Chevrolet Trax: DTC C0775: Tire pressure monitoring system sensors
malfunction
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 C0775 00
Tire Pressure Monitoring System Sensors Malfunction
Circuit/System Description
If the body control module (BCM) has been reprogrammed or replaced and the
tire pressure sensor learn
procedure has not been performed, the tire pressure monitor system indicator
icon on the instrument cluster will
flash for 1 min and then remain illuminated after the power switch is cycled ON
and the instrument cluster bulb
check is complete. If equipped, the driver information center will also display
a service tire monitor type
message. Under these circumstances, DTC C0775 will be set in the BCM and the
tire pressure sensor learn
procedure will need to be performed for the system to function correctly.
Conditions for Running the DTC
Vehicle ON or Vehicle in Service Mode.
Conditions for Setting the DTC
The body control module (BCM) has not learned tire pressure sensor ID and
location information from the tire
pressure sensors.
Action Taken When the DTC Sets
- The tire pressure monitor system indicator icon on the instrument
cluster will flash for 1 min and then
remain illuminated after the power switch is cycled ON and the instrument
cluster bulb check is
complete.
- If equipped, the driver information center displays a service tire
monitor type warning message.
Conditions for Clearing the DTC
A current DTC will clear when the BCM has received tire pressure sensor ID
and location information from the
tire pressure indicator module and at least 1 power switch cycle has occurred.
Reference Information
Description and Operation
Tire Pressure Monitor Description and Operation
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
- Perform the Tire Pressure Indicator Sensor Learn.
- Verify DTC C0775 is not set.
Replace the K9 Body Control Module.
- All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for BCM replacement, programming, and setup.
SYMPTOMS - TIRE PRESSURE MONITORING
- Perform the Diagnostic System Check - Vehicle , before using the Symptom
Tables in order to verify
that all of the following are true:
- There are no DTCs set.
- The control modules can communicate via the serial data link.
- Review the system operation in order to familiarize yourself with the
system functions. Refer to Tire
Pressure Monitor Description and Operation.
Visual/Physical Inspection
- Inspect for aftermarket devices which could affect the operation of the
Tire Pressure Monitoring (TPM)
System. Refer to Checking Aftermarket Accessories .
- Inspect the easily accessible or visible system components for obvious
damage or conditions which could
cause the symptom.
Intermittent
Faulty electrical connections or wiring may be the cause of intermittent
conditions. Refer to Testing for
Intermittent Conditions and Poor Connections
Symptom List
Refer to Low Tire Pressure Indicator Malfunction in order to diagnose the
symptom.
LOW TIRE PRESSURE INDICATOR MALFUNCTION
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.
Circuit/System Description
The tire pressure monitor system has a radio frequency transmitting pressure
sensor in each wheel/tire
assembly. As vehicle speed increases, centrifugal force closes the sensors
internal roll switch, which puts the
sensor into Drive mode. The sensors send the tire pressure data to the body
control module (BCM). The BCM
translates the data contained in the tire pressure sensor radio frequency
transmissions into sensor presence,
sensor mode, and tire pressure. Once vehicle speed is greater than 40 km/h (25
MPH), the BCM waits for the
sensors to go into Drive mode.
Each sensor has its own unique identification (ID) code, which it transmits as
part of each RF message, that
must be learned into the BCM memory. Once all 4 IDs have been learned and
vehicle speed is greater than 40
km/h (25 mph), the BCM continuously compares IDs and pressure data in the
received transmissions to the
learned IDs and pressures to determine if all 4 sensors are present and if one
or more tires are low. If the BCM detects a low tire pressure
condition or a malfunction in the system, it will send a serial data message to
the
instrument cluster requesting the appropriate tire pressure monitor indicator
illumination and also to display the
appropriate data message on the driver information center, if equipped.
Diagnostic Aids
- If unsure about the condition, cycle the ignition and observe the tire
pressure monitor indicator icon. If
the tire pressure monitor indicator icon is continuously illuminated after
the instrument cluster bulb check
is completed, a low tire pressure condition is present. Check the tires for
damage or leaks and inflate to
the tire placard specifications. Refer to Vehicle Certification, Tire
Placard, Anti-Theft, and Service
Parts ID Label , . If the tire pressure monitor indicator icon flashes for 1
min after the instrument cluster
bulb check is completed and then remains illuminated, a tire pressure
monitor system DTC is set. Perform
the Diagnostic System Check - Vehicle to proceed with the proper diagnosis.
