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ABS PROBLEMS HELP!!!
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Re: ABS PROBLEMS HELP!!!
Re: ABS PROBLEMS HELP!!!
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal-to-wiring connections
- Physical damage to the wiring harness
? The following conditions may cause an intermittent malfunction:
- A poor connection
- Rubbed-through wire insulation
- A broken wire inside the insulation
? If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections .
The number below refers to the step number on the diagnostic table.
Step
Action
Value(s)
Yes
No
Schematic Reference: Antilock Brake System Schematics
Connector End View Reference: Antilock Brake System Connector End Views
1
Did you perform the Diagnostic System Check - Vehicle?
--
Go to Step 2
Go to Diagnostic System Check - Vehicle
2
Did you find and correct the condition?
--
Go to Step 8
Go to Step 3
3
Does the resistance measure less than the specified value?
5 Ω
Go to Step 4
Go to Step 5
4
Inspect for poor connections at the pump motor harness pigtail connector of the BPMV. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.
Did you find and correct the condition?
--
Go to Step 8
Go to Step 6
5
Inspect for poor connections at the harness connector of the EBCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs.
Did you find and correct the condition?
--
Go to Step 8
Go to Step 7
6
Replace the BPMV. Refer to Brake Pressure Modulator Valve Replacement.
Did you complete the repair?
--
Go to Step 8
--
7
Replace the EBCM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the repair?
--
Go to Step 8
--
8
Does the DTC reset?
--
Go to Step 2
System OK
1987 Jeep YJ 403hp sbc 653hp on NOS
1998 Chev Z71
2007 Chev Trailblazer SS
Re: ABS PROBLEMS HELP!!!
<A href="#ss1-1392930">Circuit Description
The speed sensors used on the front of this vehicle are multiple pole and the rear uses a single pole magnetic pickup. This sensor produces an AC signal that the EBCM uses the frequency from to calculate the wheel speed.
<A href="#ss2-1392930">DTC Descriptor
This diagnostic procedure supports the following DTCs:
DTC C0245 Wheel Speed Sensor Frequency Error
<A href="#ss3-1392930">Conditions for Running the DTC
? The DTC can be set after system initialization.
? The EBCM detects a deviation between the left and right front wheel speeds of greater than 10 km/h (6.25 mph) at a vehicle speed of less than 100 km/h (62 mph).
? The EBCM detects a deviation between the left and right front wheel speeds of greater than 4 km/h (2.5 mph) plus 6 percent of the vehicle speed at greater than 100 km/h (62 mph).
<A href="#ss5-1392930">Action Taken When the DTC Sets
If equipped, the following actions occur:
? A malfunction DTC will set.
? The ABS indicator turns ON.
? The traction control system (TCS) indicator turns ON.
? The Red BRAKE Warning indicator turns ON.
? The electronic brake control module (EBCM) automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
? Thoroughly inspect any circuitry that may be causing the complaint for the following conditions:
- Backed out terminals
- Improper mating
- Broken locks
- Improperly formed or damaged terminals
- Poor terminal-to-wiring connections
- Physical damage to the wiring harness
? The following conditions may cause an intermittent malfunction:
- A poor connection
- Rubbed-through wire insulation
- A broken wire inside the insulation
? If the customer's comments reflect that the amber ABS/TCS indicator is on only during moist environmental conditions (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.
3. If the DTC returns, replace the suspected harness.
? If an intermittent malfunction exists refer to Testing for Intermittent Conditions and Poor Connections .
The numbers below refer to the step numbers on the diagnostic table.
<A name=TD07>
<A name=TD09>
1987 Jeep YJ 403hp sbc 653hp on NOS
1998 Chev Z71
2007 Chev Trailblazer SS
Re: ABS PROBLEMS HELP!!!
Action
Yes
No
Schematic Reference: Antilock Brake System Schematics
Connector End View Reference: Antilock Brake System Connector End Views
1
Did you perform the Diagnostic System Check - Vehicle?
Go to Step 2
Go to Diagnostic System Check - Vehicle
2
Is the following DTCs set concurrently with a history DTC C0245?
? DTC C0041
? DTC C0046
? DTC C0051
Go to Step 3
3
Inspect the wheel speed sensor (WSS) for physical damage.
Is physical damage of the WSS evident?
Go to Step 4
Go to Step 5
4
Replace the WSS. Refer to Front Wheel Speed Sensor Replacement or Rear Wheel Speed Sensor Replacement .
Is the replacement complete?
Go to Step 14
--
5
Inspect the wiring harness for physical damage.
Is physical damage of the wiring harness evident?
Go to Step 6
Go to Step 7
6
Repair the wiring harness. Refer to Wiring Repairs and Connector Repairs .
Is the replacement complete?
Go to Step 14
--
7
Check for proper routing of the wheel speed sensor harness. Check that the wheel speed sensor harness is routed away from the spark plug wires. Refer to Harness Routing Views .
Is the wheel speed sensor harness properly routed?
Go to Step 9
Go to Step 8
8
Reroute the wheel speed sensor harness away from the spark plug wires.
Is the reroute complete?
Go to Step 14
--
9
Did the scan tool trigger on any of the wheel speed sensors?
Go to Step 10
Go to Step 11
10
Note which wheel speed sensor triggered the scan tool. Follow the appropriate Wheel Speed Sensor Malfunction DTC table for the wheel speed sensor that triggered. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
Is the repair complete?
Go to Step 14
--
11
Does the DTC reset as a current DTC?
Go to Step 13
Go to Step 12
12
Malfunction is intermittent. Inspect all connectors and harnesses for damage that may result in an open or high resistance when connected. Refer to Connector Repairs and Wiring Repairs .
Is the repair complete?
Go to Step 14
--
13
Replace the electronic brake control module (EBCM). Refer to Control Module References for replacement, setup, and programming.
Is the replacement complete?
Go to Step 14
--
14
Does the DTC reset?
Go to Step 2
System OK
1987 Jeep YJ 403hp sbc 653hp on NOS
1998 Chev Z71
2007 Chev Trailblazer SS
Re: ABS PROBLEMS HELP!!!
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