Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Cruise control system / Idle signal circuit
Toyota Corolla (E120): Idle signal circuit
Dtc 51 idle signal circuit
Other materials:
Valve clearance
Adjustment
1. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
2. Disconnect engine wire
Remove the 5 clamps from the 5 clamp brackets.
Disconnect the 4 ignition coil connectors.
Remove the bolt and nut installing the engine wire ...
Evap monitor (vacuum pressure monitor)
Notice:
a cold soak must be performed prior to conducting the drive pattern to complete
the internal pressure
readiness monitor.
Cold soak preconditions
The monitor will not run unless:
mil is off.
Fuel level is approximately 1/2 to 3/4.
Altitude is 7800 feet (2400 m) or less.
...
Circuit description
When a misfire occurs in the engine, hydrocarbons (hc) enter the exhaust in
high concentrations. If this hc
concentration is high enough, there could be an increase in exhaust emissions
levels. High concentrations
of hc passing through the catalyst also cause to temperature of the catalyst to ...