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5A–9

BRAKE CONTROL SYSTEM

Brake Release
At the end of the anti-lock stop, when the brake pedal is
released, the pump will remain running for a short time to
help drain any fluid from the accumulators. As this fluid
returns into the system, the spring forces the piston back
to its original position.

The isolation valve opens and fluid may return to the
master cylinder. Conventional braking is then resumed.

C05RW013

Legend

(1) Brake
(2) Master Cylinder

Summary of Contents for 1999 RODEO

Page 1: ...ccurs While ABS Works Use TECH 2 5A 31 Chart A 3 TA 3 The Wheels Are Locked 5A 32 Chart A 4 Brake Pedal Feed Is Abnormal 5A 33 Chart A 5 TA 5 Braking Sound From EHCU Is Heard While Not Braking 5A 34 D...

Page 2: ...Sensor Output Inspection Procedure 5A 54 Chart C 1 2 FR Sensor Output Inspection Procedure 5A 55 Chart C 1 3 Rear Sensor Output Inspection Procedure 5A 55 Chart TC 1 Sensor Output Inspection Procedure...

Page 3: ...adjust brake pressure to maintain best braking This system helps the driver maintain greater control of the vehicle under heavy braking conditions NOTE The Electronic Hydraulic Control Unit EHCU comp...

Page 4: ...5A 4 BRAKE CONTROL SYSTEM Functional Description Hydraulic Unit H U Solenoid Valve C05RW012 Legend 1 Isolation Valve 2 Dump valve...

Page 5: ...ck braking the solenoid valves are without current and closed due to spring force Brake fluid travels through the centre of the normally open isolation valve around the normally closed dump valve and...

Page 6: ...el deceleration imminent lockup the first step in the anti lock sequence is to isolate the brake pressure being applied by the brake pedal The microprocessor in the coil integrated module sends a volt...

Page 7: ...ith very short activation pulses opening and closing the dump valve passageway Brake pressure is reduced at the wheel and allows the wheel to begin rotating again The fluid from the brake piston is st...

Page 8: ...linder output pressure If more pressure is required more fluid is drawn from the master cylinder and applied to the brakes The driver may feel slight pedal pulsations or pedal drop this is normal and...

Page 9: ...main running for a short time to help drain any fluid from the accumulators As this fluid returns into the system the spring forces the piston back to its original position The isolation valve opens a...

Page 10: ...differential The rotor is press fit in the axle shaft The flux generated from electrodes magnetized by a magnet in the sensor varies due to rotation of the rotor and the electromagnetic induction gene...

Page 11: ...n the ignition switch to the OFF position General Service Precautions The following are general precautions which should be observed when servicing and diagnosing the Anti lock Brake System and or oth...

Page 12: ...t 7 If the abnormality is not reproduced by the test make best efforts to reproduce the situation reported by the customer 8 If the abnormality has been detected repair in accordance with the SYMPTOM...

Page 13: ...ROL SYSTEM Tech 2 Scan Tool From 98 MY Isuzu dealer service departments are recommended to use Tech 2 Please refer to Tech 2 scan tool user guide 901RW257 Legend 1 PCMCIA Card 2 SAE 16 19 Adaptor 3 DL...

Page 14: ...2 to the DLC cable 3 3 Connect the DLC cable to the Tech 2 4 4 Make sure the vehicle ignition is off 5 Connect the Tech 2 SAE 16 19 adapter to the vehicle DLC 740RW060 6 The vehicle ignition turns on...

Page 15: ...5A 15 BRAKE CONTROL SYSTEM 060RX063...

Page 16: ...Inactive Released D Active Pressed Brake Fluid Level Normal or not D To be Normal usually Return Pump Active Inactive D To be Inactive usually DRP Dynamic Rear Propor tioning Active Inactive D To be I...

Page 17: ...CAUTION D Before testing be sure that the brakes work normally D Make sure that the battery is fully charged Conduct the test by two persons A TECH 2 operator and a vehicle checker D Be sure to start...

Page 18: ...5A 18 BRAKE CONTROL SYSTEM F05RX002...

Page 19: ...5A 19 BRAKE CONTROL SYSTEM F05RX003...

Page 20: ...5A 20 BRAKE CONTROL SYSTEM F05RX004...

