Mechanics

NO SIGNAL TO FUEL INJECTORS

1999 Volkswagen Jetta • 4 cylinder FWD Automatic • 175,000 miles

1. 1999 jetta (gas) no signal to injectors
Hello all
I have a 1999 jetta that has stopped running. It has a new fuel pump relay and the pressure at the fuel rail is good. Also new coil, plugs, and wires. The throttle body has also been completly cleaned.
If you spray starter fluid in the throttle body it starts up for a few seconds.
I put the noid lights on the injector connector but had no signal at all. Ran the scanner and got codes
po303
p1300
p1225
p1226
p1227
p1228
p1425
p1472
p1582
p0102
The codes overlap some of the issues but it seems to indicate a short circut in the evap or fuel system. Need to know if anyone has been down this rbefore and where to look next.
Thanks
Larry
Avatar
Thefox48
August 24, 2011.



P0303 - Cyinder 3 misfire detected.
P1300 - Unable to find any information our database but should be related to P0300
P1225 - Cylinder 1 injector circuit shorted to ground
P1226 - Cylinder 2 injector circuit shorted to ground
P1227 - Cylinder 3 injector circuit shorted to ground
P1228 - Cylinder 4 injector circuit shorted to ground
P1425 - Tank Vent Valve shorted to ground
P1472 - EVAP emission control LDP circuit short to ground
P1582 - Idle Adaptation at limit.
P0102 - Mass or Volume Air Flow Circuit Low Input.

Since vehicle is not starting, I would suggest starting with the injector circuit first.

FUEL INJECTORS, CHECKING
Checking activation

Check activation of fuel injectors.

Special tools, testers and auxiliary items

a) VAG 1598/18 test box
b) Multimeter (Fluke 83 or equivalent)
c) VAG 1527B voltage tester
d) Connector test kit VW 1594
e) Wiring diagram

Check conditions

a) Engine speed sensor OK
b) Fuel pump relay OK

Test sequence

Remove intake manifold, upper, see Fig. 2, item 7.
Disconnect harness connector -1- from connection -2- and connect VAG 1527B voltage tester with test leads from VW 1594 to the terminals of the harness connector.

Disconnect harness connectors from fuel injectors 2-4.

Operate starter and check the voltage supply for no. 1 cyl. Fuel injector.

LED must flicker

Repeat check on fuel injectors 2-4.

If the LED does not flicker: Turn off ignition.

Connect VAG 1598/18 test box to ECM wiring harness.
Fig. 118: Connecting VAG 1598/18 Test Box To ECM Wiring Harness

Check wiring between test box and connector for open circuit according to wiring diagram.

No. 1 cyl. Fuel injector: terminal 2 and test box socket 24

No. 2 cyl. Fuel injector: terminal 2 and test box socket 25

No. 3 cyl. Fuel injector: terminal 2 and test box socket 26

No. 4 cyl. Fuel injector: terminal 2 and test box socket 02

Resistance: maximum1.5 ohms (ohm)
Fig. 119: Checking Wiring Between Test Box And Fuel Injector Connector

Check wiring between fuel injector connector terminal 1 and relay panel for open circuit according to wiring diagram.

Resistance: maximum 1.5 ohms (ohm)

Additionally, check wires for short circuit to one another.

Specification: "infinity" ohms (ohm)

Checking resistance of fuel injectors

Check resistance of fuel injectors individually
Fig. 120: Checking Resistance Of Fuel Injectors

Specification: 15-20 ohms (ohm)

If the specification is not attained, replace fuel injector(s) as necessary.


KHLow2008
Aug 25, 2011.
No need to run all these tests.

Replace the FP relay.


F4I_guy
Aug 27, 2011.
The fuel pump relay has been replaced.
Could this be an issue with the ignition switch?
The cruise control stopped working right before all this happened.


Tiny
Thefox48
Sep 9, 2011.
If it is an ignition switch problem, you would not be getting any sparks as well.

At the injector circuit, ensure there is battery voltage at the RED/Violet wire with ignition switch turned on and while cranking. If voltage is available, the fuel pump relay is working correctly.

The cruise control is linked to the ECM. Check fuse # 5 in fuse panel behind left sie of dash. Use a DVOM to check the Black. Blue wire for battery voltage with inition switch turned on. If voltage is available, ensure White/Yellow wire from switch has battery voltage. If voltae is available, you could have a faulty ECM.


KHLow2008
Sep 10, 2011.