Pinpoint Test N : C0021:00, C0021:21, C0021:66, C0021:77

N1 CHECK THE ABS (ANTI-LOCK BRAKE SYSTEM) MODULE DIAGNOSTIC TROUBLE CODES (DTCS)

Ignition ON.

Using a diagnostic scan tool, carry out the ABS module self-test.

Are other Diagnostic Trouble Codes (DTCs) present in the ABS module in addition to DTC C0021:21, C0021:66 or C0021:77?

Yes

The other ABS module Diagnostic Trouble Codes (DTCs) indicate the cause of DTC C0021:21, C0021:66 or C0021:77.DIAGNOSE all other ABS module Diagnostic Trouble Codes (DTCs) before diagnosing DTC C0021:21, C0021:66 or C0021:77. GO to the DTC Chart: ABS Module.REFER to: Anti-Lock Brake System (ABS) and Stability Control .

GO to N2

N2 CHECK THE BRAKE PEDAL AND BRACKET

Inspect the brake pedal, bracket and booster push rod for misalignment or damage. Verify all brake pedal and bracket fasteners are tightened to specification.

Apply and release the brake pedal. Verify the brake pedal moves freely and returns to the full released position.

Is the brake pedal and bracket OK?

Yes

GO to N3

No	REPAIR or INSTALL new components as necessary.REFER to: Brake Pedal and Bracket .Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

N3 CHECK THE BRAKE BOOSTER AND BRAKE MASTER CYLINDER

Inspect the brake booster and brake master cylinder for misalignment or damage. Verify that all brake booster and master cylinder fasteners are tightened to specification.

Is the brake booster and the brake master cylinder OK?

Yes

GO to N4

REPAIR or INSTALL new components as necessary.For the brake booster, REFER to: Brake Booster .Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).For the brake master cylinder, REFER to: Brake Master Cylinder .Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

N4 CHECK FOR VACUUM LEAKS

Inspect the vacuum pump and brake booster vacuum hoses, lines and fittings for vacuum leaks.

Are the vacuum pump and brake booster vacuum hoses, lines and fittings OK?

Yes

GO to N5

No	REPAIR or INSTALL new components as necessary.Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

N5 CHECK THE BRAKE SYSTEM FOR BRAKE FLUID LEAKS

Inspect the brake system for brake fluid leaks.

Are any brake fluid leaks found?

Yes	REPAIR as necessary. FILL the brake master cylinder reservoir using the specified brake fluid. BLEED the brake system.REFER to: Brake System Pressure Bleeding .Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

GO to N6

N6 CHECK FOR AIR IN THE BRAKE HYDRAULIC SYSTEM

Bleed the brake system.REFER to: Brake System Pressure Bleeding .

Ignition ON.

Using a diagnostic scan tool, clear all Continuous Memory Diagnostic Trouble Codes (CMDTCs).

Test drive the vehicle at speeds greater than 20 km/h (12 mph).

Using a diagnostic scan tool, carry out the ABS module self-test.

Is DTC C0021:21, C0021:66 or C0021:77 present

Yes

GO to N7

No	The system is operating correctly at this time. The concern may have been caused by air trapped in the hydraulic brake system.Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

N7 CHECK FOR CORRECT ABS (ANTI-LOCK BRAKE SYSTEM) MODULE OPERATION

Ignition OFF.

Disconnect and inspect ABS module C135 .

Repair:
- corrosion (install new connector or terminal - clean module pins)
- damaged or bent pins - install new terminals or pins
- pushed-out pins - install new pins as necessary

Connect ABS module C135 . Make sure it seats and latches correctly.

Operate the system and determine if the concern is still present.

Is the concern still present?

Yes

CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new ABS moduleREFER to: Anti-Lock Brake System (ABS) Module .Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).

No	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.Using a diagnostic scan tool, CLEAR the SOBDMC Diagnostic Trouble Codes (DTCs).