Interpreting XR25 bar graphs
WARNINGS None.
| Make sure the XR25 tool is not the cause of the fault by trying to communicate with an ECU on another vehicle. If the XR25 tool is not at fault and communication cannot be established with any other ECU on the same vehicle, a faulty ECU may be disrupting the K and L diagnostic lines. Carry out successive disconnections to locate this ECU. Check that the ISO interface is set to position S8, that you are using the latest XR25 cartridge version, and that the correct access code is entered. Check the battery voltage and carry out the necessary work to obtain a compliant voltage (9.4 volts < U battery < 17.4 volts). |
| Check the presence and condition of the ABS fuse in the passenger compartment interconnection box (10A). Check the ECU connector connection and the condition of its terminals. Check the connection and condition of the wiring at the R36 dashboard / ABS connector. Check the ABS earths (tightness of the two earth screws above the ABS unit). Check that the ECU is correctly supplied:
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Check that the diagnostic socket is correctly supplied:
Check the continuity and insulation of the lines between the diagnostic socket and the ABS ECU:
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| If communication still cannot be established after these checks, replace the ABS ECU. |
AFTER REPAIR Once communication is established, clear any fault bar graphs that are on.
WARNINGS None.
| Check the condition and position of the 60A ABS fuse in the engine interconnection box (white bracket). Check continuity between this fuse and pins 17 and 18 of the ECU connector (+ AVC present on both pins). Check the tightness and condition of the battery terminals. Check the connector on the 31-pin ABS ECU connector. Check the ABS earths (above the hydraulic unit) and visually inspect all of the ABS wiring. |
| Erase the ECU memory, exit diagnostic mode (G13*) and switch the ignition off. Carry out a new XR25 check. If the "power supply / ECU" fault persists, replace the ABS ECU. |
AFTER REPAIR After replacing the ECU, carry out a new check with the XR25 tool.
NOTES Even if present at the time of the check, these faults will always be reported by a flashing bar graph.
To confirm their presence and therefore the need to apply the diagnosis below, run command G20*. The fault is present if the bar graph comes back on steady at the end of the command.
If bar graph 11 left is also on, address bar graph 11 left first.
| Check the ABS earths (tightness of the two screws above the hydraulic unit). Check the condition and position of the 60A ABS fuse in the engine interconnection box (white bracket). Check the connection and condition of the connector on the 31-pin ECU connector. |
| Erase the ECU memory, exit diagnostic mode (G13*) and switch the ignition off. Switch the ignition on and carry out a new check with the XR25 tool using command G20*. If the "solenoid valve circuit" fault reappears, replace the ABS ECU. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
WARNINGS None.
| Check the connection and condition of the sensor connector. If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
If the resistance is correct, check and confirm the continuity of the wiring between the sensor connector and the ECU connector:
Also check the insulation between these wires. Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If all checks are correct, reconnect the ECU and the wheel speed sensor, then erase the ECU memory. Exit diagnostic mode (G13*) and switch the ignition off. Switch the ignition back on and replace the sensor if the fault reappears. If the fault reappears after replacing the sensor, replace the ECU. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
WARNINGS None.
| Check the connection and condition of the sensor connector. If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
If the resistance is correct, check and confirm the continuity of the wiring between the sensor connector and the ECU connector:
Also check the insulation between these wires. Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If all checks are correct, reconnect the ECU and the wheel speed sensor, then erase the ECU memory. Exit diagnostic mode (G13*) and switch the ignition off. Switch the ignition back on and replace the sensor if the fault reappears. If the fault reappears after replacing the sensor, replace the ECU. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
WARNINGS None.
| Check the connection and condition of the sensor connector. Check the connection at the underbody intermediate connector (R101). If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
If the resistance is correct, check and confirm the continuity of the wiring between the sensor connector and the ECU connector:
Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If all checks are correct, reconnect the ECU and the wheel speed sensor, then erase the ECU memory. Exit diagnostic mode (G13*) and switch the ignition off. Switch the ignition back on and replace the sensor if the fault reappears. If the fault reappears after replacing the sensor, replace the ECU. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
INSTRUCTIONS None
| Check the connection and condition of the sensor connector. Check the connection at the underbody intermediate connector (R101). If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
If the resistance is correct, check and confirm the continuity of the wiring between the sensor connector and the ECU connector:
Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If all checks are correct, reconnect the ECU and the wheel speed sensor, then erase the ECU memory. Exit diagnostic mode (G13*) and switch the ignition off. Switch the ignition back on and replace the sensor if the fault reappears. If the fault reappears after replacing the sensor, replace the ECU. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
NOTES Even if present at the time of the check, these faults will always be reported by a flashing left or right BG8 bar graph.
To confirm their presence and therefore the need to apply the diagnosis below, carry out a road test. The fault is present if the bar graph comes on steady during the test.
If left bar graphs 6 and 8 are both on, address bar graph 6 first.
If right bar graphs 6 and 8 are both on, address bar graph 6 first.
| Check the wheel speed sensor mounting (position and tightening torque). Check the sensor/target air gap over one wheel revolution: 0.13 mm < air gap < 1.96 mm. Check that the target is compliant (condition, number of teeth = 26). |
| Check the connection and condition of the sensor connector. If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
| Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If the fault reappears after replacing the sensor, it may be caused by a faulty solenoid valve. Perform the hydraulic check of the solenoid valves with the XR25 diagnostic tool using command G03* or G04* (see the "help" chapter). If the ten release/hold cycles do not occur on one of the wheels, replace the hydraulic unit. If the hydraulic unit is not at fault, replace the control unit. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
NOTE Even if present at the time of the check, these faults will always be reported by a flashing left or right BG9 bar graph.
