John Deere 000738.05 – PTQ: Gear Selector Range Solenoid A-B Amps Low Main Control Module

The fault code indicates that the current draw for the Gear Selector Range Solenoid A-B (responsible for changing gear range H1) is below the expected level in the Main Control Module. This low current condition suggests a problem with the electrical circuit supplying power to the solenoid or the solenoid coil itself, such as an open circuit, a high-resistance connection, or a faulty solenoid, which may affect the proper operation of the gear selection system.

• 6M
• 6R
• 6020
• 7020

1. 1

   Cycle the ignition key off and on to verify if the code is still active or was triggered by a transient condition.

2. 2

   Check the transmission oil level to ensure baseline transmission health.

3. 3

   Inspect the battery and charging system for low system voltage, damage, or corrosion.

4. 4

   Visually inspect the wiring harness leading from the PTQ control unit to the transmission case and the specific range solenoid for chafing, corrosion, or loose connectors.

5. 5

   Disconnect the electrical connectors at the suspect solenoid and the PTQ controller to check for corroded, bent, or pushed-out pins, and look for oil seeping through the solenoid connector into the wiring.

6. 6

   Perform a solenoid activation test by listening for an audible 'click' from the solenoid when the transmission is commanded to shift into the A-B range.

7. 7

   Test for voltage at the solenoid's electrical connector using a multimeter with the ignition on and the transmission commanded to the relevant range.

8. 8

   Measure the resistance across the disconnected solenoid terminals using a multimeter (typical resistance is 40 ± 5 ohms; significantly higher indicates an open circuit, lower indicates a short).

1. 1

   Isolate the faulty component

   Based on the diagnostic checks, determine if the fault lies with the wiring, the connector, or the solenoid itself.

2. 2

   Repair wiring harness

   If the wiring is found to be damaged, repair or replace the affected section of the harness. Ensure all connections are clean and secure.

3. 3

   Replace the solenoid

   If the solenoid is determined to be faulty, drain the transmission oil, remove the old solenoid from the transmission housing, and install the new one. Replace any associated seals or O-rings at the same time.

4. 4

   Perform final system checks

   Refill the transmission with the correct type and amount of hydraulic oil. Start the tractor and operate the transmission through all ranges to ensure the fault code does not return and shifting is smooth. Perform a transmission calibration if necessary.