What do these codes mean.
Thread Starter
Instructor
Joined: Jul 2013
Posts: 224
Likes: 0
From: Worcester MA
What do these codes mean.
Started the Vett today and the check engine light came on,. When I checked the codes I had PCM P1220 H C and P1221 H C. Cleared them Check engine light turned off and I was on my way. Stopped at the gas station to get gas when I started the car check engine light came on again with the same 2 codes.
I did a quick search on the internet and found P1220= TP Sensor 2 Circuit and P1221= TP Sensor 1, 2 Performance.
Can any one elaborate as to what this actually means.
Thanks.
I did a quick search on the internet and found P1220= TP Sensor 2 Circuit and P1221= TP Sensor 1, 2 Performance.
Can any one elaborate as to what this actually means.
Thanks.
Drifting
Joined: Sep 2009
Posts: 1,719
Likes: 4
From: cinnaminson n.j.
St. Jude Donor '14
P1220
CIRCUIT DESCRIPTION
The Throttle Position (TP) sensor is mounted on the throttle body assembly. The sensor is actually 2 individual TP sensors within 1 housing. Two separate signal, low reference and 5-volt reference circuits are used in order to connect the TP sensor assembly to the Throttle Actuator Control (TAC) module. The 2 sensors have opposite functionality. The TP sensor 1 signal voltage is pulled up to the reference voltage as the throttle opens, from below 1 volt at closed throttle to above 3.5 volts at Wide Open Throttle (WOT) . The TP sensor 2 signal voltage is pulled down to the low reference from around 3.8 volts at closed throttle to below 1 volt at WOT. TP sensor 1 and APP sensor 1 share a 5-volt reference circuit that is connected within the TAC module. TP sensor 2 and APP sensor 2 share a 5-volt reference circuit that is connected within the TAC module. If an out of range condition is detected with the TP sensor 2, this DTC will set and the Reduced Engine Power message will be displayed.
CONDITIONS FOR RUNNING THE DTC
DTCs P1517, or P1518 are not set.
The ignition switch in the crank position or run the position.
The ignition voltage is greater than 5.23 volts .
CONDITIONS FOR SETTING THE DTC
The TP sensor 2 voltage is less than 0.13 volts or greater than 4.87 volts .
All above conditions present for less than 1 second .
ACTION TAKEN WHEN THE DTC SETS
The MIL is turned ON.
The Reduced Engine Power message is displayed.
A DTC is stored in memory.
The Freeze Frame/Failure Records are stored.
The Failure Records are updated after the first failure of each ignition cycle.
The control module will go into Reduced Engine Power mode and the APP indicated angle will be limited to a predetermined value for limited throttle control or the APP indicated angle will be limited to 0 and the engine will idle only. Under certain rare conditions the engine will be commanded to shut down.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the Malfunction Indicator Lamp (MIL) after the third consecutive trip the diagnostic has run and passed.
The history DTC will clear if the fault conditions have not been detected for 40 warm-up cycles.
A scan tool can be used to clear DTC information.
DIAGNOSTIC AIDS
Inspect the throttle actuator control (TAC) module connectors for signs of water intrusion. When water intrusion occurs, multiple DTCs could be set with no DTC circuit or component conditions found during diagnostic testing.
When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture info.
If this DTC is determined to be intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions
CIRCUIT DESCRIPTION
The Throttle Position (TP) sensor is mounted on the throttle body assembly. The sensor is actually 2 individual TP sensors within 1 housing. Two separate signal, low reference and 5-volt reference circuits are used in order to connect the TP sensor assembly to the Throttle Actuator Control (TAC) module. The 2 sensors have opposite functionality. The TP sensor 1 signal voltage is pulled up to the reference voltage as the throttle opens, from below 1 volt at closed throttle to above 3.5 volts at Wide Open Throttle (WOT) . The TP sensor 2 signal voltage is pulled down to the low reference from around 3.8 volts at closed throttle to below 1 volt at WOT. TP sensor 1 and APP sensor 1 share a 5-volt reference circuit that is connected within the TAC module. TP sensor 2 and APP sensor 2 share a 5-volt reference circuit that is connected within the TAC module. If an out of range condition is detected with the TP sensor 2, this DTC will set and the Reduced Engine Power message will be displayed.
CONDITIONS FOR RUNNING THE DTC
DTCs P1517, or P1518 are not set.
The ignition switch in the crank position or run the position.
The ignition voltage is greater than 5.23 volts .
CONDITIONS FOR SETTING THE DTC
The TP sensor 2 voltage is less than 0.13 volts or greater than 4.87 volts .
All above conditions present for less than 1 second .
ACTION TAKEN WHEN THE DTC SETS
The MIL is turned ON.
The Reduced Engine Power message is displayed.
A DTC is stored in memory.
The Freeze Frame/Failure Records are stored.
The Failure Records are updated after the first failure of each ignition cycle.
The control module will go into Reduced Engine Power mode and the APP indicated angle will be limited to a predetermined value for limited throttle control or the APP indicated angle will be limited to 0 and the engine will idle only. Under certain rare conditions the engine will be commanded to shut down.
CONDITIONS FOR CLEARING THE MIL/DTC
The control module turns OFF the Malfunction Indicator Lamp (MIL) after the third consecutive trip the diagnostic has run and passed.
The history DTC will clear if the fault conditions have not been detected for 40 warm-up cycles.
A scan tool can be used to clear DTC information.
DIAGNOSTIC AIDS
Inspect the throttle actuator control (TAC) module connectors for signs of water intrusion. When water intrusion occurs, multiple DTCs could be set with no DTC circuit or component conditions found during diagnostic testing.
When the TAC module detects a condition within the TAC System, more than one TAC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Disconnecting components during testing may set additional DTCs. Keep this in mind when reviewing the stored information, Capture info.
If this DTC is determined to be intermittent, refer to Intermittent Conditions. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Initial Inspection and Diagnostic Overview\Diagnostic Strategies\Intermittent Conditions
Racer
Joined: May 2011
Posts: 255
Likes: 2
From: Houston TX
I had the same codes, along with a couple others, after a header install. Turned out some wires got melted by the passenger side header. Fixed them and problem went away.
That said, it just happened again on Saturday while getting a hand wash. Unable to locate the cause so far.
That said, it just happened again on Saturday while getting a hand wash. Unable to locate the cause so far.
Thread Starter
Instructor
Joined: Jul 2013
Posts: 224
Likes: 0
From: Worcester MA
I ended up replacing the TPS, it was only $100 at the local store. Started the car a few times and all looks good so far won't really know until this weekend when I take it out for a drive.
