DTC C1171-C1174

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. DTC Descriptor DTC C1171 49 Tire Pressure Monitoring Sensor = Left Front Internal Electronic Failure DTC C1172 49 Tire Pressure Monitoring Sensor = Right Front Internal Electronic Failure DTC C1173 49 Tire Pressure Monitoring Sensor = Left Rear Internal Electronic Failure DTC C1174 49 Tire Pressure Monitoring Sensor = Right Rear Internal Electronic Failure Circuit/System Description For an overview of the component/system, refer to: Tire Pressure Monitor Description and Operation Conditions for Running the DTC Ignition On/Vehicle in Service Mode. Ignition Voltage 9–16 volts. TPMS Sensors are properly learned. Conditions for Setting the DTC Too Few Pulses: The BCM receives no or invalid data from a sensor for 17 minutes with vehicle speed between 40 km/h (25 mph) and 250 km/h (155 mph). Action Taken When the DTC Sets The tire pressure monitor indicator icon on the instrument panel cluster (IPC) flashes 60 to 90 seconds and then remains illuminated after the ignition switch is cycled ON and the IPC bulb check is complete. If equipped, the DIC displays a service tire monitor type message and dashes will only appear for the particular corner that triggered the failure. Conditions for Clearing the DTC Too Few Pulses: A valid transmission is received from the faulty corner. A history DTC will clear after 40 ignition cycles. Diagnostic Aids If all 4 sensors fault DTC are set and DTC U0214 Lost Communication with Remote Function Actuator Module is also set then diagnose Remote Function Actuator Module communication failure. Some aftermarket wheel valve stem holes are located further away from the wheel rim than on original equipment wheels. When using the tire pressure monitor tool to activate a sensor, ensure the tool is placed along the tire sidewall close to the sensor and not on the rim. If a sensor is not recognized, it may help to rotate the wheel so that the sensor is in a different position relative to the vehicle. A sensor may have been damaged by a previous wheel/tire service or flat tire event Occasionally sensor transmissions are not received by the control module due to radio interference from internal (aftermarket ignition systems, DVD players, CB radios, traffic video cameras, or metallic type window tinting) or external RF sources. Before a defective sensor is replaced, execute the learn procedure for all sensors to make sure the DTC was set for the correct position on the vehicle. The wheels may have been exchanged before without learning the new positions. Aftermarket wheel valve stem locations can cause a sensor to not function correctly. The use of tire sealants can obstruct the sensor pressure sensing port and cause inaccurate tire pressure readings. If this condition is verified, remove the sealer from the tire and replace the sensor. Refer to: Tire Pressure Indicator Sensor Replacement The sensor activation procedure may have to be repeated up to 3 times before determining a sensor is malfunctioning. In the event a particular sensor is not learned and the horn does not chirp, it may be necessary to rotate the wheel to a different position due to the RF signal being blocked by another component. Occasionally, sensors can become mislocated due to previous tire rotations where the sensor learn procedure was not performed. Always learn the sensors to ensure the DTC set is for that actual physical corner of the vehicle. Perform the following learn procedure: Tire Pressure Indicator Sensor Learn. Reference Information Scan Tool Reference Control Module References for scan tool information Circuit/System Verification With Available EL-52545 Tool Perform the following learn procedure: Tire Pressure Indicator Sensor Learn. Without Available EL-52545 Tool

1. Verify there are no other DTCs set, except for DTC C1171, C1172, C1173 or C1174. ⇒ If any other DTCs are set Refer to Diagnostic Trouble Code (DTC) List - Vehicle. ⇓ If no other DTCs are set
2. Verify the scan tool Tire Pressure Sensor Timer parameter of all 4 tire pressure sensors is communicating maximum of 300 s and not rising while driving the vehicle above 40 km/h (25  mph) for greater than 5 min.

Note

All TPM sensors should display a saw-tooth wave form that returns to zero, ideally each 60 seconds (or 10 seconds for a period after a relearn).  If any timer reaches 1020 seconds a “too few pulses” code will set.  It is not unusual for transmissions to occasionally be missed due to many factors, however if an individual location is growing to 300-500 seconds there is likely something faulty or interfering with this transmission. In this event, one should rotate and relearn the tires and then reevaluate.  If the same wheel, in the new position continues to infrequently reset to zero - growing to 300-500 seconds replace the TPM Sensor in that wheel. If the large accumulation of seconds remains in the same vehicle position after the rotation, the fault is likely due to a radio frequency interference. Refer to Diagnostic Aids. ⇒ If the Tire Pressure Sensor Timer parameter is not communicating maximum of 300 s and rising on one or more tires 2.1. Move the appropriate tire to a different location on the vehicle if possible or swap the two components, the original component that is not responding with another known good component from the vehicle and verify the Tire Pressure Sensor Timer is communicating maximum of 300 s and not rising. Refer to Tire and Wheel Removal and Installation. ⇒ If Tire Pressure Sensor Timer parameter does not communicate maximum of 300 s and rising after moving tire or component to different location, replace the appropriate B2  Tire Pressure Sensor and perform the Tire Pressure Indicator Sensor Learn. ⇒ If Tire Pressure Sensor Timer parameter does communicate maximum of 300 s and not rising after moving tire or components to different location, check for any aftermarket devices that could be causing interference to the tire pressure sensor signal. ⇓ If the Tire Pressure Sensor Timer parameter is communicating maximum of 300 s and not rising on one or more tires

3. Perform the Tire Pressure Indicator Sensor Learn.
4. Verify the scan tool Tire Pressure Sensor Mode parameter changes to Drive while driving the vehicle above 40 km/h (25 mph) for greater than 2 min. ⇒ If a Tire Pressure Sensor Mode parameter does not change to Drive 4.1. Replace the appropriate B2 Tire Pressure Sensor. 4.2. Perform the Tire Pressure Indicator Sensor Learn. ⇓ If the Tire Pressure Sensor Mode parameter does change to Drive
5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. If the sensors are not able to learn, they will need to be replaced. Refer to: Tire Pressure Indicator Sensor Replacement