Keyless Entry: Testing and Inspection

TROUBLESHOOTING
HOW TO PROCEED WITH TROUBLESHOOTING

HINT: Troubleshooting of the wireless door lock control system is based on the premise that the door lock control system is operating normally. Accordingly, before troubleshooting the wireless door lock control system, first make certain that the door lock control system is operating normally.

Perform troubleshooting in accordance with the following procedure

FLOW CHART

No.1 CUSTOMER PROBLEM ANALYSIS
Using the customer problem analysis check sheet for reference, ask the customer in as much detail as possible about the problem.

No.2 PROBLEM SYMPTOM CONFIRMATION
No.3 SYMPTOM SIMULATION
Confirm the problem symptoms. If the problem does not reappear, be sure to simulate the problem, using the "Problem Simulation Method".

At this stage check whether the whole wireless door lock control system fails to operate, or whether only some of the particular functions fail to operate.

No.4 PRECHECK TYPE I
No.5 PRECHECK TYPE II
Using the self diagnosis function of the wireless door lock ECU, perform Precheck Type I to find out if the system is normal (system nonoperation due to external noise, etc.) or if the abnormality lies with the vehicle. In Precheck Type II, locate if the cause of problem lies in the transmitter, the antenna or the vehicle.

Perform Precheck Type I when whole wireless door lock control system fails to operate only at a specific locality.

Perform Precheck Type II when whole wireless door lock control system fails to operate no matter where the locality is.

When only some functions of wireless door lock control system do not operate, proceed to No.8 on the Matrix Chart of Problem Symptoms.

No.6 INSPECTION OF TRANSMITTER
No.7 INSPECTION OF ANTENNA CIRCUIT
If it is found in Precheck Type II that the cause of the problem is in the transmitter or antenna, proceed to the corresponding chart and start troubleshooting.

No.8 MATRIX CHART OF PROBLEM SYMPTOMS
Confirm the order of inspection for each applicable problem symptom on the matrix chart.

No.9 CIRCUIT INSPECTION
Proceed with diagnosis of each circuit in accordance with the inspection order confirmed in No.8. Judge whether the cause of the problem is in the sensor, wire harness and connectors, or the ECU.

No.10 REPAIR
If the cause of the problem is found in No.9, perform repairs.

No.11 CONFIRMATION TEST
After completing repairs, confirm that the problem is eliminated and that all functions of the wireless door lock control system are normal.

MATRIX CHART OF PROBLEM SYMPTOMS
Perform troubleshooting of the circuits for the applicable problem symptom in the order given in the chart below.

HINT:
^ Troubleshooting of the wireless door lock control system is based on the premise that the door lock control system is operating normally. Accordingly, before troubleshooting the wireless door lock control system, first make certain that the door lock control system is operating normally.
^ If the instruction "Proceed to next circuit inspection shown on matrix chart" is given in the flow chart for each circuit, proceed to the circuit with the next highest number in the table to continue the check.
^ If the trouble still reappears even though there are no abnormalities in any of the other circuits, then check and replace the Wireless Door Lock ECU as the last step.

No.1 SYSTEM CHECK SHEET

N0.2/3 SYMPTOM SIMULATION
The most difficult case in troubleshooting is when there are no problem symptoms occurring. In such cases, a thorough customer problem analysis must be carried out, then simulate the same or similar conditions and environment in which the problem occurred in the customer's vehicle. No matter now much experience a technician has, or how skilled he may be, if he proceeds to troubleshoot without confirming the problem symptoms he will tend to overlook something important in the repair operation and make a wrong guess somewhere, which will only lead to a standstill. For example, for a problem which only occurs when the engine is cold, or for a problem which occurs due to vibration caused by the road during driving, etc., the problem can never be determined so long as the symptoms are confirmed with the engine hot condition or the vehicle at a standstill. Since vibration, heat or water penetration (moisture) are likely causes for problems which are difficult to reproduce, the symptom simulation tests introduced here are effective measures in that the external causes are applied to the vehicle in a stopped condition.

Important Points in the Symptom Simulation Test

In the symptom simulation test, the problem symptoms should of course be confirmed, but the problem area or parts must also be found out. To do this, narrow down the possible problem circuits according to the symptoms before starting this test and connect a tester beforehand. After that, carry out the symptom simulation test, judging whether the circuit being tested is defective or normal and also confirming the problem symptoms at the same time. Refer to the matrix chart of problem symptoms for each system to narrow down the possible causes of the symptom.