N108 p-1248 "fault code"17656!!!

[estergard]

I read the previous threads on this problem, and have determined my COLD START INJECTOR VALVE has no power to it, is shorted out, or it's stuck. I get the FAULT CODE: 17656 on my VCDS. My timing is stuck advanced at 255, which indicates there is no power to the COLD START INJECTOR VALVE. My question is: How do I determine if the valve is STUCK? Is there a way to UNSTICK IT, and test it....besides putting it in and out of the car repeatedly? I have done 3 IP installations (installing another IP for testing), already! I'm getting a little too familiar with the process. Please offer help!

With the IP out of the car, and the valve on the bench...I just put 12 volts on the valve, and it "clicks". I tested the #34 fuse, and it's good...as well as the BROWN wire, at the connector plug (for the IP). If the valve has power, and clicks...can it still be a BAD PART?

[Keithuk]

VAG Error Code: 17656
EOBD II Error Code: P1248

Fault Location:
Start of injection - control difference

Possible Cause:
Loss of Power at high Engine Speeds.
Engine difficult to Start.

Start of Injection Timing Regulation not OK.
Injection Pump Control Range blocked/dirty (e.g. by Metal Particles).
Engine has stalled / ran out of Fuel recently.
Wiring/Connectors from/to Injection Valve (N108) faulty.
Injector needle lift sensor.
Fuel level low.
Pump timing.

Possible Solutions:
Check/Adjust Injection Start.
Check Fuel Supply.
Check/Replace Fuse(s).
Check/Repair Wiring/Connectors from/to Injection Valve (N108).

Special Notes:
Might by stored with other codes like 17654/P1246/004678.

Check if you have power with a multimeter.

Fuse 34 is located in the Fascia 1 fusebox inside its a 10amps fuse for Engine Management.

[estergard]

My car was bought at auction with a blown engine, and no history. The engine is rebuilt now. It started easily, and runs smooth....but, will not rev past 1100 rpm's. The timing (checked with VCDS) is stuck on 255 with a straight YELLOW VERTICAL LINE. The only FAULT CODE is 17656/P1428. If cleared...it returns immeadiately. All codes and information point to the N108 COLD START VALVE. I have another IP which I'd like to steal the N108 off, but I want to test it prior to installation. Is there a way to test a used N108, without installing it on the car?

[estergard]

I tested the N108 and it reads 15 ohms. It clicks when 12 volts are put on it. Does that mean it's DEFINITELY good?

[chittychittybangbang]

Through VCDS output test, does anything happen if you get to the n108 test part? If it's clicking the solenoid is moving, I think it should be good.

One weird thing I've heard of is a transfer pump pressure valve failing, I don't think it will cause that error code but worth checking out. Please keep us updated on your progress. The valve is above the fuel line, remove cap and inside is a valve which tends to fall apart, results in low fuel pressure.

The pins on the main connector are #9 and 10, those are the ones you're checking right?

[estergard]

I checked #9. and #10. The #9 (Brown) tested good, but #10 did not light the test light. #10 was black, so I assumed it was a ground...is it? I switched the pump under the rear seat, and it had fallen apart, as you described. Somebody had broken both quick connectors on the fuel lines, as well...so I replaced both fuel lines (from the pump to the long lines under the car, at the fuel tank). Two nights ago, (before I looked at the lift pump) I sat there for 2 hours, with a hand-operated vaccuum pump...pulling fuel through the IP, trying to get fuel without big marching bubbles. I NEVER COULD GET RID OF THOSE BUBBLES!

Today's question: is the #10 BLACK wire supposed to light up my test light?

[chittychittybangbang]

I don't think you have a lift pump, your 99 should have only fuel level sensor in fuel tank. Some people have problems with the o-rings and pickup on the level sensor.

I meant the transfer section on injection pump, the area on the left whenlooking at it has a valve under fuel line which has a role in pump pressure. I'm not an expert on pump innards but this valve is a common problem.

Not sure about alh pump, been a while since I've worked on them. Ground is normally brown.

[estergard]

I seem to be chasing a phantom. My readouts keep changing, and now I get ERROR CODES when I go to look at the ADJUSTMENTS, after logging in. I have a bad MAF FAULT CODE now...even when switching MAF's. They read a "Stuck" value of 550. Sometimes my timing reads 255 (with a vertical YELLOW LINE), and sometimes it's on 48 BTC. I installed ALL NEW vaccuum lines properly, and replaced the Turbo & EGR solenoids. I vaccuum-tested the Turbo Actuator. The only difference is...now I can rev up to 2000 rpm's, instead of 1100 rpm's.

[estergard]

I solved the problem tonight. When I switched the crankshaft position sensor plug on the wiring harness, I did not put the 3 wires in the proper holes. I had 1 & 2 switched. Because they are a part of the electronic system...the Fuel Quantity Adjuster, The #3 Injector's Needle Lift Sensor, The Crankshaft Position Sensor, The Fuel Temp Sensor, and the Cold Start Advance Selenoid all report to the ECU, so the Timing, and Start of Injection Timing work as they should.

[chittychittybangbang]

Thanks for the follow up, it's always nice to know what potential problems there are.