Code tcs- U1016 need help
#2
Racer
U1016 Loss of Communication with PCM
Description:
The serial data circuit is used to communicate information between each system connected to the serial data line. Each system is assigned a specific recognition code (source ID). This code is used to identify which system is communicating on the serial data line. Systems communicate with others by periodically sending messages on the serial data line. These messages contain specific information (or commands) a system requires to function properly. When a system receives a message it also learns the source ID of the system that sent it. This source ID is used to determine which system actually sent the message and for State of Health (SOH) monitoring. SOH monitoring determines if a system is unable to communicate properly. Systems periodically send a SOH message to each other containing their source ID.
If a system fails to receive a SOH message back from a system that it communicates with, then a DTC identifying what system did not respond will set.
Conditions for setting:
● A system sends out a (SOH) message on the serial data line to the Powertrain Control Module (PCM) , and no SOH message response was sent back.
● Condition must be present for 5 seconds .
Diagnostic Aids:
● If the problem is an intermittent loss of communications. Carefully inspect the serial data line and related components for the following intermittent conditions:
● There is an intermittent open or short (to ground or voltage) in the serial data line.
● Intermittent loss of communication with the PCM.
● Damaged or loose star connector terminals.
● Poor connections/terminal tension at a harness connector.
● Intermittent PCM communication due to a loss of power or ground to the PCM.
● Communication DTCs do not necessarily indicate a malfunction. These DTCs are only intended to aid in diagnosing an intermittent communication malfunction that is accompanied by a symptom. If the vehicle does not experience a symptom related to a communication malfunction, these DTCs can be disregarded.
● If the serial data line is shorted to ground or shorted to voltage, all systems connected to the same serial data line will not be able to communicate properly. Systems capable of storing loss of communication DTCs (DTCs with the letter U as a prefix) will have these codes stored in their memory. If a DTC U1016 is stored in a system's memory, check for the same DTC stored in other systems capable of setting a DTC U1016. The IPC, RFA, LDCM, RDCM, and BCM all monitor the SOH message from the PCM. If other systems have a DTC U1016 stored, check the PCM for an intermittent malfunction. If other systems do not have a DTC U1016 stored, check for an intermittent malfunction in the system that set a DTC U1016. After repairing a DTC U1016, clear all DTCs from all systems capable of storing communication DTCs.
● If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur.
Possibilities:
1) you have an issue in your serial data bus; perhaps there is a loose connection along the serial data wire (single wire data bus if you are unaware)
2) you have a ground issue; Bill Curlee has a great post on inspecting and cleaning your ground connections here: http://forums.corvetteforum.com/1548189385-post1.html
3) there is some other issue that is "undiagnosed"
Questions:
1) are any other "U" codes coming up?
2) how many times has the described condition occurred?
3) does it happen every time?
4) what other indications are present when this condition occurs?
5) are any other codes set - either History or Current? If so, which ones?
6) what mods, if any, have you done recently? (I ask because I saw this same thread of yours in the General section after I posted all of this) So, anything in addition to the Vararam?
Disclaimer:
Having never experienced your exact condition, there is nothing immediate that I could hone in on and tell you to fix. With a little more information, I'm confident that your issue can be solved by either myself, someone else (such as Bill) or a combination of people here on the forum...
P.S. Sorry, but I am unable to post/add attachments (such as a circuit schematic or troubleshooting chart) from my iPad. If nobody beats me to it, I will try to post up the schematic and chart later today...
The serial data circuit is used to communicate information between each system connected to the serial data line. Each system is assigned a specific recognition code (source ID). This code is used to identify which system is communicating on the serial data line. Systems communicate with others by periodically sending messages on the serial data line. These messages contain specific information (or commands) a system requires to function properly. When a system receives a message it also learns the source ID of the system that sent it. This source ID is used to determine which system actually sent the message and for State of Health (SOH) monitoring. SOH monitoring determines if a system is unable to communicate properly. Systems periodically send a SOH message to each other containing their source ID.
If a system fails to receive a SOH message back from a system that it communicates with, then a DTC identifying what system did not respond will set.
Conditions for setting:
● A system sends out a (SOH) message on the serial data line to the Powertrain Control Module (PCM) , and no SOH message response was sent back.
● Condition must be present for 5 seconds .
Diagnostic Aids:
● If the problem is an intermittent loss of communications. Carefully inspect the serial data line and related components for the following intermittent conditions:
● There is an intermittent open or short (to ground or voltage) in the serial data line.
● Intermittent loss of communication with the PCM.
● Damaged or loose star connector terminals.
● Poor connections/terminal tension at a harness connector.
● Intermittent PCM communication due to a loss of power or ground to the PCM.
● Communication DTCs do not necessarily indicate a malfunction. These DTCs are only intended to aid in diagnosing an intermittent communication malfunction that is accompanied by a symptom. If the vehicle does not experience a symptom related to a communication malfunction, these DTCs can be disregarded.
● If the serial data line is shorted to ground or shorted to voltage, all systems connected to the same serial data line will not be able to communicate properly. Systems capable of storing loss of communication DTCs (DTCs with the letter U as a prefix) will have these codes stored in their memory. If a DTC U1016 is stored in a system's memory, check for the same DTC stored in other systems capable of setting a DTC U1016. The IPC, RFA, LDCM, RDCM, and BCM all monitor the SOH message from the PCM. If other systems have a DTC U1016 stored, check the PCM for an intermittent malfunction. If other systems do not have a DTC U1016 stored, check for an intermittent malfunction in the system that set a DTC U1016. After repairing a DTC U1016, clear all DTCs from all systems capable of storing communication DTCs.
● If the DTC is a history DTC, the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur.
Possibilities:
1) you have an issue in your serial data bus; perhaps there is a loose connection along the serial data wire (single wire data bus if you are unaware)
2) you have a ground issue; Bill Curlee has a great post on inspecting and cleaning your ground connections here: http://forums.corvetteforum.com/1548189385-post1.html
3) there is some other issue that is "undiagnosed"
Questions:
1) are any other "U" codes coming up?
2) how many times has the described condition occurred?
3) does it happen every time?
4) what other indications are present when this condition occurs?
5) are any other codes set - either History or Current? If so, which ones?
6) what mods, if any, have you done recently? (I ask because I saw this same thread of yours in the General section after I posted all of this) So, anything in addition to the Vararam?
Disclaimer:
Having never experienced your exact condition, there is nothing immediate that I could hone in on and tell you to fix. With a little more information, I'm confident that your issue can be solved by either myself, someone else (such as Bill) or a combination of people here on the forum...
P.S. Sorry, but I am unable to post/add attachments (such as a circuit schematic or troubleshooting chart) from my iPad. If nobody beats me to it, I will try to post up the schematic and chart later today...
Last edited by sunchaser73; 10-23-2012 at 07:58 AM. Reason: Added question #6
#3
thanks i will look at the posts on how to clean the grounds had it at the shop today he said he looked at the grounds said they were clean an maybe wanted to replace the EBCM.it happens only when i do about 75-80 or faster which i never do i live in new york so not much room to go any faster but anytime i take it out of gear doing those speeds it shuts off but the electronics stay on.other then the vararam i have the carbon fiber airbridge that has the MAT sensor drilled into it and B&B bullets an thats the only upgrades done to the car there are no other codes just that one the guy i know at the shop i go to said hes going to take the car friday and double check everything run all the computers and see if he sees anything but in the mean time ill also check the grounds myself and see what it could be