VOLVO
LPG-0727 - Engine speed (RPM) signal. Signal missing
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 LPG control module receives the engine speed from the engine control module (ECM). The code is set when the speed signal is missing while the engine runs, and since the signal comes from there, the codes in the engine control module should be read first.
Possible causes
- Contact resistance or oxidation in the connector on the LPG control module
- Contact resistance or oxidation in the connector on the engine control module (ECM)
- Open circuit in the signal wire
- Signal wire short-circuited to ground or supply voltage
- Faulty engine speed signal from the engine control module (ECM)
What you can do
- 1Read the codes in the engine control module (ECM) first and remedy them as needed, since the speed signal originates there
- 2With diagnostic equipment, start the engine and check that the speed rises and falls as the throttle changes; if it looks normal, the fault has probably not been active recently
- 3Check the connectors on the LPG control module and the engine control module for poor contact and oxidation
- 4Check the signal wire for breaks, chafing and damage, and use a multimeter to confirm it has no contact with ground or supply voltage
- 5Erase the code and road test the car to see whether it returns
Symptoms you may notice1
- The engine does not run on gas
General guidance for car owners. Diagnosis on the car can point to a different cause.