

- Do you want to exit fault-tracing?

Yes:
- Fault not corrected.

No:
- Proceed to: Other Diagnostic Trouble Codes section above.





Intermittent Fault
- Check cable between transmission control module # 7 and engine control module # B20 for an intermittent short-circuit to supply voltage.
- Check throttle position sensor circuit, diagnostic trouble code EFI-411 Throttle position sensor signal, signal too high.
- Proceed to: Fault-tracing Information section below.

Fault-tracing Information
For intermittent faults fault-tracing is not followed by a verification because the fault is not present at this moment.

- Do you want to repeat fault-tracing?

Yes:
- Proceed to: Other Diagnostic Trouble Codes section above.

No:
- Operation done.