Haldex modal fault code reading


The system uses TODD (total on-board diagnostic display) to read out fault codes. TODD is found under the cover for the ECU.

TODD can be used to read out fault codes and also to check the ABS-sensors on the trailer.

To check the ABS-system, connect the ABS-cable between tractor and trailer, pres down the brake pedal, turn on the ignition, and check that the ABS-2 warning light in the cab and the warning light on the trailer turn on in the following order.

- Lights shall be on for 2.5 seconds.

- Lights turn off for 1 second.

- Lights turn on until a speed of 10 km/h is reached, then they shall turn off to indicate that the system is OK.

If the lights do not turn off at speeds above 10 km/h, loosen the cover for the ECU (fastened with 4 screws) and check the fault codes in TODD.

Black displayNo ignition current to ECU
00System is OK. Vehicle is moving
011A sensor/cable circuit open/break
021B sensor/cable circuit open/break
032A sensor/cable circuit open/break
042B sensor/cable circuit open/break
053A sensor/cable circuit open/break
063B sensor/cable circuit open/break
07System is OK. Vehicle stationary
08Retarder/cabling open circuit
09Retarder/cabling short-circuiting
0CReset to drive/cabling open circuit
0AReset to drive/cabling open circuit
0EWarning light circuit failure
Low sensor output groupPossible causes: worn sensor, wrong distance between sensor and sensor ring gear, open/shorted circuit.
111A sensor system failure
121B sensor system failure
132A sensor system failure
142B sensor system failure
153A sensor system failure
163B sensor system failure
20Outer ring gear
Intermittent low sensor outgoing groupLoose sensor, contact, damaged bracket for sensor, wrong distance between sensor and sensor ring gear, damaged sensor or cable.
211A sensor system failure
221B sensor system failure
232A sensor system failure
242B sensor system failure
253A sensor system failure
263B sensor system failure
37Diagnostic code sent to ABS ECU to activate light sequence
A wheel with slow reset groupBrakes return slowly, mechanical brake failure, dry bearings, wrong cabling, modulator failure.
40Sensor cabling crossed over an axle
41Slow reset of a wheel with red channel
42Slow reset of a wheel with blue channel
43Slow reset of a wheel with yellow channel
Open circuit modulator, solenoid or open circuit to solenoid group 
61Hold solenoid circuit failure, red channel
62Hold solenoid circuit failure, blue channel
63Hold solenoid circuit failure, yellow channel
67Dump solenoid circuit failure, red channel
68Dump solenoid circuit failure, blue channel
69Dump solenoid circuit failure, yellow channel
Short-circuiting modulator solenoid or solenoid circuit group 
71Hold solenoid circuit failure, red channel
72Hold solenoid circuit failure, blue channel
73Hold solenoid circuit failure, yellow channel
77Dump solenoid circuit failure, red channel
78Dump solenoid circuit failure, blue channel
79Dump solenoid circuit failure, yellow channel
Modulator solenoid circuit or solenoid short-circuiting to B+ group 
80Poor insulation in modulator solenoid or circuit failure
81Hold solenoid circuit failure red channel
82Hold solenoid circuit failure blue channel
83Hold solenoid circuit failure yellow channel
87Dump solenoid circuit failure red channel
88Dump solenoid circuit failure blue channel
89Dump solenoid circuit failure yellow channel
Power supply group 
90Power supply at ECU lower than 18v when solenoid is pulled
91Wrong power supply form ISO 7638 pin 1 or defective fuse
92Power supply at ECU higher than 32v
93Internal ECU failure
99Internal ECU failure
System function group 
A1Reset to make raising function available
A2Retarder function available
A3Axle lock signal available
Extra codes 
CAErase stored faults
CCClears configuration
CFSensor and solenoid not connected

Depending on the configuration, it is also possible to check the ABS-sensors by turning the wheels (1 rev / 2 sec) and check TODD at the same time. If the ABS-sensor is intact TODD will show this with a line in the display.

(Example 2S/1M = 2 sensors and 1 modulator.)