Buick Regal: Connector Reconnection - Wheel Speed Sensor
Special Tools
EL-35616 Terminal Test Probe Kit
For equivalent regional tools, refer to Special Tools.
When the condition is not currently present, but is indicated in DTC history,
the cause may be
intermittent. An intermittent may also be the cause when there is a customer
complaint, but the symptom
cannot be duplicated. Refer to the Symptom Table of the system that is suspected
of causing the
condition before trying to locate an intermittent condition.
Most intermittent conditions are caused by faulty electrical connections or
wiring. Inspect for the
following items:
- Wiring broken inside the insulation
- Poor connection between the male and female terminal at a connector
- Poor terminal to wire connection - Some conditions which fall under this
description are poor
crimps, poor solder joints, crimping over the wire insulation rather than
the wire itself, and
corrosion in the wire to terminal contact area, etc.
- Pierced or damaged insulation can allow moisture to enter the wiring
causing corrosion. The
conductor can corrode inside the insulation, with little visible evidence.
Look for swollen and stiff
sections of wire in the suspect circuits.
- Wiring which has been pinched, cut, or its insulation rubbed through may
cause an intermittent
open or short as the bare area touches other wiring or parts of the vehicle.
- Wiring that comes in contact with hot or exhaust components
- Refer to Inducing Intermittent Fault Conditions in order to duplicate
the conditions required, in
order to verify the customer concern.
- Refer to Testing for Electrical Intermittents for test procedures to
detect intermittent open, high
resistance, short to ground, and short to voltage conditions.
- Refer to Scan Tool Snapshot Procedure for advanced intermittent
diagnosis and Vehicle Data
Recorder operation.
Testing for Terminal Fretting
Some intermittent conditions can be caused by wire terminal fretting
corrosion. Fretting corrosion is a
build-up of insulating, oxidized wear debris that can form when there is a small
motion between
electrical contacts. The oxidized wear debris can pile up enough at the
electrical contact spots that the
electrical resistance across the connection increases. Movement between the
contacting surfaces as small
as 10 to 100 micrometer can cause fretting. To put this in perspective, a sheet
of paper is about 100
micrometer thick, so fretting motion is small and hard to see. Vibration and
thermal
expansion/contraction are the main sources that create fretting motion. Since
vehicles vibrate and can
experience large temperature swings, they are a good source for fretting motion.
Tin, copper, nickel, and
iron surfaces are all susceptible to fretting corrosion. Fretting corrosion can
be difficult to see but it
looks like small, dark smudges on the terminals contact surface.
To correct a fretting condition disconnect the suspect connector and add
dielectric grease / lubricant
(Nyogel 760G or equivalent, meeting GM specification 9986087) to both sides of
the connector
terminals. Then reconnect the connector and wipe away any excess lubricant. This
will correct the
additional terminal contact resistance due to the terminal fretting corrosion.
Testing for Proper Terminal Contact
It is important to test terminal contact at the component and any inline
connectors before replacing a
suspect component. Mating terminals must be inspected to ensure good terminal
contact. A poor
connection between the male and female terminal at a connector may be the result
of contamination or
deformation.
Contamination may be caused by the connector halves being improperly connected.
A missing or
damaged connector seal, damage to the connector itself, or exposing the
terminals to moisture and dirt
can also cause contamination. Contamination, usually in the underhood or
underbody connectors, leads
to terminal corrosion, causing an open circuit or intermittently open circuit.
Deformation is caused by probing the mating side of a connector terminal without
the proper adapter.
Always use the EL-35616 kit when probing connectors. Other causes of terminal
deformation are
improperly joining the connector halves, or repeatedly separating and joining
the connector halves.
Deformation, usually to the female terminal contact tang, can result in poor
terminal contact causing an
open or intermittently open circuit.
Testing for Proper Terminal Contact in Bussed Electrical Centers
It is very important to use the correct test adapter when testing for proper
terminal contact of fuses and
relays in a bussed electrical center. Use the EL-35616 kit to test for proper
terminal contact. Failure to
use the EL-35616 kit can result in improper diagnosis of the bussed electrical
center.
Follow the procedure below in order to test terminal contact:
1. Separate the connector halves.
2. Visually inspect the connector halves for contamination. Contamination may
result in a white or
green build-up within the connector body or between terminals. This causes high
terminal
resistance, intermittent contact, or an open circuit. An underhood or underbody
connector that
shows signs of contamination should be replaced in its entirety: terminals,
seals, and connector
body.
3. Using an equivalent male terminal/terminated lead, verify that the retention
force is significantly
different between a known good terminal and the suspect terminal. Replace the
female terminal in
question.
Flat Wire Connectors
There are no serviceable parts for flat wire connectors on the harness side
or the component side.
