ZF AS-Tronic fault codes
Updated: 2026-11-10
The reference covers 166 ZF AS-Tronic codes from factory tables — the code and what it means. ZF AS-Tronic numbers faults its own way, not by J1939 SPN.
ZF AS-Tronic codes: what to know
ZF AS-Tronic has its own numbering: the number in the table is an internal ZF code, not an SPN. There are 166 codes. The numbers name specific parts: 2 is valve Y2, 3 is valve Y3, 4 to 7 are the selector valves, and 10 is the main air valve Y10. So read the description on this page, not the title of the code page with the same number.
All ZF AS-Tronic codes — 166
- 2.5Short circuit to ground on valve Y2 output (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 3.5Short circuit to ground on valve Y3 output (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 4.5Short circuit to ground on valve Y4 output (range selector valve).
- 5.5Short circuit to ground on valve Y5 output (range selector valve).
- 6.5Short circuit to ground on valve Y6 output (range selector valve).
- 7.5Short circuit to ground on valve Y7 output (range selector valve).
- 8.5Short circuit to ground on valve Y8 output (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 9.5Short circuit to ground on valve Y9 output (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 9.9Communication fault between processor 1 (P1) and processor 2 (P2) — internal TCU electronics failure.
- 10.5Short circuit to ground on main air valve Y10 output. No air pressure at the engagement valves.
- 12.0Short circuit to ground on the ZF controller output connected to the reverse light relay.
- 13.0Short circuit to ground on the ZF E-module output connected to power take-off 1 (PTO1).
- 14.0Short circuit to ground on the ZF E-module output connected to power take-off 2 (PTO2).
- 17.5Short circuit to ground on transmission brake valve Y1 output.
- 18.5Short circuit to ground on valve Y17 output (clutch slow release).
- 19.5Short circuit to ground on valve Y15 output (clutch slow engagement).
- 20.5Short circuit to ground on valve Y16 output (clutch fast release).
- 21.5Short circuit to ground on valve Y14 output (clutch fast engagement).
- 22.5Short circuit to ground on ADVP/ADVP1 output (power supply for output shaft 1 speed sensor).
- 26.4CAN message timeout: "engine brake configuration" (engine configuration message).
- 27.8No CAN bus signal: "engine brake configuration" (engine configuration message).
- 28.8No CAN bus signal: "driveline retarder — actual percent torque".
- 29.8No CAN bus signal: "engine requested cooling fan increase".
- 30.8No CAN bus signal: "secondary retarder configuration".
- 31.8No CAN bus signal: "engine retarder — actual percent torque".
- 32.8No CAN bus signal: "engine brake configuration".
- 33.4CAN message timeout: "engine brake configuration".
- 34.10Fault on valve Y2 output circuit (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 35.10Fault on valve Y3 output circuit (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 36.10Fault on valve Y4 output circuit (range selector valve).
- 37.10Fault on valve Y5 output circuit (range selector valve).
- 38.10Fault on valve Y6 output circuit (engagement valve).
- 39.10Fault on valve Y7 output circuit (engagement valve).
- 40.10Fault on valve Y8 output circuit (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 41.10Fault on valve Y9 output circuit (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 42.10Loss of output signal to main air valve Y10. No air supply.
- 45.0Fault on the ZF E-module output to the power take-off 1 (PTO1) valve.
- 46.0Fault on the ZF E-module output to the power take-off 2 (PTO2) valve.
- 49.10Fault on transmission brake valve Y1 output circuit.
- 50.10Fault on valve Y17 output circuit (clutch slow release).
- 51.10Fault on valve Y15 output circuit (clutch slow engagement).
- 52.10Fault on valve Y16 output circuit (clutch fast release).
- 53.10Fault on valve Y14 output circuit (clutch fast engagement).
- 54.10Fault on ADVP/ADVP1 output (power supply for output shaft 1 speed sensor).
- 59.8Fault in the power take-off 1 (PTO1) engagement confirmation signal.
- 60.8Fault in the power take-off 2 (PTO2) engagement confirmation signal.
