Code 43 - VES Steering Wheel Speed Sensor Circuit Malfunction: Notes

A 5-volt reference voltage is supplied to steering wheel speed sensor through EBCM steering wheel sensor VCC terminal. Steering wheel position input to EBCM is provided through steering wheel speed sensor to EBCM steering wheel sensor input terminal.

Code 43 can set anytime. A malfunction exists if steering wheel speed sensor voltage is less than .4 volts, greater than 4.67 volts or changes by greater than 2 volts in 8 milliseconds. Code will be stored, VES disabled and power steering returns to full assist.

NOTE: Test numbers refer to numbers on diagnostic chart. Use only 10-megohm (minimum) DVOM for all voltage and resistance tests. For identification of circuits and terminals referenced in charts and text, see WIRING DIAGRAM .

Fig 1: Code 43 Diagnostic Flow Chart - 1 Of 3

Courtesy of GENERAL MOTORS CORP.

Checks steering wheel speed sensor input to EBCM.
Checks for short between steering wheel sensor input and ground circuit.
Checks for short between steering wheel sensor VCC and ground circuit.
Checks for short to ground in steering wheel sensor input circuit.
Checks for short to ground in steering wheel sensor VCC circuit.
Checks for high resistance in steering wheel sensor VCC circuit.
Checks for high resistance in steering wheel sensor input circuit.
Checks for poor terminal contact.
Checks for poor voltage output of EBCM.
Ensures malfunction was not due to physical damage of steering wheel speed sensor circuits.