When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
98 ML320 not completing rediness monitors - 80º C specification
I have been trying for over a month now to complete the drive cycle on this wonderful piece of engineering to no avail. All applicable readiness monitors complete with the exception of:
Secondary Air
Catalyst
EGR / VVT
I have read many drive cycle suggestions and the one thing that sticks out is the engine coolant temperature specification of 80º C. I am wondering just how tight this specification is. The best I can get is 76º C. Could that be the cause for those readiness tests not to run?
The only component in the vehicle replaced was the A/C clutch. Inspection is due 07/21. The question remains about the 80º specification on the engine coolant temperature for the readiness tests.
OK, three weeks ago I had the same problem after code P0410 and the monitors started off with 3 ready and 6 not. Driving around cleared 3 more ready and I was left with the same you have and they kept not ready.
Forget about temp. 80 & 83. Here is what I did...........
Got up early, 3AM, less trafic at that time, warmed up the eng for 5 mins. and got on a hwy. and drove at 55-60 RMP (I used cruise cont.) and stayed in the right or middle lane for 20 miles.
Got off hwy. and stopped for a few mins. (eng still running) and got back on the hwy. back home and drove the same way as described above.
OK, three weeks ago I had the same problem after code P0410 and the monitors started off with 3 ready and 6 not. Driving around cleared 3 more ready and I was left with the same you have and they kept not ready.
Forget about temp. 80 & 83. Here is what I did...........
Got up early, 3AM, less trafic at that time, warmed up the eng for 5 mins. and got on a hwy. and drove at 55-60 RMP (I used cruise cont.) and stayed in the right or middle lane for 20 miles.
Got off hwy. and stopped for a few mins. (eng still running) and got back on the hwy. back home and drove the same way as described above.
When I got home all monitors were ready.
The system needs to go from Open Loop to Closed Loop condition. This takes time and the vehicle generally must be driven. The warm up recommendations above should place the emission system in closed loop and show all sensors ready. If after changing the thermostat, the problem still exists, consider checking the temperature sensor circuit and replacing the sensor if necessary. The EGR, mass airflow sensor (MAF), oxygen sensor, engine temperature must all provide nominal inputs for the system to show ready.
Well, lets talk about that 80º specification. It does matter, period. My engine coolant temperature was reading only 76º C while challenging the readiness monitors. Nothing seemed to work for over a month. I decided to replace the thermostat and the operating temperature recovered to ~84-86º C. After about an hour the monitors were satisfied just sitting in the garage idling. The only one not to pass yet is the secondary air.. that is to be expected as this was the first start after replacing coolant
I recon I spoke too soon. As quick as the secondary air readiness cleared The MIL kicked in with a P0410 pending code. I'm thinking now that either one or both of the diverter valves (some call them combi valves or something else) are plugged up.
I realize that a slow O2 sensor could cause this but I have been looking at long and short term fuel trim and they look good as well as the O2 readiness clears rather quickly.
Here are the parts I speak of. Any tips or tricks of the trade as to removing and cleaning them?
If you are alluding to a bad blower motor I can rule that out. When I start the vehicle from stone cold, the RPMs immediately go to 1500-2000 for about two minutes and I can feel and hear the blower running. After that time duration, the motor drops to the proper idle speed and you can hear/feel the blower spin down.
If you are alluding to a bad blower motor I can rule that out. When I start the vehicle from stone cold, the RPMs immediately go to 1500-2000 for about two minutes and I can feel and hear the blower running. After that time duration, the motor drops to the proper idle speed and you can hear/feel the blower spin down.
- rev -
I'm not alluding to anything and I find it hard to work with you. I'm done hear, you figure it out, PERIOD.
WOW! What a surprise. I'm not quite sure what I said that pi$$ed you off but, after my post directed to you I took your advise and chased down the two red/wht wires and I do get a 12V reading upon starting from a cold start.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
