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Home >> Volvo >> 1998 >> V70 AWD L5-2.4L Turbo VIN 56 B5254T >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> Manufacturer Code Charts >> AT / DTC Codes (Transmission Control Module) >> AT-223 Throttle Position Sensor >> Signal Too Low

Signal Too Low






SPECIAL TOOLS
Test box tool No. 981 3190, or equivalent
Volvo scan tool No. 998 8686, or equivalent

WEAK SIGNAL
1. Other Diagnostic Trouble Codes (DTCs)
- Read off OTHER DTCs in the engine management system (Engine Control Modules (ECM))
- Are any of the these DTCs set
EFI-243 for Fenix 5.2,
EFI-411 for LH 3.2,
EFI-411 for Motronic 4.3
EFI-411 for Motronic 4.4?
- YES: Proceed to step 2
- NO: Proceed to step 3
2. Fault-tracing information
- Carry out fault-tracing in accordance with the diagnostic trouble code for the engine management system, refer to Powertrain Management
- Then continue with step 22





3. Status message

NOTE: To get the correct status message the ignition must be ON for approximately 15 seconds before reading out the DTC.

- Read out the DTC
- Does the status indicate PERMANENT FAULT?
YES: Proceed to step 4
NO: Proceed to step 24





4. Checking the Throttle Position (TP) sensor signal
- Preparation:
Ignition ON
Select scrolling values.
Read off the throttle position sensor sensor signal.
- Press Accelerator Pedal (AP) to floor and check if the throttle position sensor sensor signal increases.
- Did the value increase?
YES: Proceed to step 13
NO: Proceed to step 5





5. Checking signal wiring resistance to ground
- Preparation:
Ignition OFF
Connect a test box to the ECM, refer to Powertrain Management.
ECM disconnected (both control modules on models with MFI LH 3.2 and EZ129K).
Disconnect the Transmission Control Module (TCM).
- Connect an ohmmeter between ground and the test box:
#50 (#B20) for LH 3.2 MFI ECM.
#20 (#B20) for Fenix 5.2, Motronic 4.3 and Motronic 4.4.
- The ohmmeter should indicate approx. 0 Ohms
- If reading is OK:
Proceed to step 7
- If reading is incorrect:
Proceed to step 6





6. Checking for short-circuit
- Check the cable between the TCM #B20 and the ECM #B20 for short-circuit to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- On cars with ECM type LH 3.2/EZ129K, also check the cable between ECM LH 3.2 #B20 and EZ129K #B20 for short-circuits to ground according to step 3 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22





7. Checking signal from engine control module
- Preparation:
Ignition off
Connect the ECM
Ignition ON
- Connect an voltmeter between ground and the test box:
#50 (#B20) for LH 3.2 MFI ECM.
#20 (#B20) for Fenix 5.2, Motronic 4.3 and Motronic 4.4.
- The voltmeter should normally indicate approx. 0.5 volt at closed throttle position .
- The voltage should not drop below 0.1 volt at closed throttle position.
- Is reading is OK?
YES: Proceed to step 9
NO: Proceed to step 8
8. Checking throttle position sensor circuit
- Check the throttle position sensor circuit according to the relevant information for the ECM installed, refer to Powertrain Management
Fenix 5.2:
DTC 2-4-3:
Throttle position signal, permanent
LH 3.2, EZ1 29K MFI control module:
DTC 4-1-1:
Throttle position sensor signal, permanent fault, signal too low
Motronic 4.3:
DTC 4-1-1:
Throttle position sensor signal, permanent fault, signal too low
Motronic 4.4:
DTC EFI-411:
Throttle position sensor signal, permanent fault, signal too low
- Then continue with step 22





9. Connecting the Test box
- Preparation:
Ignition OFF
- Connect test box to the TCM and check ground points. Connecting the Test Box
- Then continue with step 10





10. Checking signal to the transmission control module (TCM)
- Preparation:
Ignition OFF
ECM connected.
Ignition ON
- Connect a voltmeter between #50 (#B20) and #20 (#A20) on the test box.
- The voltmeter should normally read approx. 0.5 volts at closed throttle position.
- The voltage must not drop below 0.1 volt at closed throttle position.
- Is reading is OK?
YES: Proceed to step 11
NO: Proceed to step 12





11. Checking for oxidation and resistance in contacts
- Preparation:
Ignition OFF
- The DTC was set because of poor contact in the control modules' connectors.
- Check and correct the control modules' connectors for contact resistance and oxidation according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22





12. Checking for open-circuit
- Check the cable between the TCM #B20 and the ECM #B20 for Fenix 5.2, LH 3.2x, Motronic 4.3 or Motronic 4.4, for break in circuit according to step 2 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22





13. Checking voltage drop over signal ground for the ECM
- Preparation:
Ignition OFF
Connect a test box to the ECM (MFI Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4), refer to Powertrain Management.
Control module connected.
Ignition ON
Turn on as many power consuming items as possible.
- Connect a voltmeter between ground points 31/33 and the test box:
Fenix 5.2:
#42 (#A42) signal ground
LH 3.2, EZ1 29K MFI control module
#20 (#A20) signal ground
Motronic 4.3:
#42 (#A42) signal ground
Motronic 4.4
#42 (#A42) signal ground
- Note the reading on the voltmeter.
- Then continue with step 14