To confirm their presence and therefore the need to apply the diagnosis below, carry out a road test. The fault is present if the bar graph comes on steady during the test.
If left bar graphs 7 and 9 are both lit, deal with bar graph 7 first.
If right bar graphs 7 and 9 are both lit, deal with bar graph 7 first.
| Check the wheel speed sensor mounting (position and tightening torque). Check the connection and condition of the sensor connector. Check the connections at the underbody intermediate connection R101. If the connector is correct, check the sensor resistance at its connector. Replace the sensor if its resistance is not approximately 1.6 kOhm (1.6 kOhm ± 320 ohms). |
| Carry out a visual check of the sensor wiring and check the quality of the connections on the 31-pin ECU connector. |
| If all checks are correct, reconnect the control unit and the wheel speed sensor, then clear the control unit memory. Exit diagnostics (G13*) and carry out a road test. If the fault reappears, check the sensor/target air gap over one wheel revolution: 0.03 mm < air gap < 2.4 mm (this check can only be performed on vehicles with a 4-bar suspension). Check that the target is compliant: condition, number of teeth = 26. |
| If all checks are correct, exit diagnostics (G13*) and carry out a road test. Replace the sensor if the fault reappears. |
| If the fault reappears after replacing the sensor, it may be caused by a faulty solenoid valve. Perform the hydraulic check of the solenoid valves with the XR25 diagnostic tool using command G05* or G06* (see the "help" chapter). If the ten release/hold cycles do not occur on one of the wheels, replace the hydraulic unit. If the hydraulic unit is not at fault, replace the control unit. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
NOTE If right bar graph 10 is flashing, confirm the fault is present and therefore that the diagnostic below must be applied, by running command G20* on the XR25 diagnostic tool.
The fault is present if the bar graph lights steady again at the end of the command.
1.dEF
NOTE Replace the control unit if the pump motor runs continuously.
| Check the ABS earths (tightening of the two earth screws above the hydraulic unit). Check / ensure continuity between the ABS earth and pin 16 of the control unit connector. Check that the 2-way connector of the pump motor is locked. |
| If all checks are correct, reconnect the control unit, then clear its memory using command G0**. Exit diagnostics (G13*) and carry out a road test. Replace the control unit if the fault reappears. |
2.dEF
WARNINGS None.
Replace the hydraulic unit (mechanical seizure of the pump, ...).
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
WARNINGS None.
Carry out the necessary work to obtain a correct voltage between pins 19 and 17/18 of the ABS control unit 31-pin connector (9.4 volts < correct voltage < 17.4 volts):
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| If all checks are correct, reconnect the control unit, then clear its fault memory using command G0**. Exit diagnostics (G13*) and carry out a road test. Replace the control unit if the fault reappears. |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
WARNINGS None.
Press the brake pedal while monitoring bar graphs 13 right and left.Are the "pedal released" and "pedal depressed" positions correctly recognised?
| YES | Check both stop light bulbs and the earth of the rear light units (no earthing of pin 14 through the bulbs when the pedal is not depressed). |
| NO | Apply the diagnostic described in the interpretation of left and right bar graphs 13 for the case "left bar graph 13 off, brake pedal depressed". |
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
NOTE Even if present at the time of the check, this fault will always be reported by a flashing right BG12 bar graph.
To confirm its presence and therefore the need to apply the diagnostic below, carry out a road test. The fault is present if the bar graph lights steady during the test.
Check the mounting of the wheel speed sensors (position and tightening torque).Check that the targets are compliant: condition, number of teeth = 26.
AFTER REPAIR Erase the ECU memory (G0**).
Carry out a road test followed by a check with the XR25 tool.
NOTE Apply the checks only if the bar graph lighting is not consistent with the pedal position.
Left bar graph 13 off, brake pedal depressed
Bar graph 13 right therefore remains permanently lit.If the stop lights work:
- Ensure continuity between the dashboard / rear left R2 connection on pin 7 and pin 14 of the ABS control unit connector.
Dashboard / ABS intermediate connection R36 (pin 8).
If the stop lights do not work:
- Check the condition and adjustment of the brake light switch, as well as the 15A stop light fuse (in the passenger compartment interconnection box). Replace if necessary.
- Disconnect the brake light switch, then check / ensure the presence of + APC on pin A3 of the connector.
- Check the operation of the brake light switch contact (normally open contact between pins A3 and B1).
- Check and ensure continuity between pin B1 of the brake light switch connector and the dashboard / rear left R2 connection on pin 7.
Left bar graph 13 permanently lit
- Check the condition and adjustment of the brake light switch. Replace if necessary.
- Check the operation of the brake light switch contact (normally open contact between pins A3 and B1). Replace the brake light switch if there is continuity between these two pins at all times.
- Check and confirm insulation to 12 volts of the wiring between pin B1 of the brake switch connector and pin 14 of the ABS ECU connector.
Intermediate connections: Dashboard / ABS R36 at pin 8.
Dashboard / rear left R2 at pin 7.
AFTER REPAIR Carry out a road test, then check with the XR25 tool.
Test yourself
A quick Renault Kangoo quiz: every answer comes with an explanation and a link to the manual page.