Code A051: Excessive Left Rear Wheel Speed Acceleration

Wheel sensors generate voltage signals as the wheel rotates. The created frequency enables the anti-lock brake controller to determine wheel RPM. If the information received is not within preset values, the anti-lock brake controller determines signal is faulty and will set Code A051. To set Code A051, the following conditions must occur.

• Brakes are not applied (brake switch off).
• Anti-lock brake controller senses illogical left rear wheel speeds.

1. Observe left rear wheel speed input to determine what type of input the anti-lock brake controller is sensing. Erratic or unsteady readings indicate a continuous malfunction in wheel speed sensor. Stable readings indicate problem is intermittent.
2. Indicates a short to battery.
3. If voltage is present, a short exists in the anti-lock brake controller or wire harness.
4. If 9000-15,000 ohms are measured, circuit between anti-lock brake controller and connector C164 is okay.
5. If 10 ohms or more are measured, circuit between anti-lock brake controller and connector C164 is okay. Inspect for fault between wheel speed sensor and connector C164.
6. If 1500-2500 ohms are measured, a short to ground exists. If more than 2500 ohms are measured, an open condition exists. If less than 1500 ohms are measured, a shorted sensor circuit is indicated.
7. Isolates fault to either wire harness or wheel speed sensor. Harness must be replaced (not repaired) if defective.
8. Isolates fault to either wire harness or wheel speed sensor. Harness must be replaced (not repaired) if defective.
9. Circuit No. 884 is connected to ground. If infinite resistance is measured, an open condition exists in circuit No. 884.
10. Circuit No. 885 is connected to ground. If infinite resistance is measured, an open condition exists in circuit No. 885.