Download DTC C1233 RF Wheel Speed Circuit Open or Shorted

1999 Chevrolet/Geo Malibu
DTC C1233 RF Wheel Speed Circuit Open or Shorted
Circuit Description
As a toothed ring passes by the wheel speed sensor, changes in the electromagnetic field cause the wheel speed sensor
to produce an AC voltage signal. The frequency of the AC voltage signal is proportional to the wheel speed. The
amplitude of the AC voltage signal is directly related to wheel speed and the proximity of the wheel speed sensor to the
toothed ring. The proximity of the wheel speed sensor to the toothed ring is also referred to as the air gap.
Conditions for Setting the DTC
DTC C1233 can set anytime after initialization.
A malfunction exists if either of the right front wheel speed sensor circuits are open or shorted to voltage or ground.
Action Taken When the DTC Sets
z
z
z
A malfunction DTC stores.
The ABS disables.
The ABS warning indicator turns ON.
Conditions for Clearing the DTC
z
z
The condition responsible for setting the DTC no longer exists and the Scan Tool Clear DTCs function is used.
100 drive cycles pass with no DTCs detected. A drive cycle consists of starting the vehicle, driving the vehicle
over 16 km/h (10 mph), stopping and then turning the ignition OFF.
Diagnostic Aids
The following conditions may cause an intermittent malfunction:
z
z
z
A poor connection
Rubbed-through wire insulation
A broken wire inside the insulation
Use the enhanced diagnostic function of the Scan Tool in order to measure the frequency of the malfunction.
If the customer's comments reflect that the amber ABS warning indicator is ON only during moist environmental
changes (rain, snow, vehicle wash), inspect all the wheel speed sensor circuitry for signs of water intrusion. If the DTC
is not current, clear all DTCs and simulate the effects of water intrusion by using the following procedure:
1. Spray the suspected area with a five percent saltwater solution. Add two teaspoons of salt to twelve ounces of
water to make a five percent saltwater solution.
2. Test drive the vehicle over various road surfaces (bumps, turns, etc.) above 24 km/h (15 mph) for at least 30
seconds.
3. If the DTC returns, replace the suspected harness.
Thoroughly inspect any circuitry that may be causing the intermittent complaint for the following conditions:
z
z
z
z
z
z
Backed out terminals
Improper mating
Broken locks
Improperly formed or damaged terminals
Poor terminal-to-wiring connections
Physical damage to the wiring harness
Resistance of the wheel speed sensor will increase with an increase in sensor temperature.
Use the following procedure when replacing a wheel speed sensor or harness:
1. Inspect the wheel speed sensor terminals and harness connector for corrosion and/or water intrusion.
2. Replace the wheel speed sensor and jumper harness if evidence of corrosion or water intrusion exists. Refer to
On-Vehicle Service in this section.
Test Description
2. This test checks the wheel speed sensor circuitry for proper resistance values at the EBCM.
3. This test checks for a short to ground in the wheel speed sensor circuit.
4. This test checks for a short to voltage in either the high or the low wheel speed sensor signal circuits.
5. This test determines if the wheel speed sensor signal low is shorted to voltage.
6. This test determines if the wheel speed sensor signal high is shorted to voltage.
10. This test determines if the malfunction is caused by the EBCM.
11. This test checks for an open or high resistance in the wheel speed sensor signal low circuit.
12. This test checks for an open or high resistance in the wheel speed sensor signal high circuit.
13. This test checks the wheel speed sensor for the proper resistance value.
14. This test checks for a short to ground in the wheel speed sensor signal low circuit.
15. This test checks for a short to ground in the wheel speed sensor signal high circuit.
16. This test checks for an intermittent short to ground in the wheel speed sensor signal high circuit.
17. This test checks for an intermittent short to ground in the wheel speed sensor signal low circuit.
18. This test checks for a short to ground in the wheel speed sensor.
Step
Important
Action
Value(s)
Yes
No
Zero the J 39200 test leads before making any resistance measurements. Refer to the J 39200 user's manual.
Important
Difficulty may occur when trying to locate intermittent malfunctions in the wheel speed sensor circuit.
Do not disturb any of the electrical connections. Change the electrical connections only when instructed to do so by a
step in the diagnostic table.
