P1649 + ABS Light = ?

[Fl_bug]

Just wondering, but I scanned a car that had an ABS light on. The car drove great and everything.... until it came time to stop. The brakes were very poor and felt like it was missing power.

The car had error code
p1649-Data Bus Powertrain Missing message from ABS control module

I'm going to go on a limb and say the ABS Pump need to be replaced... However, that is almost $2k in parts! Any chance there is a vacuum unplugged or bad sensor?

[Fl_bug]

bump

[NewBeetleMechanic]

Fuses are all good?

[Fl_bug]

Originally Posted by NewBeetleMechanic

Fuses are all good?

Yes

[NewBeetleMechanic]

What kind of car?

[Fl_bug]

Originally Posted by NewBeetleMechanic

What kind of car?

Check your PM Inbox.

Its on a 2003 Jetta TDI

[NewBeetleMechanic]

Use a Digital Volt Ohm Meter (DVOM) to measure voltage at pin 7 of the Diagnostic Link Connector (DLC). If full battery voltage is present a problem in the K data communication line is indicated. Normal voltage will run from about 2.0 volts to a maximum of about 10.5 volts. Check for installation of an aftermarket radio. If an aftermarket radio has been installed, the radio wiring harness must be modified to prevent the aftermarket radio from applying battery voltage to the K data line. Remove the radio and look at the black 8 pin connector. Pin 3 of the black 8 pin connector is the K data line. Remove pin 3 from the connector and tape it back on the harness in such a manner as to preclude shorting. Replace the radio and check for correct voltage at pin 7 of the diagnostic link connector. Volkswagen Factory bulletin Group 91 bulletin # 99-0 addresses the wiring modifications neccesary when an aftermarket radio is installed. A related document, Volkswagen Factory bulletin Group 91 bulletin # 99-01, is available.

Test and fix:

If 0 volts is present on Pin 7 of the diagnostic link connector a potential short to ground in the wiring harness or a shorted controller on the K data line is indicated. Disconnect controllers on the K data line one at a time while monitoring DLC pin 7 voltage. If DLC Pin 7 voltage returns to normal after a controller is disconnected an internal short in the controller is indicated.

[Fl_bug]

Originally Posted by NewBeetleMechanic

Use a Digital Volt Ohm Meter (DVOM) to measure voltage at pin 7 of the Diagnostic Link Connector (DLC). If full battery voltage is present a problem in the K data communication line is indicated. Normal voltage will run from about 2.0 volts to a maximum of about 10.5 volts. Check for installation of an aftermarket radio. If an aftermarket radio has been installed, the radio wiring harness must be modified to prevent the aftermarket radio from applying battery voltage to the K data line. Remove the radio and look at the black 8 pin connector. Pin 3 of the black 8 pin connector is the K data line. Remove pin 3 from the connector and tape it back on the harness in such a manner as to preclude shorting. Replace the radio and check for correct voltage at pin 7 of the diagnostic link connector. Volkswagen Factory bulletin Group 91 bulletin # 99-0 addresses the wiring modifications neccesary when an aftermarket radio is installed. A related document, Volkswagen Factory bulletin Group 91 bulletin # 99-01, is available.

Test and fix:

If 0 volts is present on Pin 7 of the diagnostic link connector a potential short to ground in the wiring harness or a shorted controller on the K data line is indicated. Disconnect controllers on the K data line one at a time while monitoring DLC pin 7 voltage. If DLC Pin 7 voltage returns to normal after a controller is disconnected an internal short in the controller is indicated.

Thankyou very much! I will be keeping this information handy! I'll let you know how it goes

[Fl_bug]

Update!

Simply clearing the code did it actually. No more ABS light and no more CEL. The brakes were functioning perfectly too!!

Just in case any of this comes back, i'll be sure to give the above suggestions a peek!

Thanks Mr. Mech!

[NewBeetleMechanic]

Originally Posted by Fl_bug

Update!

Simply clearing the code did it actually. No more ABS light and no more CEL. The brakes were functioning perfectly too!!

Just in case any of this comes back, i'll be sure to give the above suggestions a peek!

Thanks Mr. Mech!

Glad to help.