Circuit/System Testing
WARNING: This page is about a different car, the 2009 GMC Sierra, 2009 GMC Cab & Chassis Sierra, 2009 Chevrolet Silverado, and 2009 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the automatic transmission shift lever harness connector.
- Ignition ON, verify with a scan tool the Tap Up/Down Switch parameter displays Off.
- If not the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.
- Ignition ON, test for greater than 11 V between the ignition voltage circuit terminal D and ground.
- If less than the specified value, test the ignition voltage circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.
- Ignition OFF, test for 6.6-7.0 K ohms between terminal C and terminal D of the automatic transmission shift lever harness connector. Also, test for 3.7-4.2 K ohms when selecting the minus (-) switch, and 1.7-2.0 K ohms when selecting the plus (+) switch.
- If not within the specified values, replace the automatic transmission lever.
- If the specified values are normal, test the signal circuit for a short to ground or an open/high resistance. If circuit tests normal, replace the BCM.