- 61.8Fault while disengaging power take-off 1 (PTO1).
- 62.8Fault while disengaging power take-off 2 (PTO2).
- 63.8Fault while engaging power take-off 1 (PTO1).
- 64.8Fault while engaging power take-off 2 (PTO2).
- 65.1Transmission oil temperature too high.
- 66.6Short circuit to positive supply on valve Y2 output (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 67.6Short circuit to positive supply on valve Y3 output (front splitter group). With a direct-drive (DD) gearbox, shifting into the fast group is not possible. With an overdrive (OD) gearbox, shifting into the slow group is not possible.
- 68.6Short circuit to positive supply on valve Y4 output (range selector valve).
- 69.6Short circuit to positive supply on valve Y5 output (range selector valve).
- 70.6Short circuit to positive supply on valve Y6 output (engagement valve).
- 71.6Short circuit to positive supply on valve Y7 output (engagement valve).
- 72.6Short circuit to positive supply on valve Y8 output (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 73.6Short circuit to positive supply on valve Y9 output (rear splitter group). For AS Tronic 2: engaging the slow group is not possible. For AS Tronic mid: engaging the fast group is not possible.
- 74.6Short circuit to positive supply on main air valve Y10 output.
- 76.0Short circuit to positive supply on the ZF controller output connected to the reverse light relay.
- 77.0Short circuit to positive supply on the ZF E-module output connected to power take-off 1 (PTO1).
- 78.0Short circuit to positive supply on the ZF E-module output connected to power take-off 2 (PTO2).
- 81.6Short circuit to positive supply on transmission brake valve Y1 output.
- 82.6Short circuit to positive supply on valve Y17 output (clutch slow release).
- 83.6Short circuit to positive supply on valve Y15 output (clutch slow engagement).
- 84.6Short circuit to positive supply on valve Y16 output (clutch fast release).
- 85.6Short circuit to positive supply on valve Y14 output (clutch fast engagement).
- 86.6Short circuit to positive supply on ADVP/ADVP1 output (power supply for output shaft 1 speed sensor).
- 91.4CAN bus request timeout: EBC1 (brake request message).
- 92.8No CAN bus signal: "ABS control active".
- 93.8No CAN bus signal: "ASR engine control active" (EBC1 message).
- 94.8No CAN bus signal: "ASR brake control active" (EBC1 message).
- 95.8No CAN bus signal: "cruise control active".
- 96.8No CAN bus signal: "cruise control set speed".
- 97.8No CAN bus signal: "engine speed".
- 98.8No signal from the ZF "transmission input shaft speed" sensor.
- 99.8No signal from the ZF "output shaft 1 speed" sensor.
- 100.8No signal from the ZF "output shaft 2 speed" sensor.
- 101.3Input-to-output shaft speed ratio out of tolerance.
- 101.8No signal from the ZF "output shaft speed" sensor and no CAN bus "output shaft speed" signal.
- 103.0No CAN bus signal: "vehicle speed".
- 104.1Vehicle on-board electrical system voltage too high.
- 105.2Vehicle on-board electrical system voltage too low.
- 107.2Clutch sensor supply voltage out of range (output AU).
- 108.8Mechanical fault in the rotary switch.
- 110.0ZF-CAN bus timeout.
- 113.4CAN bus timeout: "retarder configuration".
- 114.0Clutch closes unintentionally, whether in neutral or while driving.
- 115.0Shift lever fault.
- 117.0Fault detecting clutch status.
- 118.0Clutch does not disengage.
- 119.0Clutch not engaged, no engine torque.
- 120.0Mechanical fault in valve Y17.
- 121.0Mechanical fault in valve Y16.
- 122.0Mechanical fault in valve Y15.
- 123.0Mechanical fault in valve Y14.
- 124.0No "clutch travel" signal.
- 125.0Pressure-reducing valve failure.
- 126.3No signal from the pressure sensor.
- 127.3No signal from the transmission temperature sensor.
- 128.3No signal from the oil temperature sensor.
