viperinadiper

Hey guys last night i was on my way home and i got the SERVICE TRACTION CONTROL and SERVICE ABS. Well this morning i went outside to pull the codes and here is what i got. And yes these are all current. Thanks.

28 TCS

C1235-RR WHEEL SPEED CIRCUIT OPEN OR SHORTED

C2120-TPM SYSTEM MALFUNCTION (NO SENSORS RECEIVED)

C2121-TPM SYSTEM PROGRAMMING MALFUNCTION (NO SENSORS PROGRAMMED).

Thanks for the help..

trussme

Perhaps one of the wheel speed sensors is either sending a bad signal or no signal. Start by checking the connections. The wheel speed sensors are integrated into the wheel bearing/hub assembly. The wire coming out of the back is the connection for the wheel speed sensors. Verify that the connector are not broken, damaged, or corroded in any way. Pay particular attention to the female end.
The wire coming out of the wheel speed sensor connects to and 18" jumper harness, then to the main harness. It is very common for people to have a weak female pin in one of those connections. If all of that checks out good, swap the jumper harness from side to side. For example if the left front is bad, swap it over to the right front. And install the good one from the right front to the left side. Then clear the trouble code. If the trouble code is now on the right side, you know the wire harness is the problem. If the code is still on the left side after swapping the jumper harnesses, you know the problem is inside the wheel speed sensors.
If all the wires check out good, it's time to take a trip to Auto Zone for a new set of bearings. You can buy replacement AC Delco bearing from your dealer if you want to, or get the exact same bearing in a different box for half the price (~$150) from Auto Zone, you decide. The bearings should be replaced in axel sets, so if your left front is bad, you have to replace the right front too. While you’re at it, this is a good time to upgrade the lug studs and add spindle ducts.

Tire Pressure Monitoring Sensor Programming

The Tire Pressure Monitor (TPM) system interfaces with the Instrument Panel Cluster (IPC) through the serial data line. Once the program mode is accessed through the IPC, each sensor's unique identification code can be programmed into the receiver's memory. Each sensor must transmit the unique code in the proper sequence. A magnet must be held close to the sensor in order to force the sensor to transmit the identification code. The IPC will display a message as each sensor is programmed, and when to proceed to the next sensor for programming. The receiver also sends a message to the BCM to sound the horn one time, indicating that the sensor properly transmitted an identification code. If the programming sequence is cancelled before any sensor is programmed, or if the vehicle's battery is disconnected, the receiver will remember all current identification codes. As soon as the receiver learns the first sensor identification code, all previously stored codes are erased from the receiver's memory.
J 41760 Tire Pressure Monitor (TPM) Programming Tool.
Tool required (any medium strength magnet, U or Disk type will work)

1) Turn ignition on 2) Press "Reset" button in order to clear any IPC display warning messages 3) Press and release the "Options" button on the DIC to scroll through the display options until the IPC display is blank 4) Press and hold the DIC "Reset" button for 3 seconds 5) Press the "Options" button again until TIRE TRAINING message appears 6) Press "Reset" button until the IPC "Learn L Front Tire" message appears in order to begin the programming 7) Install the J41760 Tire Pressure Monitor (TPM) System Programming Tool (large magnet will do) over the left front valve stem 8) The horn will sound, indicating the left front TPM sensor is programmed (if this takes more than 15 seconds, pull magnet back and try again, it will give you three tries. Then you must start over) 9) When the horn sounds, proceed to program the next TPM sensor in the following order as directed by the IPC messages: -Learn R Front Tire -Learn R Rear Tire -Learn L Rear Tire Programming can be canceled by turning ignition off, waiting 2 minutes with no sensors being learned, finishing all 4 wheels or through the DIC. If the programming is canceled with less than 4 sensors learned, it will only accept the codes programmed up to that point.


The Tire Pressure units in the tires have a small radio transmitter in them. They transmit 2 pieces of data ... the tire pressure, and the units unique serial number.

The radio transmissions are picked up by the RFA (Remote Function Actuator) which is a radio reciever that also picks up the transmissions from your key fobs. The data is then sent to the BCM from the RFA, and the BCM has the software that displays/alarms the tire pressure data.

When you move tires around on the car, and then go into TPMS "training" mode, the BCM displays a message to train the LF tire. The magnet you put near the tire stem wakes up the sensor and it transmits its serial number and tire pressure. The BCM then internally stores the information that that particular unit (serial number) is at the LF position. As you go round the car training the system, the BCM is simply "learning" the serial numbers of the sensors, and where they are located.

When the wheels stop turning, after a few minutes, the sensors go to "sleep" to conserve their internal batteries. When the wheels start turning again, the sensors wake up and start transmitting their serial number and pressure again. I believe they transmit several times a minute until the car has been stopped for a number of minutes (like 15 to 20).

MattB

I'd suggest adding the step of cleaning the gound points while your checking out the wiring near the bearings. Check the sticky on electrical info, it has great info on the ground points.