14. Connecting the Test box
- Preparation:
Ignition OFF
Disconnect from the ECM
- Connect test box to the TCM. Connecting the Test Box
- Then continue with step 15





15. Checking voltage drop over signal ground for the TCM
- Preparation:
Ignition OFF
Connect the control modules
Ignition ON
Turn on as many power consuming items as possible.
- Connect a voltmeter between ground point 31/33 and #20 (#A20) on the test box.
- Make a note of the reading.
- Add the previous reading obtained to the new reading.
- When added together the sum of the two readings should not be more than 0.1 volt
- If reading is OK:
Proceed to step 17
- If reading is incorrect:
Proceed to step 16





16. B16Checking for oxidation and resistance in contacts
- Preparation:
Ignition OFF
- Check ground point 31/33 and the TCM connectors for contact resistance and oxidation according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22





17. Checking voltage drop over signal ground and power ground
- Preparation:
Ignition ON
Turn on as many power consuming items as possible.
- Connect a voltmeter to between #20 (#A20) and #29 (#A29) on the test box.
- The voltmeter should read less than 0.6 volts
- If reading is OK:
Proceed to step 19
- If reading is incorrect:
Proceed to step 18





18. Checking for oxidation and resistance in contacts
- Preparation:
Ignition OFF
- Check ground points 31/32 and 31/33, the cables between the ground points and the control module #A20 and #A29, and the control module connector for contact resistance and oxidation according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22





20. Checking throttle position sensor signal from ECM
- Preparation:
Ignition ON
- Connect a voltmeter between #50 (#B20) and #20 (#A20) on the test box.
- The voltmeter should normally read approx. 0.5 volts at closed throttle position.
- The voltage must not drop below 0.1 volts at closed throttle position.
- Is reading is OK?
YES: Proceed to step 20
NO: Proceed to step 21





21. Checking for oxidation and resistance in contacts
- Preparation:
Ignition OFF
- The DTC was set because of poor contact in the control modules' connectors.
- Check and correct the control modules' connectors for contact resistance and oxidation according to step 5 of checking for permanent faults. Checking For Permanent Faults
- Then continue with step 22
22. Checking throttle position sensor circuit
- Check the throttle position sensor circuit according to the relevant information for the ECM installed, refer to Powertrain Management.
Fenix 5.2:
DTC: EFI-243, Throttle position sensor signal, permanent fault
LH 3.2, EZ1 29K MFI control module
- DTC EFI-411 Throttle position sensor signal, permanent fault, signal too low.
Motronic 4.3:
DTC: EFI-243, Throttle position sensor signal, permanent fault, signal too low
Motronic 4.4:
DTC: EFI-243, Throttle position sensor signal, permanent fault, signal too low
- hen continue with step 22




22. Verification
- After repairs have been completed they must be verified as follows to ensure the fault has been eliminated:
- Preparation:
Ignition OFF
Wait approx. 10 seconds.
Ignition ON
Wait approx. 15 seconds.
- Read off the status of the (DTC).
- Does the status indicate INTERMITTENT FAULT?
YES: Fault corrected
NO: Proceed to step 23
23. Fault-tracing information
- The verification result shows that the fault persists.
- Do you want to exit fault-tracing?
YES: Fault not corrected
NO: 1





24. Intermittent fault
- Preparation:
Ignition OFF
- Check connectors on the TCM on the ECM for:
Loose contacts according to step 5 of checking for intermittent faults. Checking For Intermittent Faults
Oxidation and resistance in contacts according to step 6 of checking for intermittent faults. Checking For Intermittent Faults
- Check the cable between the TCM #B20 and the ECM #B20 (Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4), for:
Intermittent open-circuit according to step 2 of checking for intermittent faults. Checking For Intermittent Faults
Intermittent short-circuit to ground according to step 3 of checking for intermittent faults. Checking For Intermittent Faults
- On cars with ECM type LH 3.2/EZ129K, also check the cable between ECM LH 3.2 #B20 and EZ129K #B20 for intermittent short-circuits to ground according to step 3 of checking for intermittent faults. Checking For Intermittent Faults
- Check the ground point 31/33 for contact resistance and oxidation according to step 6 of checking for intermittent faults. Checking For Intermittent Faults
- Check the throttle position sensor circuit according to the service procedures for the engine control module (ECM) installed.
Fenix 5.2:
DTC EFI-243 throttle position sensor signal, intermittent fault
LH 3.2
DTC EFI-411 throttle position sensor signal, intermittent fault, signal too low
Motronic 4.3
DTC EFI-411 Throttle position sensor signal, intermittent fault, signal too low
Motronic 4.4
DTC EFI-411 Throttle position sensor signal, permanent fault, signal too low
- Then continue with step 25
25. 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 step 1
NO: Proceed to step Operation done


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