Knocking in Dash and Brakes

With the ABS light on, you need to scan it for C and U codes, these don't set the check engine light, but scanning it will pinpoint the problem area, this is ALWAYS the first step.

Also there is a known issue of a bad ground for the brake module, follow this proceedure to eleiminate this first.
Reference Number(s): SB04-09-S003, Date of Issue: OCTOBER, 2004
Related Ref Number(s): SB04-09-S003
ARTICLE BEGINNING
SERVICE INFORMATION
Condition: Some customers may comment that the ABS light is on. Upon further
inspection, DTCs C0265 and C0201 may be set in the brake module. It is also possible
for DTC U1041 to set in other modules. There may also be a loss of communication
with the brake module.
Possible Cause: A poor connection at the EBCM Ground 304 is causing unnecessary
replacements of brake modules.
Correction: Perform the service procedure to improve the connection of the EBCM
Ground 304.
SERVICE PROCEDURE
1. Remove the EBCM Ground 304. The EBCM Ground is located on the frame
beneath the driver's side door. If multiple grounds are found in this location, the
EBCM ground can be identified as the heavy (12-gauge) wire.
2. Clean the area, front and back, using a Whiz Wheel (R).
3. Install the bolt, ground and a star washer to the frame.
4. Install a star washer and nut on the backside of the frame and tighten the nut to 9
N.m (79 lb in).
5. Cover the front and back side of the repair area using Rubberized Undercoating
p/n 8--12378-398-0 or equivalent.
ISUZU: 2003-2004 Ascender
AFFECTED VEHICLES:2003--2004 Isuzu Ascender (US/UT) models.
NOTE: Do not replace the brake module.