Honda CR-V: Exhaust Emissions Controls
The exhaust emissions controls include three systems: PGM-FI, ignition timing control, and three way catalytic converter. These three systems work together to control the engine’s combustion and minimize the amount of HC, CO, and NOx that comes out the tailpipe. The exhaust emissions control systems are separate from the crankcase and evaporative emissions control systems.
PGM-FI System
The PGM-FI system uses sequential multiport fuel injection.
It has three subsystems: air intake, engine control, and fuel control. The powertrain control module (PCM) uses various sensors to determine how much air is going into the engine. It then controls how much fuel to inject under all operating conditions.
Ignition Timing Control System
This system constantly adjusts the ignition timing, reducing the amount of HC, CO, and NOx produced.
ThreeWay Catalytic Converter
The three way catalytic converter is in the exhaust system. Through chemical reactions, it converts HC, CO, and NOx in the engine’s exhaust to carbon dioxide (CO2), nitrogen (N2), and water vapor.
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Replacement Parts
The emissions control systems are
designed and certified to work together
in reducing emissions to
levels that comply with the Clean Air
Act. To make sure the emissions
remain low, you shoul
ThreeWay Catalytic Converter
The three way catalytic converter
contains precious metals that serve
as catalysts, promoting chemical
reactions to convert the exhaust
gasses without affecting the metals.
The catalytic conv
Emissions Testing
Testing of Readiness Codes
If you take your vehicle for an
emissions test shortly after the
battery has been disconnected or
gone dead, it may not pass the test.
This is because of certain ‘
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DTC 51: Motor Locked
1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Test-drive the vehicle. Drive the vehicle at 10 mph
(15 km/h) or more, with the engine speed at
2,500 rpm or more.
4. Check for DTCs with the HDS.
Is DTC 51 indicated?
YES-Replace the VSA modulator-control unit.
NO-Intermitt
Horns
Component Location Index
HORN
HORN SWITCH
HORN RELAY CIRCUIT
(Built into the MICU)
CABLE REEL
UNDER-DASH FUSE/RELAY BOX
Circuit Diagram
Horn Switch Test
1. Remove the steering column covers.
2. Disconnect the dashboard wire harness 20P
connector (A) from the cable reel (B).
3. Usin
