P0789 Shift Timing Solenoid A Intermittent

Common causes

• Most likelyLoose connector at the transmission
• Less likelyConnector with intermittent contact under vibration
• Less likelyHarness routed against vibrating component

Symptoms

• Check engine or transmission warning light on
• Harsh, delayed, or missing shifts
• Possible limp mode (locked in one gear)
• Slipping or shuddering during gear changes

Repair at a glance

Difficulty

Medium

DIY friendly

Best left to a mechanic

Typical labour

0.8–3 h

Emissions test

Usually unaffected

Parts involved

Shift Timing Solenoid A, Tcm

Related codes

• P0785Shift Timing Solenoid A
• P078EShift Timing Solenoid B Intermittent
• P0786Shift Timing Solenoid A Range/Performance
• P0787Shift Timing Solenoid A Low
• P0788Shift Timing Solenoid A High
• P078AShift Timing Solenoid B
• P078BShift Timing Solenoid B Range/Performance
• P078CShift Timing Solenoid B Low