Powertrain, generic · Transmission

P08D2 Shift Solenoid J Control Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

Set when the TCM sees too little voltage on the control line of shift solenoid J, typically because the line or the coil is shorted to ground. No manufacturer documents this code publicly; J would be a tenth on/off valve, which none of the known transmission sources assigns. GM's analogue for solenoid A, P0973 on the 6-speed units, fails when the output driver reports a ground short for 1.2 of 1.5 seconds and lights the MIL after one trip; Ford names the same fault on its solenoids a short to ground. CARB requires such circuit checks. P08D3 is the high-side fault, P08D4 the open circuit. The TCM usually switches the valve off and runs a substitute gear.

Likely causes

Control wire chafed through and shorted to ground

Solenoid coil with internal short

Damaged internal transmission harness or lead frame

Faulty output stage in the TCM

Symptoms

Check engine or transmission warning light on
Transmission holds a substitute gear
Harsh or missing shifts

Repair estimate

DifficultyHardWorkshop job

Parts and labour€100–1,500

Time1–5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift solenoid jwiring harness

References: gsi.ext.gm.com, fordservicecontent.com, law.cornell.edu.