Fault location tree
| ALP 1 | No communication with the ECU |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
| Make sure the diagnostic tool is not the cause of the fault by trying to communicate with an ECU on another vehicle. If the tool is not the cause and communication cannot be established with any other ECU on the same vehicle, a faulty ECU may be disturbing the multiplexed network. Check the battery voltage and carry out the necessary work to obtain a compliant voltage (9.5 volts < battery voltage < 17.5 volts). |
| Carry out a multiplexed network diagnosis using the diagnostic tool. |
| Check the presence and condition of the injection fuses on the UPC and in the engine fuse box. Check the connections of the control unit connectors and the condition of its terminals. Check the injection control unit earths (quality, corrosion, tightness of the earth screws on the battery terminal). Check that the ECU is correctly supplied:
|
Check that the diagnostic socket is correctly supplied:
|
| If communication still cannot be established after these checks, contact your techline. |
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 2 | The engine does not start |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 3 | The engine starts with difficulty or starts then stalls |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 4 | Difficult hot starting |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 5 | Unstable idle (surging) |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 6 | Idle speed too high / too low |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 7 | Unintentional acceleration / deceleration and engine overrun. |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 8 | Hesitation on acceleration and pick-up |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 9 | Engine shutdown / stalling |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 10 | Engine jerking |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 11 | Lack of power |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 12 | Excessive power |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 13 | Excessive consumption |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 14 | Overspeed on pedal release or gear change |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 15 | Engine stalls on take-off |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 16 | Engine does not stop |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 17 | Engine knocking, noisy engine |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 18 | Burst noise |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 19 | Miscellaneous mechanical noises |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 20 | Exhaust smell |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 21 | Diesel smell |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 22 | Blue, white, black smoke |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
| ALP 23 | Smoke (blue, white, black) on acceleration |
INSTRUCTIONS
Only refer to this customer complaint after a complete check with the diagnostic tool.
AFTER REPAIR
Carry out a road test, then a check with the diagnostic tool.
Test yourself
A quick Renault Megane quiz: every answer comes with an explanation and a link to the manual page.