VOLVO
LPG-0123 - Throttle position (TP) sensor. Signal too high
System
Liquid Petroleum Gas (LPG)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS40 (1996–2004), V40 (1996–2004)
Show models by year and engine (2)
What does this fault code mean?
The throttle position sensor measures the opening angle of the throttle. Both the LPG control module and the ECM use this signal, and the code is set when the LPG control module sees the signal as too high with the engine idling. Codes in the engine control module should be read first.
Possible causes
- Contact resistance or oxidation in the connector on the throttle position sensor
- Contact resistance or oxidation in the connector on the engine control module (ECM)
- Contact resistance or oxidation in the connector on the LPG control module
- Short circuit to supply voltage in the throttle position sensor signal wire
- Open circuit or short circuit to supply voltage in the ground wire of the throttle position sensor
- Defective throttle position sensor
What you can do
- 1Read the codes in the engine control module (ECM) first, since the signal is shared with it
- 2With diagnostic equipment, let the engine idle and read the throttle angle; if the value looks normal, the fault has probably not been active recently
- 3Check the connectors on the throttle position sensor, the engine control module and the LPG control module for poor contact and oxidation
- 4Check the signal wire to the throttle position sensor for chafing and damage, and use a multimeter to confirm it has no contact with supply voltage
- 5Check the ground wire to the throttle position sensor for breaks, and use a multimeter to confirm it has no contact with supply voltage
- 6Have a workshop replace the throttle position sensor if no fault is found
Symptoms you may notice1
- Poor performance
General guidance for car owners. Diagnosis on the car can point to a different cause.