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2004 Isuzu Rodeo - EVAP monitor not ready

7.2K views 2 replies 3 participants last post by  sissylala69s  
#1 ·
My car is a 2004 Isuzu Rodeo, direct injection.I live in California, and smog is due. So I took my car to smog check, but they wouldn't smog the car because the EVAP monitor is not ready. All other monitors (catalyst, O2 sensor are ready - the vehicle has no EGR valve also). The battery was replaced 1 month ago, which was probably what reset the tests.

Does anyone know the drive cycle? Or anyone have any tips to force the test? :)
 
#2 ·
I have the same problem with my 2001, I need the inspection completed by the end of this month but I cant't get the Evap Readiness Monitor to set ready. Any time you disconnect the battery or clear a DTC with a scan tool you reset the Readiness Monitors. My fuel level sender is sometimes erratic and that is probably causing the monitor test to abort during the drive cycle. I have swapped the filler cap and that did not fix it, I will try swapping the purge valve before I replace the sender unit. Part of the Evap monitor enabling criteria is the level be between 15-85 % full.

A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.