In reading posts here I saw much helpful information concerning trouble codes. On Alpha (2003) we just had the Triangle and engine check light, took it to the dealer and were told that a relay switch had to be replaced. I inquired as to the trouble codes and was told they were P3191 and P3101. The relay is being ordered and I was told it was alright to drive the car while waiting. I questioned this and was told the replay is just sending the signal to the screen and nothing is really wrong. I have little faith in this dealer (took Alpha to this dealer for first oil change--they forgot to rotate the tires, since then have had all maintenance done at a dealer we trust more 50 miles away) though things seem to have improved since we last visited (new service manager seemed knowledgable about Prius.) Could someone tell me what the codes mean and if the analysis seems right?
at the moment all i can offer is P3191: Engine does not start P3101: Engine system malfunction what relay switch are they talking about?
It appears that P3191 means that the engine was cranked for at least 100 revolutions, or 6 seconds, without starting. It could be caused by a variety of actual problems, which kept the engine from starting. I can't find the P3101 code, but another Priuschat user tried to fake a higher coolant temperature, and got those same two codes. Priuschat Post That would make me think that your coolant sensor could possibly be bad, or have an intermittent contact, which WILL make the car hard to start.
That sounds like something other than a circuit opening relay is wrong. The service manager seemed to indicate the relay was sending a false signal to the lights. Unless perhaps it is indicating that the engine is being cranked after in fact it has started. Might that be it?
Trouble code P3191 is an Engine code and P3101 is an HV ECU code. Basically the engine failed to start in x amount of time,so even if it did start after that amount of time,the codes were set and the lights came on. The relay stated is the circuit opening relay. It is in the circuit for the fuel pump,so if it failed to close,sending power to the pump,the engine would not start and the lights came on. The relay has a coil on one side and contact points on the other. Power comes in on both the coil and points at one end. The coil is energized by the Engine ECU completing the ground circuit,which pulls the contact points closed. The power on the other side now flows thru the points and to the fuel pump,which turns on, supplying fuel to the engine.This is probably the relay the dealer was refering to and I have replaced those on a few 1st G Prius'. There is a TSB on this, EG011-03. Hope this helps, .
Thanks rick57 and galaxee and keydiver. I feel I have more of an idea of what is going on. It's great to have this expertise on tap here. The Prius is a great car and I love it but it can be intimidating when something goes wrong. :wub: It really helps to get this kind of generous response.