Page 21: ...5A 21 BRAKE CONTROL SYSTEM Tech 2 Service Bleed F05RX005...

Page 22: ...p 5 3 1 Repair of faulty part 2 Elimination of DTC 3 Inspection of ABS W L Illumination pattern with ignition SW ON 4 Test drive Does trouble repeat Repeat the diagnosis it the symptom or DTC appears...

Page 23: ...unction normal Go to Step 4 Repair Go to Step 4 4 Is the pad and rotor normal Go to Step 5 Repair Go to Step 5 5 Reconnect all components Ensure all component are properly mounted Was this step finish...

Page 24: ...4 5V Press brake pedal 4 Ground connection OFF 200W 7 C 4 Ground Less than 2W OFF 1W 2 C 5 Ground Less than 0 2W 5 FL speed sensor OFF 2kW 2 C 4 10 C 4 2 0kW to 2 8kW Internal Resistance OFF 200kW 2 C...

Page 25: ...5A 25 BRAKE CONTROL SYSTEM Circuit Diagram D08RX108...

Page 26: ...5A 26 BRAKE CONTROL SYSTEM D08RX110...

Page 27: ...5A 27 BRAKE CONTROL SYSTEM D08RX109...

Page 28: ...5A 28 BRAKE CONTROL SYSTEM Connector List No Connector face No Connector face B 19 H 13 H 14 C 4 H 26 C 5 I 1 C 13 C 33 I 18 C 16 C 36 E 28 E 30 C 34 F 4 H 5 H 12 H 15 H 25...

Page 29: ...M Part Location D08RX107 Legend 1 Battery 2 Fuse Relay Box 3 C 36 4 C 5 5 C 4 6 H 12 13 14 7 I 18 8 Starter Switch 9 I 1 10 C 34 11 F 4 12 H 26 13 H 25 14 H 15 15 C 16 16 C 13 17 H 5 18 B 19 19 E 30 6...

Page 30: ...rake pedal feel is abnormal Chart A 4 5 Braking sound from EHCU is heard while not braking Chart A 5 Chart TA 5 Chart A 1 ABS Works Frequently But Vehicle Does Not Decelerate Step Action Yes No 1 Is b...

Page 31: ...sensor normal Refer to chart C 1 or TC 1 Go to Step 4 Replace sensor or repair harness Go to Step 5 4 Is brake pipe connecting order correct Replace H U Go to Step 5 Reconnect brake pipe correctly Go...

Page 32: ...l Chart C 1 or TC 1 Go to Step 4 Replace sensor or repair harness Go to Step 6 4 Is front 4WD controller normal Go to Step 5 Replace 4WD controller or repair harness Go to Step 6 5 Is hydraulic unit g...

Page 33: ...battery voltage Go to Step 4 Harness NG between brake SW and EHCU Go to Step 6 3 Is stop light fuse normal Go to Step 5 Replace stop light fuse Go to Step 6 4 Is the check continuity between EHCU con...

Page 34: ...rical equipment switches D At the time of racing the engine over 5000 rpm Did it occur under any one condition above ABS may sometime be actuated even when brake pedal is not applied Go to Step 4 4 Is...

Page 35: ...l 4WD only Wiring B 8 32 C0267 Open motor circuit or shorted ECU output Motor B 9 C0268 Stalled motor or open ECU output Motor B 9 35 C0265 Open relay circuit Relay B 10 C0266 Shorted relay circuit Re...

Page 36: ...sensor B 19 61 C0226 FL Missing sensor signal B 20 C0227 FL Sensor signal dropout Sensor or B 20 62 C0222 FR Missing sensor signal Wiring B 21 C0223 FR Sensor signal dropout B 21 63 C0236 Rear Missin...

Page 37: ...ng circuit trouble Go to Chart B 1 3 Warning light remains ON Diagnostic trouble codes are stored Display diagnostic trouble codes and diagnose on a code basis according to the flow charts 4 Warning l...

Page 38: ...IGN ON The DLC is located behind the driver side kick panel 350RW016 D Keep 12 terminal connected with 4 terminal or 5 terminal GND during DTC display If 12 terminal is separated from 4 terminal or 5...

Page 39: ...the brake pedal is depressed D Up to 3 different codes can be stored D If the ABS should turn OFF due to an intermittent defect the system will be restored at the next key cycle if the initial check...

