I've been getting a Check Engine Light with a Fault Code 113, but this time it won't clear.

The car has rebuilt injectors, cleaned grounds and ample contact cleaner sprayed into the computer connector, so what can "Fault in Fuel Injector(s)" mean?

Rich (Near Pittsburgh)

In a 240 the 113 is set when the ECU gives up trying to match the mixture to the oxygen sensor response when correction is out of range. But I can tell you a lot of unneeded money has been spent on rebuilt and new injectors because of this verbiage. It could be the Motronic actually uses this for injector current, but not your car.

My guess was the words resulted when Bosch tried to explain the diagnostic output to Volvo tech writers who generally want a one-to-one agreement between symptom and part at fault. They tried to say the code is set when nothing done in adjusting the injector pulse duration puts the oxygen sensor into stoich crossing again, i.e. gives up closed loop. If 113 is set, the car is in limp home fuel map.

Pull the fuel injection fuse momentarily to clear all memory and monitor the oxygen sensor output through warm-up and idle. Many faults will cause a 113 from pinholed regulator diaphragms to crusty fuse 4 and no heat at the sensor. Many many reasons. There are no provisions in the LH2.4 ECU hardware to monitor injector current.
--
Art Benstein near Baltimore


Those who get too big for their britches will be exposed in the end. Especially those in possession of unneeded money.

interesting. i've fixed 113 with a new relay and not an o2 in the past. that is, i THINK i have.

113 was described to me as a power loss to the injectors, hence, replace the relay. better study my lh 2.4, i guess. been too long. thanks, chuck.

Chuck, I think you are right and your memory is sharp. The relay is well known to 240 owners, to the point many have one in their glove box.

Could indeed have been the relay.

Here's how:

The FI relay switches two circuits. The "system" circuit powers everything in the fuel system -- injectors, air mass meter, idle motor, and the fuel computer itself. The "pump" circuit powers the fuel pumps and the oxygen sensor heater.

The only function the ECU, or fuel computer, performs when not powered by the system relay is retention of stored trim and code memory. That's all it has power to do, directly from the battery. When the ignition key is turned on, a simple circuit in the ECU picks the system relay, which powers the remainder of the ECU and keeps it powered after the key is shut off, long enough to do the cleaning of the hot wire in the air mass meter.

If the system relay portion had a cold solder, the whole computer might suffer unstable power. Operation would be unpredictable. If the pump relay portion had the flaky solder, the fuel delivery might be questionable, as well as the oxygen sensor heat, resulting in a mixture control failure -- the 113.

I have to emphasize, the 113 is not an indictment of the oxygen sensor itself. Many other faults can result in the oxygen sensor providing feedback which prevents closing the control loop. This includes a laundry list of vacuum leaks, exhaust leaks, fuel pressure faults, AMM, temp sensor, and electrical faults such as poor ground wiring -- or what I'm dealing with today -- rusty spin flange at the cat. Anything that can screw up the mixture after warm up.
--
Art Benstein near Baltimore

No wonder nobody comes here; it's too crowded. (Yogi)

Time to chime in.

I recently had a 1-1-3 happen to me, but the "fault in fuel injectors" in the Haynes manual may not be correct.

Check here: https://www.volvoclub.org.uk/faq/EngineOBDCodes.html
Here it says 1-1-3 means "Fuel trim (lambda control) too lean or rich".

I agree with Art that this may not be related to the O2 sensor as in my 245 the cause turned out to be an intermittent fault in the fuel pressure regulator.

Lately, it started misfiring just after the cold start and then clear up within 30 s or so. Touching the accelerator during this half a minute only made it worse. So it was start, wait a minute, drive.

After some thinking about the functioning of the LH 2.4 during the first few minutes, when the O2 sensor doesn't give reliable data and is thus ignored by the ECU, I decided that the pressure regulator was the most likely cause.
No, there was no fuel leakage on the vacuum side and yes, there was also a healthy volume of fuel going back into the return line. But the replacement solved the problem.

So, the 1-1-3 during driving was probably thrown when the regulator decided to stick for a moment resulting in hitting the limits of the adjustment range.
After the replacement of the regulator, no codes have been thrown and the too rich running just after the cold start has been solved.

In other words: 1-1-3 doesn't really tell you the cause, only a symptom. You will have to exclude possible causes one by one.

Assuming you have an 89 plus 200 series it may be a problem with the O2 sensors wiring / connector? It sounds like you were reading from the motronics 1.8 column.
Dan

replace the fuel pump relay. it powers the injectors and is dropping out. the ecm sees the amp draw fall and sets the code. good luck, chuck.