Changing the electrical connections at the correct time will ensure that an intermittent electrical connection will not
be corrected until the source of the malfunction is found.
Was the ABS Diagnostic System Check performed?
Go to Diagnostic
1
-System Check Go to Step 2
ABS
1. Turn the ignition switch to the OFF position.
2. Make a 5 percent saltwater solution.
3. Thoroughly spray the right front wheel speed sensor
harness with the saltwater solution.
4. Disconnect the EBCM harness connector.
10402
5. Use the J 39200 in order to measure the resistance
1160 ohms
between the EBCM harness connector terminal 9 and
the EBCM harness connector terminal 22.
3
4
5
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the EBCM harness connector terminal 22 and ground.
Is the resistance within the specified range?
1. Turn the ignition switch to the ON position. Do not start
the engine.
2. Use the J 39200 in order to measure the voltage
between the EBCM harness connector terminal 22 and
ground.
Is the voltage within the specified range?
1. Turn the ignition switch to the OFF position.
2. Disconnect the right front wheel speed sensor at the
right front wheel speed sensor connector.
3. Turn the ignition switch to the ON position. Do not start
the engine.
4. Use the J 39200 in order to measure the voltage
between the EBCM harness connector terminal 22 and
Go to Step 3
Go to Step 11
Go to Step 4
Go to Step 14
Go to Step 7
Go to Step 5
OL
(Infinite)
0-1 V
0-1 V
ground
6
7
Is the voltage within the specified range?
Use the J 39200 in order to measure the voltage between the
EBCM harness connector terminal 9 and ground.
Is the voltage within the specified range?
1. Turn the ignition switch to the OFF position.
2. Inspect the following terminals:
{ The EBCM connector terminal 9
{ The EBCM connector terminal 22
{ The remaining terminals of the EBCM connector.
3. Inspect the above terminals for the following
conditions:
{ Terminal damage
{ Poor terminal contact
{ Terminal corrosion Terminal damage, terminal
corrosion, and poor terminal contact may cause
an open circuit, a short to voltage, or a short to
ground.
Go to Step 6
Go to Step 19
Go to Step 31
Go to Step 20
Go to Step 27
Go to Step 8
Go to Step 21
Go to Step 9
Go to Step 22
Go to Step 10
0-1 V
--
Are there signs of poor terminal contact, terminal corrosion,
or damaged terminals?
Inspect the wiring of CKT 833 and CKT 872 for signs of wire
damage.
Wire damage may cause the following conditions in CKT 833
and CKT 872:
8
-z
z
z
An open circuit
A short to voltage
A short to ground
Are there signs of damaged wiring?
Inspect the harness connectors of CKT 833 and CKT 872 for
signs of wire damage.
Wire damage may cause the following conditions in CKT 833
and CKT 872:
9
-z
z
z
An open circuit
A short to voltage
A short to ground
Are there signs of damaged connectors?
1. Reconnect the EBCM connector.
2. Reconnect the right front wheel speed sensor harness
connector.
3. Install a Scan Tool .
10
4. Test drive the vehicle at a speed above 24 km/h
(15 mph) for at least 30 seconds.
5. Use the Scan Tool in order to read the DTCs.
--
Does DTC C1233 set as a current DTC?
1. Disconnect the right front wheel speed sensor directly at
the right front wheel speed sensor connector.
2. Use the J 39200 in order to measure the resistance
1040between the EBCM connector terminal 22 and the right
11
1160 ohms
front wheel speed sensor harness connector terminal B.
Go to Step 30
Go to Step 31
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the EBCM connector terminal 9 and the right front wheel
12 speed sensor harness connector terminal A.
Go to Step 12
Go to Step 23
Go to Step 13
Go to Step 24
Go to Step 31
Go to Step 28
Go to Step 15
Go to Step 25
Go to Step 16
Go to Step 26
Go to Step 17
Go to Step 29
Go to Step 18
Go to Step 29
Go to Step 31
Go to Step 28
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the right front wheel speed sensor connector terminal A and
13 the right front wheel speed sensor connector terminal B.
14
15
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the EBCM connector terminal 22 and ground.
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the EBCM connector terminal 9 and ground.
Is the resistance within the specified range?
1. Thoroughly respray the right front wheel speed sensor
harness with the saltwater solution.
