Engine Control Unit (ECU) Service Codes

Symptom Problem Solution

CODE ECU 19

Engine coolant temperature data not valid or not received

Have your John Deere Dealer repair as soon as possible

ECU's high coolant temperature engine protection feature disabled

Have your John Deere Dealer repair as soon as possible

CODE ECU 21, 22

Sensor supply voltage out of range

Have your John Deere Dealer repair as soon as possible

CODE ECU 26

Manifold air temperature data not valid or not received

Have your John Deere Dealer repair as soon as possible

CODE ECU 27

Throttle position data not valid or not received

Have your John Deere Dealer repair as soon as possible

Engine will only idle

Have your John Deere Dealer repair as soon as possible

CODE ECU 28

Engine Control Unit (ECU) error

Have your John Deere Dealer repair as soon as possible

CODE ECU 31, 34, 53

Fuel injection pump rack position error

Have your John Deere Dealer repair as soon as possible

Engine does not start, runs erratically, or possible power changes

Have your John Deere Dealer repair as soon as possible

CODE ECU 35, 36

Fuel injection pump rack position voltage out of range

Have your John Deere Dealer repair as soon as possible

Engine does not start, runs erratically, or possible power changes

Have your John Deere Dealer repair as soon as possible

CODE ECU 37, 38

Fuel temperature voltage out of range (sensor) - No harm to engine

Have your John Deere Dealer repair at earliest convenience

Engine power changes, hard or smoky starting - No harm to engine

Have your John Deere Dealer repair at earliest convenience

AG,RX15494,2908 -19-07FEB00-1/3


Symptom Problem Solution

CODE ECU 41

Start signal missing

Have your John Deere Dealer repair at earliest convenience, if not caused by key switch operation

Key switch turned to OFF and back ON while engine was running

Wait for engine to come to complete stop before restarting

CODE ECU 42

Engine overspeed

Result of downshifting, throttle back

Have your John Deere Dealer repair as soon as possible

CODE ECU 44

Erratic engine speed input

Have your John Deere Dealer repair as soon as possible

CODE ECU 46

Start signal always active

Have your John Deere Dealer repair as soon as possible

CODE ECU 48

Fuel shut-off circuit fault

Have your John Deere Dealer repair as soon as possible

Engine will not start

Have your John Deere Dealer repair as soon as possible

CODE ECU 54

Intermittent loss of Engine Control Unit (ECU) power supply

Have your John Deere Dealer repair at earliest convenience

CODE ECU 55

Controller Area Network (CAN) error

Have your John Deere Dealer repair as soon as possible

CODE ECU 61

Loss of coolant detected - Engine damage possible

Stop engine, have your John Deere Dealer repair immediately

CODE ECU 62

Engine coolant temperature moderately high

Check for debris restricting radiator air flow, reduce load on engine, have your John Deere Dealer repair as soon as possible

CODE ECU 63

Engine coolant temperature extremely high - Engine damage possible

Stop engine, have your John Deere Dealer repair immediately

CODE ECU 66

Manifold air temperature high

Check for debris restricting aftercooler air flow, reduce load on engine, have your John Deere Dealer repair as soon as possible

AG,RX15494,2908 -19-07FEB00-2/3


Symptom Problem Solution

CODE ECU 67

Engine protection shutdown notification

Stop engine, have your John Deere Dealer repair immediately

CODE ECU 68

Engine protection derate notification

Have your John Deere Dealer repair as soon as possible

CODE ECU 75, 76, 77

Fuel injection pump rack actuator fault

Have your John Deere Dealer repair as soon as possible

Engine does not start, runs erratically, or possible power changes

Have your John Deere Dealer repair as soon as possible

CODE ECU 81

Fuel level low

Fill tank with fuel

Fuel temperature high

Have your John Deere Dealer repair as soon as possible

CODE ECU 83

External engine shutdown request received

Have your John Deere Dealer repair as soon as possible

Engine dies and will not restart

Have your John Deere Dealer repair as soon as possible

CODE ECU 85, 86, 87

Engine speed sensor fault

Have your John Deere Dealer repair as soon as possible

Engine does not start or runs erratically

Have your John Deere Dealer repair as soon as possible

AG,RX15494,2908 -19-07FEB00-3/3