Check Engine: Error code 27

[Swedish Snake]

OK, I'm having problems with my 1994 RT/10.

Everytime I start up the car and let it idle, I get CHECK ENGINE and the error code is 27, Fault in injector driver interface circuit.

So today I changed all ten injector sockets and got a much smoother idle and if I stay above 2000 rpm, there's no CHECK ENGINE. But as soon as I step of the pedal, the light comes on.

I even removed the piggy back ECU from Civinco, no change to the above

Since the knowledge for troubleshooting a Viper V10 here in Sweden are very limited, I'm asking my fellow snake lovers if anyone knows what could be the problem with my car.

Any advice is appreciated and I'll buy you a drink if your ever in Stockholm, Sweden!

 

[dave6666]

Do you have the factory service manual powertrain diagnostics book? It should if like my '01 manual have a troubleshooting discussion on this. Except mine is OBD2 and I did look to see if I could get that info for you. No error code listed like that for '01 OBD2.

A suggestion though. Isn't there a main harness connector for all the injectors? Check that connection? Pull apart several times to clean contacts? Just and idea. May be way off. Still on coffee and my best ideas come with a pilsner.

 

[Jack B]

OK, I'm having problems with my 1994 RT/10.

Everytime I start up the car and let it idle, I get CHECK ENGINE and the error code is 27, Fault in injector driver interface circuit.

So today I changed all ten injector sockets and got a much smoother idle and if I stay above 2000 rpm, there's no CHECK ENGINE. But as soon as I step of the pedal, the light comes on.

I even removed the piggy back ECU from Civinco, no change to the above

Since the knowledge for troubleshooting a Viper V10 here in Sweden are very limited, I'm asking my fellow snake lovers if anyone knows what could be the problem with my car.

Any advice is appreciated and I'll buy you a drink if your ever in Stockholm, Sweden!

The injector trouble shooting is simple, but, time consuming. That code is probably the equivalent of a P0201A thru P0210A in the OBDII world. You can let the car warm up and idle, then wiggle the injectors connectors and watch for a change.

Next step, pull the connectors one at a time and listen for a difference in engine sound. Please note the rpm will not change. A lot of us have changed out the oem clips and gone to aftermarket clips due to problems like this.

It is possible that at a higher rpm an injector clip with a bad (high resistance) connector might work at a higher voltage (2000 rpm) than at idle (lower voltage).

Here are some more areas to check:

1. The injector resistance should be in the range of 10-20 ohms. Check at the clip.

2. At the PCM check for resistance to ground on each driver circuit. This is the PCM driver to ground and it should be greater than 5 ohms.

3. At the PCM check the resistance of the circuit to the clip, it should be is less than 5 ohms, that indicates a good circuit. This is done with the injector clip removed from the injector.

That is about all you can do, the next step is a PCM replacement. Please note, the ohmic values are those from a Gen II, however, the Gen I, should be in the same range, since we are looking for coarse values.