- 129.6Short circuit to positive supply on the shift sensor (main gearset).
- 130.5Short circuit to ground on the shift sensor (main gearset).
- 131.10No signal from the shift sensor (main gearset).
- 132.9Self-test fault on the shift sensor (main gearset).
- 133.6Short circuit to positive supply on the electronic accelerator pedal sensor.
- 134.5Short circuit to ground on the electronic accelerator pedal sensor.
- 135.10No signal from the electronic accelerator pedal sensor.
- 136.9Self-test fault on the electronic accelerator pedal sensor.
- 137.6Short circuit to positive supply on the rear splitter sensor.
- 138.5Short circuit to ground on the rear splitter sensor.
- 139.10No signal from the rear splitter sensor.
- 140.9Self-test fault on the rear splitter sensor.
- 141.6Short circuit to positive supply on the front splitter sensor.
- 142.5Short circuit to ground on the front splitter sensor.
- 143.10No signal from the front splitter sensor.
- 144.9Self-test fault on the front splitter sensor.
- 145.0Rear splitter group fails to disengage.
- 146.0No shift confirmation when engaging the rear splitter group.
- 147.0Rear splitter group fails to engage.
- 148.0Front splitter group fails to disengage.
- 149.0No shift confirmation when engaging the front splitter group.
- 150.0Front splitter group fails to engage.
- 151.0Range-select cylinder fails to disengage.
- 152.0No shift confirmation on the range-select cylinder.
- 153.0Range-select cylinder fails to engage.
- 154.0Main gear fails to disengage.
- 155.0Main gear fails to engage.
- 156.0Incorrect shift in the main gearset.
- 157.0Main gear engagement sensor signal stays in the selected position.
- 158.0Main gear engagement sensor signal stays in the position selected by the driver.
- 159.0Rear splitter engagement sensor signal does not hold the selected position while driving.
- 160.0Front splitter engagement sensor signal does not hold the selected position while driving.
- 163.0No signal from the engine speed sensor.
- 164.8No CAN bus signal: "engine torque from electronic accelerator pedal position".
- 165.8No CAN bus signal: "electronic accelerator pedal position".
- 166.0The electronic accelerator pedal is in the idle position.
- 168.8No idle signal from the electronic accelerator pedal.
- 169.0No signal from the transmission control unit about the main relay switching off.
- 170.0No supply voltage on the main relay (terminal 30).
- 171.8No CAN bus signal: "engine torque".
- 173.8No signal from the brake sensor.
- 174.8No signal from the kickdown switch.
- 175.4No supply voltage on "ignition" (terminal 15).
- 177.4CAN bus inactive.
- 178.4CAN bus fault.
- 179.0CAN bus message timeout exceeded.
- 180.4CAN message timeout: "EEC1".
- 181.4CAN message timeout: "EEC2".
- 182.4CAN message timeout: "CCVS".
- 183.4CAN message timeout: "ERC1_ER" (engine brake).
- 184.4CAN message timeout: "ERC1_DR" (retarder).
- 188.0Fault in the main control unit, or the control unit and software are incompatible.
- 189.0Main control unit program failure.
- 190.0EEPROM programming parameter out of range.
- 191.0EEPROM programming parameter checksum error.
- 192.0EEPROM error in the main control unit, or checksum error (processor 2).
- 193.1Transmission control unit temperature too high.
- 194.0Both front-axle speed signal sources are missing.
- 197.8No CAN bus signal: "front axle speed".
- 199.4CAN bus timeout: "wheel speed reading".
- 227.0CAN parameter configuration error in the data field.
- 231.4CAN bus timeout: "EEC3".
- 250.0Internal controller fault.
- 251.0Internal expansion module (E-module) fault.
How to read the number
ZF AS-Tronic numbers its faults its own way, not by the J1939 SPN standard: the first part is the fault number, after the dot — its type. The same number on an engine or another make means something else.
Know the code number? Type it into the search — or paste the whole list from the scanner and we will show which fault is the real one.