Car is stuck in limp mode
12-27-2023, 08:37 PM
#1
Car is stuck in limp mode
Hey car is in limp mode I don’t know why I put long tube headers in the car got the longer extensions for the 02 sensors fully tuned and I was driving it the other day just doing pulls then car threw a p0643 I checked every connection i disconnected the battery and put it back and it drove fine then it threw a p0031 code for the 02 sensor bank 1 sensor 1 it was Christmas Day so no stores were open I just took the sensor out i replaced it with a used one didint fix the issue the car was drivable just not well next day I drove to auto zone got the new 02 sensor put it in and automatically car went into limp mode and threw p0643 sensor reference voltage a circuit high it turned on and was stuck in limp mode I checked every connection I checked the 02 extension harnesses everything is fine and connected I can’t tell what else it can anything can help car won’t even start now last night I tried to drive it in limp mode up the block to my house and it died while just rolling any help please and thank you
12-27-2023, 10:02 PM
#2
Premier Member
One of the first things you can do is search the forum to see if anyone else has had the same problem before and perhaps there could be a solution.
Most of the active members can be helpful, but there are limits to troubleshooting a complex problem remotely. Most of the advice will be standard fare (see my advice below).
The real advantage to a group like this resides in the historical files that go way back. Thats why the best first step is to search for your problem (both on here and on The370Z forum for powertrain related issues)
From you message it appears that the issue showed up right after the header install and tune?
Most likley scenario is some wiring or conector was damaged when the headers were installed. Another idea is a connector may be disconnected or loose in the socket.
P0643 refers to the ECM finding a power problem for one (or more) of multiple sensors.
Here is the list of possibles for P0643 from the FSM,
Harness or connectors (APP sensor 1 circuit is shorted.) (TP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 1) circuit is shorted.] [Manifold absolute pressure (MAP) sensor circuit is shorted.] (PSP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 2) circuit is shorted.] [Battery current sensor circuit is shorted.]
• Accelerator pedal position sensor • Throttle position sensor • Camshaft position sensor (PHASE) (bank 1) • Manifold absolute pressure (MAP) sensor • Power steering pressure sensor • Camshaft position sensor (PHASE) (bank 2) • Battery current sensor
You might try contacting the tuner to find out if they can help.
Most of the active members can be helpful, but there are limits to troubleshooting a complex problem remotely. Most of the advice will be standard fare (see my advice below).
The real advantage to a group like this resides in the historical files that go way back. Thats why the best first step is to search for your problem (both on here and on The370Z forum for powertrain related issues)
From you message it appears that the issue showed up right after the header install and tune?
Most likley scenario is some wiring or conector was damaged when the headers were installed. Another idea is a connector may be disconnected or loose in the socket.
P0643 refers to the ECM finding a power problem for one (or more) of multiple sensors.
Here is the list of possibles for P0643 from the FSM,
Harness or connectors (APP sensor 1 circuit is shorted.) (TP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 1) circuit is shorted.] [Manifold absolute pressure (MAP) sensor circuit is shorted.] (PSP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 2) circuit is shorted.] [Battery current sensor circuit is shorted.]
• Accelerator pedal position sensor • Throttle position sensor • Camshaft position sensor (PHASE) (bank 1) • Manifold absolute pressure (MAP) sensor • Power steering pressure sensor • Camshaft position sensor (PHASE) (bank 2) • Battery current sensor
You might try contacting the tuner to find out if they can help.
The following users liked this post:
Helpmewithmycar (12-27-2023)
12-27-2023, 10:05 PM
#3
One of the first things you can do is search the forum to see if anyone else has had the same problem before and perhaps there could be a solution.
Most of the active members can be helpful, but there are limits to troubleshooting a complex problem remotely. Most of the advice will be standard fare (see my advice below).
The real advantage to a group like this resides in the historical files that go way back. Thats why the best first step is to search for your problem (both on here and on The370Z forum for powertrain related issues)
From you message it appears that the issue showed up right after the header install and tune?
Most likley scenario is some wiring or conector was damaged when the headers were installed. Another idea is a connector may be disconnected or loose in the socket.
P0643 refers to the ECM finding a power problem for one (or more) of multiple sensors.
Here is the list of possibles for P0643 from the FSM,
Harness or connectors (APP sensor 1 circuit is shorted.) (TP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 1) circuit is shorted.] [Manifold absolute pressure (MAP) sensor circuit is shorted.] (PSP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 2) circuit is shorted.] [Battery current sensor circuit is shorted.]
• Accelerator pedal position sensor • Throttle position sensor • Camshaft position sensor (PHASE) (bank 1) • Manifold absolute pressure (MAP) sensor • Power steering pressure sensor • Camshaft position sensor (PHASE) (bank 2) • Battery current sensor
You might try contacting the tuner to find out if they can help.
Most of the active members can be helpful, but there are limits to troubleshooting a complex problem remotely. Most of the advice will be standard fare (see my advice below).
The real advantage to a group like this resides in the historical files that go way back. Thats why the best first step is to search for your problem (both on here and on The370Z forum for powertrain related issues)
From you message it appears that the issue showed up right after the header install and tune?
Most likley scenario is some wiring or conector was damaged when the headers were installed. Another idea is a connector may be disconnected or loose in the socket.
P0643 refers to the ECM finding a power problem for one (or more) of multiple sensors.
Here is the list of possibles for P0643 from the FSM,
Harness or connectors (APP sensor 1 circuit is shorted.) (TP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 1) circuit is shorted.] [Manifold absolute pressure (MAP) sensor circuit is shorted.] (PSP sensor circuit is shorted.) [CMP sensor (PHASE) (bank 2) circuit is shorted.] [Battery current sensor circuit is shorted.]
• Accelerator pedal position sensor • Throttle position sensor • Camshaft position sensor (PHASE) (bank 1) • Manifold absolute pressure (MAP) sensor • Power steering pressure sensor • Camshaft position sensor (PHASE) (bank 2) • Battery current sensor
You might try contacting the tuner to find out if they can help.
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