Part 1
Signal too low
Status message
Note! To obtain the correct status message the ignition must be switched on for approx. 15 seconds before the diagnostic trouble code (DTC) is read off.
Read off diagnostic trouble code (DTC).
Is the status PERMANENT FAULT displayed?
Yes - Checking the throttle position (TP) sensor signal
No - Intermittent fault
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Other diagnostic trouble codes (DTCs)
Read off OTHER DTCs in engine management system (Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4).
Are diagnostic trouble codes (DTCs) EFI-243 for the Fenix 5.2, EFI-411 for the LH 3.2, EFI-411 for the Motronic 4.3 or EFI-411 for the Motronic 4.4 stored?
Yes - Fault-tracing information
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Fault-tracing information
Fault-trace according to engine management system diagnostic trouble code (DTC) (EFI-243 for the Fenix 5.2, EFI-411 for the LH 3.2, EFI-411 for the Motronic 4.3 or EFI-411 for the Motronic 4.4).
Continue - Verification
FAULT-TRACING FAILED
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Checking the throttle position (TP) sensor signal
- Ignition on.
- Go into scrolling values.
- Read off the throttle position (TP) sensor signal.
Floor the accelerator pedal (AP) and check if the throttle position (TP) sensor signal increases.
Does the value increase?
Yes - Checking throttle position (TP) sensor circuit
No - Checking throttle position (TP) sensor circuit
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Checking signal cable resistance to ground
- Ignition off.
- Engine control module (ECM) disconnected (both control modules LH 3.2 and EZ129K).
- Disconnect the transmission control module (TCM).
Connect an ohmmeter between ground and the breakout box:
- #50 (#B20) for LH 3.2
- #20 (#B20) for Fenix 5.2, Motronic 4.3 and Motronic 4.4.
The ohmmeter should read approx. 0 ohms.
OK - Checking signal from engine control module (ECM)
Not OK - Checking for a short-circuit
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Checking for a short-circuit
- Check cable between transmission control module (TCM) #B20 and engine control module (ECM) #B20 (Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4) for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
- On cars with engine control module (ECM) type LH 3.2/EZ129K, also check the cable between engine control module (ECM) LH 3.2 #B20 and EZ129 K #B20 for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking signal from engine control module (ECM)
- Ignition off.
- Connect the engine control module (ECM).
- Ignition on.
Connect an voltmeter between ground and the breakout box:
- #50 (#B20) for LH 3.2
- #20 (#B20) for Fenix 5.2, Motronic 4.3 and Motronic 4.4.
The voltmeter should normally read approx 0.5 V at closed throttle position (CTP). The voltage should not drop below 0.1 V at closed throttle position (CTP).
Is the reading OK?
Yes - Connecting the breakout box
No - Checking throttle position (TP) sensor circuit
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Checking throttle position (TP) sensor circuit
Further fault-tracing depends on the vehicle's engine control module (ECM).
Select control module.
- Fenix 5.2 - diagnostic trouble code (DTC) EFI-243 Throttle position (TP) sensor signal, permanent fault, signal faulty
- LH 3.2 - Throttle position (TP) sensor signal, permanent fault, signal too low
- Motronic 4.3 - diagnostic trouble code (DTC) EFI-411 Throttle position (TP) sensor signal, permanent fault, signal too low
- Motronic 4.4 - diagnostic trouble code (DTC) EFI-411 Throttle position (TP) sensor signal, permanent fault, signal too low
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Checking signal to the transmission control module (TCM)
- Ignition off.
- Engine control module (ECM) connected.
- Ignition on.
Connect a voltmeter between #50 (#B20) and #20 (#A20) on the breakout box.
The voltmeter should normally read approx 0.5 V at closed throttle position (CTP). The voltage should not drop below 0.1 V at closed throttle position (CTP).
Is the reading OK?
Yes - Checking for contact resistance and oxidation
No - Checking for an open-circuit
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Checking for contact resistance and oxidation
- Ignition off.
The cause of the diagnostic trouble code (DTC) has been loose connections in the control module connectors. Check control module connectors for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking for an open-circuit
Check cable between automatic transmission control module (TCM) #B20 and engine control module (ECM) #B20 for the Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4 for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking voltage drop over the engine control module (ECM) signal ground.
- Ignition off.
- Engine control module (ECM) connected.
- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between ground terminals 31/33 and the breakout box:
Make a note of the voltmeter reading.
