My 940 took me to the store then decided it didn't want to go home - no start. I checked the fuel codes and got 3-1-2 which according to brickboard means "Signal missing for knock-related fuel enrichment" and "Wiring break between EZK terminal 4 and FI #28". What and where is that?

 

I don't know about that obscure code but I am careful not to pay too much attention to OBD1 codes on any car, especially our Volvos.

Please provide some more detail about the event itself, then we could help.
Under what you have provided, I'd say Fuel Relay (or pump), CPS, or something more obvious, like battery.

 

lev is right, the codes on our cars seem to be wrong most of the time unlike the newer cars. If the car started after it cooled down a bit it could be the CPS or the ignition control module.

 

Thanks for the response. Actually it was the right code. Before I even followed the Brickboard testing procedure I hopped over to pick n pull and popped in a used knock sensor and it instantly started. Another relief! It fact, it seems to run better than it did before, tach needle is very steady. Within 100 miles I've had the crank and knock sensors go out. Who'd a thunk it? Oh well, I'm glad they went out close to home. I'm wondering if the temp and oil sensors might be next?

 

Never seen a knock sensor stop a b230 from running, but OK, anything is possible...

 

Crank position sensors are a wear item and need to be replaced every 150-200k miles. I've never had a knock sensor go bad nor had a no-start situation due to a knock sensor. I have had my car lose the signal from the knock sensor but it should automatically revert to a retarded timing "limp home mode" and still run. I had this happen twice due to poor connection of the wire to the knock sensor and the car would drive with significantly less power.

Never had an oil sensor go bad.

Temp sensor for ECU do tend to fail though

 

That's what I thought - that knock sensors never go bad. I didn't know about "limp mode" so after draining the battery trying to start it I had the car towed home. Looked up the knock sensor testing procedure and saw the reference to limp mode. So I disconnected the connector and it started up in limp mode, wish I knew that before towing it. Reconnected it and it wouldn't start again. Popped in a used one and it started. So I guess my car is "special" Ha!

 

Just out of curiosity, what other faults will limp mode default to?

 

lack of just about any imporant engine status input will revert to limp mode. MAF failures, CTS (coolant temp sensor) out of range, etc.

 

That's reassuring. I'll remember that. Thanks

 

on a LH2.4 car, any limp home condition will light the check engine light, and have a corresponding blink code.

note, of course, there are sensors for which there's no limping, for instance, the car flat out can't run without the crank position sensor as it has no timing information.

 

Yeah, my car never showed a check engine light when either the crank or knock sensors went out, but did show diagnostic codes.