2. Disconnect the right front wheel speed sensor directly at
the right front wheel speed sensor.
3. Use the J 39200 in order to measure the resistance
16
between the right front wheel speed sensor harness
connector terminal A and ground.
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the right front wheel speed sensor harness connector
17 terminal B and ground.
10401160 ohms
10401160 ohms
OL
(Infinite)
OL
(Infinite)
OL
(Infinite)
OL
(Infinite)
Is the resistance within the specified range?
Use the J 39200 in order to measure the resistance between
the right front wheel speed sensor connector terminal A and
18 ground.
Is the resistance within the specified range?
Repair the short to voltage in CKT 833. Refer to Wiring
Repairs in Wiring Systems.
19 If the short to voltage is found in the right front wheel speed
sensor harness, replace the right front wheel speed harness.
Refer to Wheel Speed Sensor Jumper Harness Replacement .
OL
(Infinite)
-Go to Diagnostic
System Check -
Is the repair complete?
Repair the short to voltage in CKT 872. Refer to Wiring
Repairs in Wiring Systems.
20
If the short to voltage is found in the right front wheel speed
sensor harness, replace the right front wheel speed harness.
Refer to Wheel Speed Sensor Jumper Harness Replacement .
If the wiring damage is found in the right front wheel speed
sensor harness, replace the right front wheel speed harness.
Refer to Wheel Speed Sensor Jumper Harness Replacement .
If the short to ground is found in the right front wheel speed
sensor harness, replace the right front wheel speed harness.
Refer to Wheel Speed Sensor Jumper Harness Replacement .
Is the repair complete?
Repair the short to ground in CKT 872. Refer to Wiring
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
--
Is the repair complete?
Repair the short to ground in CKT 833. Refer to Wiring
Repairs in Wiring Systems.
25
Go to Diagnostic
System Check ABS
--
Is the repair complete?
Repair the open or high resistance in CKT 872. Refer to
Wiring Repairs in Wiring Systems.
If the open or high resistance is found in the right front wheel
24 speed sensor harness, replace the right front wheel speed
harness. Refer to Wheel Speed Sensor Jumper Harness
Replacement .
--
--
Is the repair complete?
Repair the open or high resistance in CKT 833. Refer to
Wiring Repairs in Wiring Systems.
If the open or high resistance is found in the right front wheel
23 speed sensor harness, replace the right front wheel speed
harness. Refer to Wheel Speed Sensor Jumper Harness
Replacement .
Go to Diagnostic
System Check ABS
--
Is the repair complete?
Repair the connector damage in CKT 833 or CKT 872. Refer
to Wiring Repairs in Wiring Systems.
If the connector damage is found in the right front wheel
22 speed sensor harness, replace the right front wheel speed
harness. Refer to Wheel Speed Sensor Jumper Harness
Replacement .
--
--
Is the repair complete?
Repair the wiring damage in CKT 833 or CKT 872. Refer to
Wiring Repairs in Wiring Systems.
21
ABS
--
Repairs in Wiring Systems.
If the short to ground is found in the right front wheel speed
26 sensor harness, replace the right front wheel speed harness.
Refer to Wheel Speed Sensor Jumper Harness Replacement .
Is the repair complete?
Replace all of the terminals and the connectors that exhibit
signs of poor terminal contact, corrosion, or damaged
27 terminals. Refer to Wiring Repairs in Wiring Systems.
28
29
30
Is the repair complete?
Replace the right front wheel speed sensor. Refer to Wheel
Speed Sensor Replacement .
Is the repair complete?
Replace the right front wheel speed sensor harness. Refer to
Wheel Speed Sensor Jumper Harness Replacement .
Is the repair complete?
Replace the EBCM. Refer to Electronic Brake Control
Module (EBCM) Replacement .
Is the repair complete?
z The malfunction is intermittent or not present at this
time.
z Inspect all of the connectors and the harnesses for
damage that could cause the following conditions:
{ An open or a high resistance
{ A short to ground
31
{ A short to voltage
z The sensor harness must be replaced if the sensor
harness is damaged.
z Refer to Diagnostic Aids for more information.
Is the action complete?
--
--
--
--
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
Go to Diagnostic
System Check ABS
--
System OK
--
--