Continue - Connecting the breakout box
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Checking voltage drop over the transmission control module (TCM) signal ground
- Ignition off.
- Connect the control modules.
- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between ground terminal 31/33 and #20 (#A20) on the breakout box. Make a note of 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 V.
OK - Checking voltage drop over signal ground and power ground
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Ignition off.
Check ground terminal 31/33 and transmission control module (TCM) connectors for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking voltage drop over signal ground and power ground
- Ignition on.
- Turn on as many power consuming components as possible.
Connect a voltmeter between #20 (#A20) and #29 (#A29) on the breakout box.
The voltmeter should read less than 0.6 V.
OK - Checking throttle position (TP) sensor signal from engine control module (ECM)
Not OK - Checking for contact resistance and oxidation
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Checking for contact resistance and oxidation
- Ignition off.
Check ground terminals 31/32 and 31/33, the cables between the ground terminals and control module #A20 and #A29, and the control module connector for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Select "Continue" when the fault has been repaired.
Continue - Verification
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Checking throttle position (TP) sensor signal from engine control module (ECM)
- Ignition on.
Connect a voltmeter between #50 (#B20) and #20 (#A20) on the breakout box.
The voltmeter should normally read approx 0.5 V at closed throttle position (CTP). The voltage should not drop below 0.1 V at closed throttle position (CTP).
Is the reading OK?
Yes - Checking for contact resistance and oxidation
No - Checking throttle position (TP) sensor circuit
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Checking for contact resistance and oxidation
- Ignition off.
The cause of the diagnostic trouble code (DTC) has been loose connections in the control module connectors. Check control module connectors for contact resistance and oxidation and remedy according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Continue - Verification
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Verification
Verification
Hint: After repairs have been completed they must be verified as follows to ensure the fault has been eliminated:
- Ignition off
- Wait approx. 10 seconds.
- Ignition on.
- Wait approx. 15 seconds.
Read off the status of the Diagnostic trouble code (DTC).
Does the status indicate INTERMITTENT FAULT?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFIED - FAULT FOUND
VERIFICATION FAILED - Fault-tracing information
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Fault-tracing information
Information
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.
Do you want to exit fault-tracing?
Yes - Exit fault-tracing
No - Attempt New Test
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Attempt New Test - Status message
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Intermittent fault
Signal too low. Intermittent fault
Intermittent fault
- Ignition off.
- Check transmission control module (TCM) and engine control module (ECM) connectors for loose connections according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check cable between transmission control module (TCM) #B20 and engine control module (ECM) #B20 (Fenix 5.2, LH 3.2, Motronic 4.3 or Motronic 4.4) for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , and an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- On cars with engine control module (ECM) type LH 3.2/EZ129K, also check the cable between engine control module (ECM) LH 3.2 #B20 and EZ129K #B20 for an intermittent short-circuit to ground according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults. Check ground terminal 31/33 for contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Select "Continue" when the fault has been repaired.
Continue - Checking throttle position (TP) sensor circuit
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Checking throttle position (TP) sensor circuit
Further fault-tracing depends on the vehicle's engine control module (ECM).
Select control module.
- Fenix 5.2 - diagnostic trouble code (DTC) EFI-243 Throttle position (TP) sensor signal, intermittent fault, signal faulty
- LH 3.2 - Throttle position (TP) sensor signal, intermittent fault, signal too low
- Motronic 4.3 - diagnostic trouble code (DTC) EFI-411 Throttle position (TP) sensor signal, intermittent fault, signal too low
- Motronic 4.4 - diagnostic trouble code (DTC) EFI-411 Throttle position (TP) sensor signal, intermittent fault, signal too low
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Signal faulty. Intermittent fault
2-4-3 TP sensor signal
Checking leads and connections
- Check TP sensor and control module connectors for loose contacts as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and contact resistance and oxidation as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check lead between #A15 and connector terminal 2 for intermittent open circuit as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , intermittent short-circuit to ground as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and intermittent short circuit to supply as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check lead between #A16 and connector terminal 3 for intermittent open circuit as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults , intermittent short-circuit to ground as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults and intermittent short circuit to supply as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
- Check lead between #A18 and connector terminal 1 for intermittent open circuit as per Checking wiring and terminals. Intermittent faults Checking Wiring and Terminals. Intermittent Faults.
Press Continue when fault is repaired.
Continue -
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