Checking the ABS anti-lock braking system components (VW Lt 2d)

Checking the components of the ABS anti-lock braking system version 5.0 is given in Table 8.4, and the ABS anti-lock braking system version 5.3 is given in Table 8.5.

Table 8.4. Checking the components of the ABS anti-lock braking system version 5.0

Steps	VAG 1598 tester sockets	The unit being tested	Test state	Specified value
1	2 + 1	Supply voltage of the ABS return pump to the control unit	The ignition is off	10.0-14.5 V
2	3 + 1	Supply voltage of the valves in the hydraulic block to the control unit
3	4 +1	Supply voltage to the control unit	The ignition is on
4	28 + 1	Brake light switch	Ignition is on, pedal is not pressed	0.0-0.5 V
			The pedal is pressed	Battery voltage
5	1 + 15	Ground connection of the control unit	The ignition is off	Max 1.5 Ohm
6	23 + 24	Front right wheel speed sensor resistance	The ignition is off	Wabko 1.1-1.3 kOhm
				Bosch 1.6-1.9 kOhm
7	16 + 17	Front left wheel speed sensor resistance	The ignition is off	Wabko 1.1-1.3 kOhm
				Bosch 1.6-1.9 kOhm
8	20 + 21	Rear right wheel speed sensor resistance	The ignition is off	Wabko 1.1-1.3 kOhm
				Bosch 1.6-1.9 kOhm
9	18 + 19	Rear left wheel speed sensor resistance	The ignition is off	Wabko 1.1 -1.3 kOhm
				Bosch 1.6-1.9 kOhm
10	23 + 24	Voltage at the front right wheel speed sensor	The car is raised, the ignition is off. Rotate the wheel approximately 1 revolution/second	At least 65 mV
11	16 + 17	Voltage at the front left wheel speed sensor
12	20 + 21	Voltage at the rear right wheel speed sensor
13	18 + 19	Voltage at the rear left wheel speed sensor
14	—	Supply voltage for the VAG 1551 tester, T14 connector	Ignition off, connect the VAG 1526 multimeter between the wiring connectors T14/1 and T14/3	10.0-14.5 V
15	—	K-wire resistance for VAG 1551 tester, T14 connector	With the ignition off, disconnect the connector from the ABS control unit. Connect the VAG 1598/21 tester. Connect the VAG 1526 multimeter between contacts T14/13 and T40/29 of the ABS control unit connector	Max 1.5 Ohm
16	—	ABD/EDL indicator light operation	The ignition is off. Turn on the ignition	The ABD/EDL indicator light comes on for approximately 2 seconds and goes out
17	—	ABS warning light operation		The ABS warning light comes on for about 2 seconds and goes out
18	—	Operation of the brake warning light	The ignition is off, the brake fluid level is normal, the brake pads are not worn. Turn on the ignition	The brake system warning light comes on
			Start the engine	The brake system warning light goes out

Table 8.5. Checking the components of the ABS anti-lock braking system version 5.3

Steps	VAG 1598 tester sockets	The unit being tested	Test state	Specified value
1	17 + 19	Supply voltage to the control unit	The ignition is on	10.0-14.5 V
2	18 + 16
3	19 + 15
4	4 + 5	Front right wheel speed sensor resistance	The ignition is off	Wabko 1.1-1.3 kOhm Bosch 1.6-1.9 kOhm
5	6 + 7	Front left wheel speed sensor resistance
6	1 + 2	Rear right wheel speed sensor resistance
7	8 + 9	Rear left wheel speed sensor resistance
8	4 + 5	Voltage at the front right wheel speed sensor	The car is raised, the ignition is off. Rotate the wheel approximately 1 revolution/second	At least 65 mV
9	6 + 7	Voltage at the front left wheel speed sensor
10	1 + 2	Voltage at the rear right wheel speed sensor
11	8 + 9	Voltage at the rear left wheel speed sensor
12	—	Supply voltage for the VAG 1551 tester, T14 connector	Ignition off, connect the VAG 1526 multimeter between the wiring connectors T14/1 and T14/3	10.0-14.5 V
13	—	K-wire resistance for VAG 1551 tester, T14 connector	With the ignition off, disconnect the connector from the ABS control unit. Connect the VAG 1598/21 tester. Connect the VAG 1526 multimeter between contacts T14/1& and T31/11 of the ABS control unit connector	Max 1.5 Ohm
14	—	ABD/EDL indicator light operation	The ignition is off. Turn on the ignition	The ABD/EDL indicator light comes on for approximately 4 seconds and goes out
15	—	ABS warning light operation		The ABS warning light comes on for about 4 seconds and goes out
16	—	Operation of the brake warning light	The ignition is off, the brake fluid level is normal, the brake pads are not worn. Turn on the ignition	The brake system warning light comes on
			Start the engine	The brake system warning light goes out
17	14 + 16	Operation of the brake light switch	Ignition is on, pedal is not pressed	0.0-0.5 V
			The pedal is pressed	Battery voltage