Diagnose and fix C0710, C0455 Service Stability
GM has issued a service bulletin PI0639C to address a service stability message and trouble codes C0710 and C0455 for the vehicles listed below. In addition to the information in the service bulletin, I’m adding more information on how the system works along with additional tips on how to diagnose problems
Vehicles with C0710, C0455 Service Stability issues
2007-2014 Cadillac Escalade Models
2007-2012 Chevrolet Colorado
2007-2013 Chevrolet Avalanche, Silverado 1500
2007-2014 Chevrolet Silverado HD, Suburban, Tahoe
2008-2016 Chevrolet Express
2007-2012 GMC Canyon
2007-2013 GMC Sierra 1500
2007-2014 GMC Sierra HD, Yukon Models
2008-2016 GMC Savana
What is a C0710 and C0455 trouble code?
These are “C” Chassis codes
C0710 Steering Position Signal Circuit Malfunction
C0455 Front steering position sensor circuit
What is a steering angle sensor?
The steering angle sensor (SWPS) is mounted in the steering column
and is part of the stability control system, which GM refers to as StabiliTrak®. The SWPS supplies Phase A and Phase B, Index Pulse Phase C circuits, and an Analog signal circuit for the steering wheel angle. These are all input signals to the electronic brake control module (EBCM).
The EBCM uses the analog signal and index pulse as calibrate for straight ahead position reference. The EBCM then uses the Phase A and Phase B signals to determine actual steering wheel deviation from the 0° position. Phase A and Phase B are approximately 90 degrees out of phase.
The SWPS must be calibrated any time you move the steering wheel while work on the steering steering system. Once calibrated, the EBCM interprets the relationship between the Phase A and Phase B inputs, and determines the exact position of the steering wheel and the direction of the steering wheel rotation. If the signals don’t match to what the EBCM expects, it’ll conduct additional tests and possibly set a trouble code for the SWPS
Diagnose C0710, C0455 Service Stability
Using a scan tool’s live data stream, check the SWPS Phase A and Phase B signals. The signals should toggle between High and Low as you turn the wheel
Next, check SWPS Phase A voltage. The value should be 2.5 volts when the wheels are pointed straight ahead and range from 0.8 to 3.8 volts as you turn the wheel.
Then check the Yaw sensor values. The yaw sensor detects deviation
from the vehicle’s angular velocity around its vertical axis. With the vehicle motionless, the Yaw rate sensor should read 2.5 volts.
Check the lateral accelerometer. This detects the amount of force in ft/lbs as the vehicle swings laterally during a skid. It should read 0 ft/lbs.
Drive the vehicle straight down the road and double check that the values reflect a straight ahead position at 2.5 volts.
Finally, verify that all tires are the same size and air pressure and width. A significant different in size or air pressure can trick the EBCM into thinking the vehicle has a wheel speed difference.
If all those items check out, proceed with the recommended GM fix.
Fix steering wheel position sensor connector
GM has determined that a loose connection or “fretting” can cause
an intermittent C0710, C0455 Service Stability condition. The advice is to remove the connector to the SWPS and use a nylon brush to apply dielectric grease to the terminals inside the connector and the SWPS. Next, add a small piece of adhesive backed shim stock to the entire width of the connector so it will fit more snugly into the SWPS, preventing the connector from moving up and down.
Clear the trouble codes and drive the vehicle.
©, 2017 Rick Muscoplat
Posted on by Rick Muscoplat