Model All Model
Group Suspension System(21)
Date Tuesday, September 23, 2008
Area N. America
Subject Diagnosing Low Line TPMS
Diagnosing Low Line TPMS
Diagnosing TRW/Lear Low Line Tire Pressure Monitoring warning light ON conditions with certain Diagnostic Trouble Codes stored in Memory requires particular attention. The following procedure can assist in proper diagnosis for the wheel sensor concerns.
Install TPMS tool to diagnose DTC's, retrieve DTC C1313, C1312, etc.
Select "Current Data" on the TPMS tool.
Using the worksheet record sensor ID for all Four (4) Sensors from the "Current data" Screen.
Ping each wheel and record these sensor ID's on the worksheet.
Match wheel sensor ID, against the ID recorded from the exciter tool/ECU. The missing sensor ID should be checked for correct setting and battery level, replace sensor if necessary.
DO NOT replace or diagnose components in a position based on the DTC information. Always locate the sensor ID on the vehicle with the hand-tool. A commen mistake is Code C1312 is set and the technical replaces that sensor thinking it was in the left Front, the wheel and tire may be located in the Right Rear. When and it the tires are rotated the original configuration is no longer valid.
TPMS Wheel Sensor Worksheet
If the Lamp shown above is ON: Check tire pressure and check for causes of low pressure.
If the Lamp shown above is ON:
Verify wheel sensor ID's in the ECU module corresponds to all 4 sensors on the vehicle - if not, reprogram the sensors on the vehicle into the ECU module.
Verify that the ECU module and all 4 wheel sensors have the mode and state configured correctly - if not, correct this condition first. - This applies to TRW systems only.
Examine for possible system interference from:
Some Cell Phone Chargers
Some Laptop Computers and power inverters
Exciter tool connected while driving the vehicle
Navigational Devices (GPS)
Aftermarket RKE, Buglar Alarm, Remote Start Systems
HAM radio equipment
High Tension Power Lines and Radio Station Towers
Anti-Theft Auto locating Devices
Portable DVD Players, portable MP3 players
Incorrect Instrument Cluster - Part application not corrected
Excessive aftermarket wiring tie-wrapped and coiled on or near TPMS module. This may create a magnetic field causing concern.
If all wheel sensor ID's, Mode and State are correct as initially received and you cannot identify any interfearence as listed above and the problem persists, replace the correct ID as reported by the ECU.
Wheel sensor to ECU communication takes place every 3 minutes, 20 seconds for TRW systems and every 3 minutes for Lear systems unless rapid tire deflation is occuring. Be sure to wait this amount of time for the values to populate on the Current Data Screen.
To verify your repair drive the vehicle at or above 20 MPH for 20 minutes, if speed goes below 20 MPH during Auto-Learn (TRW only), the process is halted until speed is above threshold again.
Auto-Learn (TRW only), is not recommended, use exciter tool each time to program the sensor ID's into the receiver module.
TPMS Drive Cycle
The warning light shown above = indicates Low tire pressure problem, use exciter tool and match tire pressure on-screen value against your tire pressure gauge reading. The tire pressures should be set COLD.
Inaccurate tire gauges should be replaced immediately to prevent comebacks.
The warning light shown above = indicates a problem with the Wheel sensors, TPMS module, radio frequency interfearence or related wiring. Use Exciter too to diagnose.
Friday, March 22nd, 2013 AT 1:27 AM