The Honda Accord vehicle cannot start, the anti-start light is on when the ignition switch is in the start gear, the starter rotates but does not start, and the anti-start unit light does not light up when the ignition switch is in the ON gear.
Real vehicle diagnosis process:
Connect the vehicle with HDS. Check the PFM-FI system, DTC is P060A, PCM internal module control failure, and electronic throttle closing failure. The anti-start system has no DTC, and other systems have no DTC.
According to the maintenance manual, the authorized store checked the fault code according to the process, checked all the iron wires, replaced the PCM, the driver's MICU, and the anti-start unit, etc. The fault was not resolved.
When the technician's thinking reached a deadlock, he accidentally removed the 4 ignition coils to start the engine, and the anti-start unit was no longer lit at this time. After replacing 4 ignition switches, the fault was solved.
Correct diagnosis ideas:
It is not uncommon for vehicles to have DTC P060A and PCM internal module control failures. After this problem occurs, the general process of the authorized store technician is to replace the PCM, and then check the fault according to the DTC P060A treatment method given in the maintenance manual, but the problem generally cannot be resolved.
IGP open circuit will cause DTC PCM internal fault, IGIETCS open circuit will cause DTC electronic throttle closing fault. If only one of these two fault codes appears, it may be a single line problem, but two DTCs appear at the same time, generally, we think it is caused by the sudden low voltage of the system. The reason that can cause the low voltage of the system is generally caused by the momentary short circuit of large-scale electrical appliances, such as ignition coils, batteries, xenon headlights, etc.
The problem with this car is a short circuit in the ignition coil.