B2300 Regular Cab 2WD L4-2.3L VIN A (1997)
1. Disconnect the hydraulic unit connector.
2. Measure the resistance between terminals 4 and 3 at the hydraulic unit.
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Resistance: approx. 1-3 ohms.
3. If not as specified, replace the hydraulic unit.
Check Hydraulic Unit Internal Circuit
1. Disconnect the hydraulic unit connector.
2. Measure the resistance between terminals 2 and 3 at the hydraulic unit.
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Resistance: approx. 18-26 Kohms.
3. If not as specified, replace the hydraulic unit.
Test 1
1. Disconnect the hydraulic unit connector.
2. Measure the resistance between terminal 2 and the hydraulic unit body.
3. Depress the brake pedal and apply hydraulic pressure for at least 30 seconds.
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Resistance: greater than 10 Kohms.
4. If not as specified, replace the hydraulic unit.
Test 2
1. Drive the vehicle at approximately 16 km/h (10 mph) on dry pavement.
2. Depress the brake pedal hard enough to lock all wheels.
3. After the vehicle has stopped, place the vehicle in Park (AT) or Neutral (MT) and take foot off of the brake pedal and wait 30 seconds.
4. If the rear ABS warning light illuminates, perform the self-diagnosis function.
Check Hydraulic Unit For Leakage
1. Press hard on the brake pedal with the engine running and keep pressure for 30 seconds.
2. Monitor the height of the brake pedal while keeping pressure on it.
