P0073 - Ambient Air Intake Temp Sensor
#1
P0073 - Ambient Air Intake Temp Sensor
I got this code so I checked to make sure that I had continuity to the sensor and I did. When I checked the sensor itself it did raise and lower (starting at about 6k ohms) with temp change (breath applied to the sensor). So, I bought a new one and installed it and cleared the code. A couple of days later the light returned. Before I go through it all again I wanted to see if anyone else had this problem and if I need to be concerned with the engine management system. I did check the new sensor before I put it in and it started at about 10k ohms. Did I get a bad sensor? Thanks in advance for your help. rich
#4
The sensor is mounted in the intake hose between the air filter and intake manifold. The parts people also referred to it as the charge air temp sensor. Basically, my understanding is that it is suppose to measure the temp of the incoming air and the EMS makes adjustments to the fuel mix accordingly.
#5
New info - I tested the voltage going to each of the connectors coming from the EMS (engine management system) and got 5.0 mv on one side and 4.97 volts on the other. I did this by connecting the negative lead of my volmeter to the negative post of the battery and then to each of the connectors in the clip. I checked all of the harnesses (without removing the protectors) and found no wear patterns or breaks. Since it is unlikely (but not impossible) that the new sensor is the culprit - do I have an EMS problem or should I be looking at the wiring more closely? Thanks in advance.
#6
P0073-AMBIENT TEMP SENSOR HIGH
When Monitored: The ignition key on.
Set Condition: The Ambient Temperature Sensor voltage is greater than 4.94 volts. One
Trip Fault.
POSSIBLE CAUSES
AMBIENT AIR TEMPERATURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
(K25) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
AMBIENT AIR TEMPERATURE SENSOR INTERNAL FAILURE
(K25) AAT SIGNAL CIRCUIT OPEN
(K4) SENSOR GROUND CIRCUIT OPEN
PCM
ok u got the 5v on the power side now u need to make sure u have the ground on the other with when the key on. This ground is an internal ground in the pcm Its not a pcm issue because that same ground ckt is for the TPS and crank sensor and they dont have issues so I would look for a broken ground circuit back to the pcm.
When Monitored: The ignition key on.
Set Condition: The Ambient Temperature Sensor voltage is greater than 4.94 volts. One
Trip Fault.
POSSIBLE CAUSES
AMBIENT AIR TEMPERATURE SENSOR VOLTAGE ABOVE 4.8 VOLTS
(K25) AAT SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
AMBIENT AIR TEMPERATURE SENSOR INTERNAL FAILURE
(K25) AAT SIGNAL CIRCUIT OPEN
(K4) SENSOR GROUND CIRCUIT OPEN
PCM
ok u got the 5v on the power side now u need to make sure u have the ground on the other with when the key on. This ground is an internal ground in the pcm Its not a pcm issue because that same ground ckt is for the TPS and crank sensor and they dont have issues so I would look for a broken ground circuit back to the pcm.
#7
Hey TECH! This is GREAT info! I am greatful for your help. I will commence tracing the wires - I assume the lead that gave me the 5.0 mili-volts is the ground since the other gave me the 4.7 volts (the power lead). It sounds like it might have come in contact with some other power line. I will keep u posted and thanks again! Rich
#8
K - I checked and I do have a good ground on the ground side of the sensor clip. But do you think that those 5 mili-volts on that side is causing it to fault? (Pushing the monitored voltage over limits?) The harnes looks good all the way through so I guess I have something going on internally somewhere. I'll keep looking and keep you posted. Don't you just love gremlins? Thanks again! Rich
#9
K - the gremlins multiply!!!! Since I had a good ground and good voltage on the power side I concluded that the sensor must be bad. Soooo I exchanged it for a new one. Guess what? Now I have the same code (p0073) AND a new one P0113. This thing is driving me crazy ... any ideas? Thanks in advance. Rich
#10
Problem solved! Initially the dealer parts man told me to check/replace the WRONG sensor. The p0073 code has to do with the sensor up under the bumper (which turned out just have a broken wire - the wire is naturally exposed). What ended up solving it was when I got a new sensor from the dealer to replace the one I thought was bad - the new one WAS bad and it threw the new code ... My haynes manual was toatally useless and the dealer parts man was destructive. Now, I have an extra sensor (that will probably never go bad) that they were REALLY proud of ($28) ... thanks TECH for at trying to help me with my BAD information. Rich