P2779
P2779-AUTOSTICK DOWNSHIFT SWITCH CIRCUIT PERFORMANCE - ESMTheory of Operation
The AutoStick Switch is integrated into the Shift Lever Assembly. The gear requested by the AutoStick selection is then sent over the CAN C bus from the Electronic Shift Module (ESM) to the TCM to engage the requested gear.
- When Monitored:
When in AutoStick mode.
- Set Condition:
When the expected switch state is not correctly sensed by the Shifter Lever Assembly (SLA) Electronic Shift Module (ESM). If the upshift switch signal is detected as active in gear position other than drive or both upshift and downshift signals are active at the same time.
Possible Causes
SHIFTER LEVER ASSEMBLY
Diagnostic Test
1. SHIFT LEVER ASSEMBLY
View repair
Repair
Using the schematics as a guide, check the Shifter Lever Assembly (SLA) Electronic Shift Module (ESM) terminals for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the Shifter Lever Assembly.
Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1. Verification Tests