Follow the procedure below in order to test terminal contact:
1. Remove the component in question.
2. Visually inspect each side of the connector for signs of contamination. Avoid
touching either side
of the connector as oil from your skin may be a source of contamination as well.
3. Visually inspect the terminal bearing surfaces of the flat wire circuits for
splits, cracks, or other
imperfections that could cause poor terminal contact. Visually inspect the
component side
connector to ensure that all of the terminals are uniform and free of damage or
deformation.
4. Insert the appropriate adapter into the flat wire harness connector in order
to test the circuit in
question.
Control Module/Component Voltage and Grounds
Poor voltage or ground connections can cause widely varying symptoms.
- Test all control module voltage supply circuits. Many vehicles have
multiple circuits supplying voltage to a control module. Other components in
the system may have separate voltage supply circuits that may also need to
be tested. Inspect connections at the module/component connectors, fuses,
and any intermediate connections between the voltage source and the
module/component. A test lamp or a DMM may indicate that voltage is present,
but neither tests the ability of the circuit to carry sufficient current.
Operate the component to test the ability of the circuit to carry sufficient
current. Refer to Circuit Testing and Power Distribution Wiring Schematics.
- Test all control module ground and system ground circuits. The control
module may have multiple ground circuits. Other components in the system may
have separate grounds that may also need to be tested. Inspect grounds for
clean and tight connections at the grounding point. Inspect the connections
at the component and in splice packs, where applicable. Operate the
component to test the ability of the circuit to carry sufficient current.
Refer to Circuit Testing and Ground Distribution Wiring Schematics.
Temperature Sensitivity
- An intermittent condition may occur when a component/connection reaches
normal operating
temperature. The condition may occur only when the component/connection is
cold, or only when
the component/connection is hot.
- Freeze Frame, Failure Records, Snapshot, or Vehicle Data Recorder data
may help with this type
of intermittent condition, where applicable.
- If the intermittent is related to heat, review the data for a
relationship with the following:
- High ambient temperatures
- Underhood/engine generated heat
- Circuit generated heat due to a poor connection, or high electrical
load
- Higher than normal load conditions, towing, etc.
- If the intermittent is related to cold, review the data for the
following:
- Low ambient temperatures - In extremely low temperatures, ice may
form in a connection
or component. Inspect for water intrusion.
- The condition only occurs on a cold start.
- The condition goes away when the vehicle warms up.
- Information from the customer may help to determine if the trouble
follows a pattern that is
temperature related.
- If temperature is suspected of causing an intermittent fault condition,
attempt to duplicate the
condition. Refer to Inducing Intermittent Fault Conditions in order to
duplicate the conditions
required.
Electromagnetic Interference and Electrical Noise
Some electrical components/circuits are sensitive to electromagnetic
interference or other types of
electrical noise. Inspect for the following conditions:
- A harness that is too close routed to high voltage/high current devices
such as secondary ignition
components, motors, generator etc. These components may induce electrical
noise on a circuit that
could interfere with normal circuit operation.
- Electrical system interference caused by a malfunctioning relay, or a
control module driven
solenoid or switch. These conditions can cause a sharp electrical surge.
Normally, the condition
will occur when the malfunctioning component is operating.
- Installation of non-factory or aftermarket add on accessories such as
lights, 2-way radios, amplifiers, electric motors, remote starters, alarm
systems, cell phones, etc. These accessories may create interference in
other circuits while operating and the interference would disappear when the
accessory is not operating. Refer to Checking Aftermarket Accessories.
- Test for an open diode across the A/C compressor clutch and for other
open diodes. Some relays
may contain a clamping diode.
- The generator may be allowing AC noise into the electrical system.
READ NEXT:
WARNING: Refer to Brake Fluid Irritant Warning.
CAUTION: Refer to Brake Fluid Effects on Paint and Electrical
Components Caution.
NOTE: Before performing the ABS Automated Bleed Procedure, first
per
Preliminary Procedure
Electronic Brake and Traction Control Module with Brake Pressure Modulator
Valve
Replacement (2.0L LTG) or Electronic Brake and Traction Control Module with
Brake
Pressure Mod
Preliminary Procedure
Electronic Brake and Traction Control Module with Brake Pressure Modulator
Valve
Replacement (2.0L LTG) or Electronic Brake and Traction Control Module with
Brake
Pressure Mod
SEE MORE:
Refer to the following sections for
important information on how to use
seat belts properly:
Seat Belts
How to Wear Seat Belts Properly
Lap-Shoulder Belt
Lower Anchors and Tethers for
Children (LATCH System)
Passenger Sensing System
The passenger sensing system
turns off the front outboar
WARNING: In order to reduce the risk of fire and personal injury
observe the
following items:
Replace all nylon fuel pipes that are nicked, scratched or damaged
during installation, do not attempt to repair the sections of the nylon
fuel pipes
Do not hammer directly on the fuel harness body cl