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Discussion Starter #1
Hi All
Didnt know wheather to put this on here or diagnostics. Is there anywhere I can get a list of the codes for a L322 2002 Range rover I am getting code 140 "Activation, map cooling" can anyone point me in the right direction. I have the Rave Cd but id doest seem to be on there!

Mick
 

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is it obdII code P00140?

if so this is what is explained for the obdII code P00140:

02 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
What does that mean?

The Powertrain control module (PCM) will provide a .45 volt reference voltage to the Oxygen sensor. When the O2 sensor reaches operating temperature, it will generate a voltage that will vary depending on the oxygen content of the exhaust. Lean exhaust generates a low voltage (less than .45V) and rich exhaust generates a high voltage (greater than .45V). O2 sensors on a specific bank marked as "sensor 2" (as this one is) are used to monitor emissions. A Three-Way Catalyst (TWC) system (catalytic converter) is used to control tailpipe emissions. The PCM uses the signal received from Oxygen sensor 2 (#2 indicates aft of catalytic converter, #1 indicates pre-converter) to read efficiency of TWC. Normally this sensor will switch between high and low voltage at a noticeably slower rate than the front sensor. This is normal. If the signal received from rear (#2) O2 sensor indicates that the voltage has "stuck" between .425V to .474 V, the PCM determines this sensor is inactive and this code will set.
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Potential Symptoms

Your check engine light(CEL), or malfuction indicator lamp (MIL) will be illuminated. There will not likely be any noticeable drivability problems other than the MIL. The reason is this: The rear or post catalytic converter Oxygen sensor does not affect fuel deliver(this is an exception on Chryslers). It only MONITORS the efficiency of the catalytic converter. For this reason, you will likely not notice any engine trouble.
Causes

The causes for a P0140 code are fairly few. They could be any of the following:

* Shorted heater circuit in O2 sensor. (Usually requires replacement of heater circuit fuse in fuse block also)
* Shorted signal circuit in O2 sensor
* Melting of harness connector or wiring due to contact with exhaust system
* Water intrusion in harness connector or PCM connector
* Bad PCM

Possible Solutions

This is a fairly specific problem and shouldn't be too difficult to diagnose.

First, start engine and warm up. Using a scan tool, watch the Bank 1, sensor 2, o2 sensor voltage. Normally the voltage should switch slowly above and below .45 volts. If it does, the problem is likely intermittent. You'll have to wait for the problem to surface before you can accurately diagnose.

However, if it doesn't switch, or is stuck then perform the following: 2. Shut off vehicle. Visually check the Bank1,2 harness connector for melting or chafing of the harness or the connector. Repair or replace as needed 3. Turn ignition on, but engine off. Disconnect the O2 sensor connector and check for 12Volts at the Heater Circuit supply and for proper ground on the heater circuit ground circuit. a. If 12V heater supply is missing, check the proper fuses for an open in the circuit. If heater circuit fuse is blown, then suspect a bad heater in the o2 sensor causing a blown heater circuit fuse. Replace sensor and fuse and recheck. b. If ground is missing, trace the circuit and clean or repair ground circuit. 4. Next, with connector still unplugged, check for 5 Volts on the reference circuit. If this is missing, check for 5 Volts at the PCM connector. If 5 Volts is present at the PCM connector but not at the o2 sensor harness connector, then there is an open or short in the reference wire supply between the PCM and the o2 sensor connector. However, if there is no 5 Volts present at the PCM connector, the PCM is likely at fault due to internal short. Replace PCM. ** (NOTE: on Chrysler models, a common problem is the 5Volt reference circuit can be shorted out by any sensor on the car that uses a 5 Volt reference. Simply unplug each sensor one at a time until the 5 Volts reappears. The last sensor you unplugged is the shorted sensor. Replacing it should fix the 5 Volt reference short.) 5. If all the voltages and grounds are present, then replace the Bank 1,2 O2 sensor and re-test.
 

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Discussion Starter #3
Hi thanks for the reply and wow what a reply. I will give you the full story.
I have just bought a 2002 BMW engined Mk 3 range rover and I love it, it has a Tartarini LPG installed. Unfortunatly the guy I bought it of forgot to tell me the engine light comes on after about 3 or 4 days of driving short distances about 50 or 60 miles.
I have bought a bought a hawkeye diagnostic system (Would have liked a BB but more than twice the price was to much). I am fairly confidant it is the gas system at fault but thought I would ensure the petrol is running right first.
The fault codes were 26, 62,53,56 and 140 the ones other than the 140 refer to missfires etc. these have cleared and do not return when driven on petrol.The code 140 (Thats all it says no prefix)says Activation, map cooling on searching the net I found an a BMW site "If the fault code 139 or 140 has been stored in the DME ensure the thermostat wiring and thermostat are functioning correctly. Repair any faults before reprogramming the DME". Is there a way of testing the electroic thermostat.
I have checked the Lambdas when running on the hawkeye and the are working okay. this code comes on the minute the engine is switched on hot or cold and does not put on the engine check light (not yet anyway).

Sorry for the long post and I hope it makes sense

Mick
 

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Discussion Starter #4
Re: fault codes (Uodate)

Hi All sorted now the code 140 is the electronic thermostat (Standard thermostst with a heater) Heater was open circuit fitted a new one all codes on pertol reset and staying off. Fault codes coming in on gas were bank 1 and 2 mixture adaption control limit reached. watched this output on the hawkeye and the gas was going to 25% where petrol reached about 18% this was at cruise at about 2200 revs (I guess this is leaning out of the mixture). tuned the gas using the tartarini software and bingo (Fingers crossed) no ecu faults.

Mick
 
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