LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2011 >> Impala LS, 3.9 M >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 21 (Automatic Transmission - 4T65-E - DTC PO218 Through DTC P2534) >> DTC P0851 or P0852 >> Component Testing

Component Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, transmission in PARK, disconnect the automatic transmission 20-way inline connector.
  2. IMS - Install the J 44152  jumper harness (20 pins) on the transmission side of the automatic transmission 20-way inline connector. Using the J 35616  GM terminal test kit, measure the resistance between the park/neutral position signal circuit, pin W, and the ground circuit, pin K. The resistance should be less than 100 ohms. Repeat with transmission in NEUTRAL. See Special Tools .
    • If the resistance is less than the specified value, test the park/neutral signal circuit for an open, high resistance or short to ground. If the circuit tests normal, replace the ECM.
    • If the resistance is greater than the specified value, test the park/neutral signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  3. ECM - With the ignition ON and engine OFF, using a DMM and the J 35616  GM terminal test kit, measure the voltage between the park/neutral signal circuit, terminal W, on the engine side of the 20-way connector and chassis ground. The voltage should be 11.8-12.2 volts.
    • If the voltage is less than the specified range, test the park/neutral signal circuit for an open, high resistance, or short to ground. If the circuit tests normal, replace the ECM.
    • If the voltage is greater than the specified range, test the park/neutral signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
scientia non olet · About LEMON Manuals