Jeep Enthusiast Forums banner

ABS light stays on????

39K views 14 replies 9 participants last post by  justinleighton35 
#1 ·
Another question for you guys. After having the rear brakes and drums replaced due to the pad wearing into the drum $400, the mechanic said the right rear abs switch was damaged and needed to be replaced another $400. I told him to forget about it I would probably replace it myself. How much is the switch and is it hard to replace?

Thanks guys.
 
#3 ·
Actually, that is a Wheel Speed Sensor (WSS).
I have a sneaking suspicion your mechanic buddy cut the wire.
You are going to have to take a look at it yourself to determine what the damage is. If the wire is cut, you could simply solder and heat shrink it yourself. In which case the cost would be negligible.

A speed sensor is used at each whell. The front sensors are mounted to the steering knuckles. Ther rear sensors at the outboard end of the axle.
The sensors convert wheel speed into a small AC electrical signal. This signal is transmitted to the CAB (Controller Anti-lock Brake). The CAB converts the AC signal into a digital signal for each wheel. This voltage is generated by magnetic induction when a tone whell passes by the stationary magnetic of the wheel speed sensor.
A gear type tone ring serves as the trigger mechanism for each sensor. The tone rings are mounted at the outboard ends fo the front and rear axle shafts.
Different sensors are used at the front and rear wheels. The front/rear sensors have the same electrical values but are not interchangeable. The sensors have a resistance between 900 and 1300 ohms.
A rear sensor air gap adjustment is only needed when reinstalling an original sensor. Replacement sensors have an air gap spacer attached to the sensor pickup face. The spacer establishes correcgt air gap when pressed against the tone ring during installation. As the tone ring rotates, it peels the spacer off the sensor to create the required air gap. Rear sensor air gap is 0.92 - 1.45 mm (0.036 - 0.057 in.).
Rear Wheel Speed Sensor Removal
1) Raise and fold rear seat forward. Then move carpeting aside for access to rear sensor connectors.
2) Disconnect rear sensor wires at harness connectors.
3) Push sensor wires and grommets through floorpan holes.
4) Raise vehicle.
5) Remove wheel and brake drum.
6) Disengage sensor wire from axle and chassis brackets and from brakeline retainers.
7) Unseat sensor grommet from brake support plate.
8) Remove bolt attaching sensor to support plate bracket.
9) Remove sensor and wire through opening in support plate.
Installation
1) Insert sensor wire through support plate hole. Then seat sensor wire grommet in hole to secure wire.
2) Apply Loctite 242 to original sensor bolt. Use new bolt if original is worn or damaged.
3) Install sensor bolt finger tight only.
4) If original sensor is being installed or adjusted, remove any remaining pieces of cardboard spacer from sensor pickup face. Set air gap to 0.92-1.45 mm with feeler gauge. Tighten sensor bolt to 14 Nm (11 ft. lbs.).
5) If new sensor is being installed, push cardboard spacer on sensor face against tone ring. Then tighten sensor bolt to 11 ft. lbs. Correct air gap will be established as tone ring torates and peels spacer off sensor face.
6) Route sensor wires to rear seat area.
7) Feed sensor wires through floorpan access hole and seat sensor gormmets in floorpan.
8) Secure sensor wire in brackets and in retainers on your rear brakelines. Verify that sensor wire is secure and clear of rotating components.
9) Install brake drum and wheel and lower vehicle.
10) Fold rear seat and carpet forward for access to sensor wires and connectors.
11) Connect sensor wires to harness connectors.
12) Reposition carpet and fold rear seat down.
13) Visit destructive mechanic and present him with a bill for $400.00

HTH :thumbsup:
 
#4 ·
Do Jeeps have the system that requires a code reader? And if so wouldn't the faulty switch/sensor be detected ? Anyone know? :confused:
 
#5 ·
ABS Warning Lamp Display
The amber antilock lamp illuminates at startup as part of the system self check feature. The lamp illuminates for 1-3 seconds then goes off as part of the normal bulb check routine.
An ABS circuit fault is indicated when the amber lamp remains on after startup, or illuminates at any time during vehicle operation.
Verify that a fault is actually related to the ABS system before making any repairs. For example, if the red lamp illuminates but the amber ABS lamp does not, the problem is realted to a service brake component and not the ABS system. Or, if neither lamp illuminates but a brake problem is noted, again, the problem is with a service brake component and not with the ABS system.
DRB Scan Tool
ABS diagnosis is performed with the DRB scan tool Diagnosis information is provided in the Chassis Diagnostic Manual.
ABS Dignostic Connector
The ABS diagnostic connector is located inside the vehicle. The connector is the access point for the DRB scan tool.
The connector is blue or black in color and is a 6-way type. The connector is under the carpet at the froward end of the console ust under the IP center.

However, in TwistWrist6's case, the mechanic was working on the rear brakes. The mechanic informed TwistWrist6 he had a bad sensor. The red lamp came on.
Doesn't take a genius to figure that one out... :drool:

HTH :thumbsup:
 
#6 ·
Thanks guys once again you have proven the worth of this forum. Great tips!!!!

The only problem is I keep reading about more upgrades I can do to my jeep, 6" lifts, bull bars, superchargers, I want to do everything!!! I hate you guys for giving me ideas. The money you guys save me on repairs goes staight back into the jeep for upgrades!!! Did I mention I hate you guys? :D
 
#14 ·
My ABS light has been on for months following my inspection in AZ. Harbor Freight sells a Scan Tool that reviews say will diagnosis which wheel sensor is the bad on. I replaced my front sensors but still have a light. My frightening decision powers are now hung up on spending money on a set of rear sensors or the scan tool. Or just watch the light. I like amber. lol.
 
#15 ·
Thanks to this forum I was able to troubleshoot that problem. pull the connector off the ABS module it's to the right of your air filter. The pinout can be found on this forum you should be reading one kilo ohm on all of the ABS sensors. My front left was smashed by a rock. Also discovered my TPS and VSS sensors were toast hope to have the car Perfect by next week we'll post the results
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top