Page 40: ...2 Disconnect coil integrated module connector C 4 3 Turn the key ON Is the check voltage between coil integrated module connector C 4 terminals 6 and 7 than battery voltage Go to Step 4 Repair harness...

Page 41: ...tion Voltage DTC 15 Flash out C0277 0278 Serial communications Step Action Yes No 1 Is the check battery voltage normal Battery capacity check Go to Step 2 Charge or replace battery Go to Step 2 2 1 T...

Page 42: ...1 Serial communications Step Action Yes No 1 Is the stop light actuated when the brake pedal is depressed Go to Step 2 Go to Step 4 2 1 Turn the key off 2 Disconnected coil integrated module connector...

Page 43: ...tions Step Action Yes No 1 1 Turn the key off 2 Disconnect coil integrated module connector 3 Measure the voltage between terminal 1 of the coil integrated module connector C 5 and body ground Is the...

Page 44: ...key switch to off 2 Disconnect the 2 way EHCU connector C 5 from the EHCU 3 Inspect the connector for damage or corrosion Is the connector free from damage or corrosion Go to Step 3 Repair the connec...

Page 45: ...1 Turn the key switch to off 2 Disconnect the 2 way EHCU connector C 5 from the EHCU 3 Inspect the connector for damage or corrosion Is the connector free from damage or corrosion Go to Step 3 Repair...

Page 46: ...Speed Sensor Open or Shorted DTC 51 Flash out C0225 Serial communications Step Action Yes No 1 1 Turn the key off 2 Disconnect coil integrated module connector 3 Measure the resistance between coil in...

Page 47: ...ween speed sensor and coil integrated module Fault found Repair and perform system self check No fault found Replace coil integrated module Go to Step 3 Go to Step 2 2 Measure the FR speed sensor resi...

Page 48: ...rness between speed sensor and coil integrated module Fault found Repair and perform system self check No fault found Replace EHCU Go to Step 3 Go to Step 2 2 Measure the Rear speed sensor resistance...

Page 49: ...grated module Go to Step 6 Replace sensor Go to Step 6 4 Damage and powered iron sticking to sensor sensor ring Repair Go to Step 6 Go to Step 5 5 Is sensor output normal Chart C 1 1 or TC 1 Check for...

Page 50: ...grated module Go to Step 6 Replace sensor Go to Step 6 4 Damage and powered iron sticking to sensor sensor ring Repair Go to Step 6 Go to Step 5 5 Is sensor output normal Chart C 1 2 or TC 1 Check for...

Page 51: ...ntegrated module Go to Step 6 Replace sensor Go to Step 6 4 Damage and powered iron sticking to sensor sensor ring Repair Go to Step 6 Go to Step 5 5 Is sensor output normal Chart C 1 3 or TC 1 Check...

Page 52: ...sor resistance at the sensor connector Is the resistance between 2 0k and 2 8k ohms Repair harness abnormality between sensors and coil integrated module Go to Step 5 Replace sensor Go to Step 5 5 Dam...

Page 53: ...or repair Go to Step 8 Go to Step 7 7 Is the check wiring between sensor and coil integrated module normal Replace EHCU Go to Step 8 Repair and perform system self check Go to Step 8 8 1 Reconnect al...

Page 54: ...while turning FL wheel at a speed of 1 RPS Is the check between coil integrated module connector C 4 terminals 2 and 10 than under 200 mV Go to Step 2 OK Go to Step 3 2 1 Disconnect the wheel speed s...

Page 55: ...all components are properly mounted Was this step finished Repeat the Basic diagnostic flow chart Go to Step 3 Chart C 1 3 Rear Sensor Output Inspection Procedure Step Action Yes No 1 1 Turn the key...

Page 56: ...r Go to Step 3 3 Check the wheel speed of each sensor by Data List Is the vehicle speed normal Go to Step 6 Go to Step 4 4 Check the sensor rotor Is the sensor rotor normal Replace speed sensor Go to...

Page 57: ...KE CONTROL SYSTEM Special Tools ILLUSTRATION TOOL NO TOOL NAME J 35616 Connector test adapter kit J 39200 High impedance multimeter 7000086 ISU Tech 2 Set 1 PCMCIA Card 2 SAE 16 19 Adapter 3 DLC Cable...

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