- Temperature can greatly effect tire pressures. Low tire pressure on a
cold morning may cause the tire
pressure monitor indicator icon to turn ON. The air pressure in the tire
increases as the ambient
temperature rises or as the tire warms up while the vehicle is driven. The
pressure may increase enough to
exceed the predetermined low pressure threshold which will turn OFF the tire
pressure monitor indicator
icon .
- Some aftermarket wheel valve stem holes are located further from the
wheel rim than original equipment
wheels. When using the tire pressure monitor special tool to activate a
sensor, ensure the tool antenna is
no further than 15 cm (6 in) from the sensor and is aiming upward.
- Aftermarket wheel value stem locations can cause a sensor to not
function correctly.
- A sensor may have been damaged due to a previous wheel/tire service or
flat tire event.
- The use of other than GM approved 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's information is displayed
on the special tool upon
activation but the horn does not chirp, it may be necessary to rotate the
wheel valve stem to a different
position due to the RF signal is being blocked by another component.
- Occasionally sensor transmissions are not received by the BCM due to
vehicle level RF interference from
items such as but not limited to aftermarket ignition systems, DVD players,
CB radios, or metallic type
window tinting.
Reference Information
Description and Operation
Tire Pressure Monitor Description and Operation
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
NOTE:
- Low tire pressure in one or more tires is indicated by a continuously
illuminated
tire pressure monitor indicator icon after the instrument cluster bulb check
is
completed. If equipped with a driver information center, a check tire
pressure
type message will also be displayed.
- When a tire pressure monitor DTC is set, the tire pressure monitor
indicator
icon will flash for 1 min after the instrument cluster bulb check is
completed
and then remains illuminated. If equipped with a driver information center,
a
service tire monitor type message will also be displayed.
- Adjust all tire pressures to the correct pressure. Refer to Vehicle
Certification, Tire Placard, Anti-
Theft, and Service Parts ID Label .
- Drive the vehicle over 40 km/h (25 mph) for greater than 2 min.
- Verify the low tire pressure indicator is OFF.
- If the low tire pressure indicator is ON
- Perform the Tire Pressure Indicator Sensor Learn.
- Record all 4 Tire Pressure Parameters values from the scan tool.
- Check and record the tire pressures with a known accurate hand held tire
pressure gauge.
- Verify that the scan tool Tire Pressure parameters do not differ more
than 27.6 kPa (4 psi) from the
actual tire pressure readings.
- If the scan tool Tire Pressure parameters differ more than 27.6 kPa (4
psi), replace the
appropriate B2 Tire Pressure Sensor then perform the Tire Pressure Indicator
Sensor
Learn.
- If the scan tool Tire Pressure parameters do not differ more than 27.6
kPa (4 psi)
- Verify the BCM Tire Type and Pressure selections are setup correctly
with a scan tool. Refer to the
Vehicle Certification, Tire Placard, Anti-Theft, and Service Parts ID Label
.
- If the BCM Tire Type and Pressure selections are incorrect, input the
proper placard values
for the vehicle with the scan tool then drive the vehicle over 40 km/h (25
mph) for greater
than 2 min.
- If the BCM Tire Type and Pressure selections are correct
- Ignition ON.
- Verify the low tire pressure monitor indicator icon turns ON and OFF
when commanding All
Indicators ON and OFF with a scan tool.
- If the low tire pressure monitor icon does not turn ON and OFF, replace
the P16 Instrument
Cluster.
- If the low tire pressure monitor icon turns ON and OFF
- All OK
- If the tire pressure indicator is OFF
All OK
- If the tire pressure indicator is OFF
- All OK
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Tire Pressure Indicator Sensor Replacement
- Tire Pressure Indicator Sensor Learn
- Control Module References for instrument cluster or BCM replacement,
programming, and setup.
READ NEXT:
Removal Procedure
Raise the vehicle on a suitable support. Refer to Lifting and Jacking
the Vehicle .
Remove the tire/wheel assembly from the vehicle. Refer to Tire and Wheel
Removal and Instal
Special Tools
EL-46079 Tire Pressure Monitor Diagnostic Tool
EL-50448 Tire Pressure Monitor Sensor Activation Tool
For equivalent regional tools, refer to Special Tools.
Learn Mode Description
The
SEE MORE:
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
DT
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
DT