Code 51a6?

Hello,

Code 51A6 is a transmission control module-engine control module communication issue.
Usually, a bad or missing signal from the engine control module.
This can be caused by a bad crankshaft position sensor or damaged/corroded wiring.

The sensor is located on the bottom right of the transmission housing, see image below.
Suggest inspecting the wiring and connector to the sensor first.

Cheers, Boris

Changed CPS, but it is showing these codes.

More.

Hello,

Looking at the fault codes you still report a crankshaft sensor fault.
Are you sure that you replaced the correct sensor at the transmission housing?
You report replacing the CPS sensor, which is a camshaft position sensor.
See image below for the location of the CKP sensor.

The intelligent battery sensor is located at the negative terminal of the battery.
This sensor can also cause no start no crank issues.

See good video:
https://youtu.be/vl7BkzQBgHY

Cheers, Boris

Yes, i replaced the crank one by the transmission housing. Not OEM. Let me check the intelligent sensor.

Also, there is an aftermarket filter that is not installed properly, but the MAF is still in place, i would think regardless of connecting this tube it should run okay.

There is also some water on driver side floor that i noticed, is it possible something on the inside is shorting and causing this mess backward?

Hello,

This contraption of intake system should not cause starting or idling issues but keep in mind that this will cause contamination of the MAF sensor and the obvious dirt ingress into the engine.

I would certainly strip the carpet back and check any surrounding wiring, connectors and modules for possible corrosion.

Cheers, Boris

Cleaned out MAF and it started much better, RPM steady.

Still some codes, with the scan er still shows in limp mode Nd 3rd gear.

Can you check if this car has a fuse for the crank shaft position sensor? Also, i read some forums stating that their issue was solved after replacing the thermostat.

I checked wires on the crank sensor using a probe, one is ground, one battery voltage and the other just reads 10.3, does not say volts, does not beep or light up. i don't know if this is an issue.

Hello,

The crankshaft position sensor is supplied with 12V on orange wire from fuse F005(30A), see image 2 below.
The black/white wire is ground.
The yellow/white wire is the signal wire back to the DME pin 27, see image 3 below.
When the crankshaft sensor is disconnected then the DME will send a reverence voltage back up the signal wire.

How to test the sensor:
https://youtu.be/AacxF8dv_Sw

Cheers, Boris

What is a reverence you mean reference? But i have is 10.3 and does not say volts.

I also looked at where the ivm is which also contains the ECM, but could not see any fuses.

But since am getting 12v and ground it should be okay.

A new genuine crank shaft sensor has taken care of the code and it does not stall. Now i have to find a vacuum leak because there is a bit of rpm up/down when you first start it. I only drive it around my driveway and 1st and 2nd shifted so it's out of limp mode but did not shift 3rd not sure why yet.

Hello,

The best way of finding a vacuum leak is by using a smoke tester. A lot of people like spraying brake cleaner or carburetor cleaner to try find a leak but this can be hazardous as these liquids are flammable.
See image below regarding a smoke tester .

How to use a smoke tester:
https://youtu.be/LV2Cx41IccU

Cheers, Boris

Does the intelligent sensor have a fuse?

Hello,

I have searched a lot of documentation but cannot seem to find a fuse for the power supply for the IBS, intelligent battery sensor.

See image below for the sensor layout.

Cheers, Boris

What goes wrong with these? They fail on the inside?

Hello,

Yes, the IBS fails on the inside.

The intelligent battery sensor (IBS) is an intelligent, mechatronic component that monitors the battery condition.
The power supply to the IBS is provided through a separate wire.
For the purpose of data transmission, the IBS is connected to the digital engine electronics (DME) or digital diesel
electronics (DDE) via the bit serial data interface (BSD).
The intelligent battery sensor (IBS) consists of mechanical components, the electronics module and software.
- Mechanical components
The battery terminal with earth cable is the connection to the negative terminal of the battery and serves
· to create an electrical contact to the body
· as the support for the sensor element for current measurements
· as the support for the electronic module
· to provide an adequate thermal contact between the temperature sensor and the negative terminal of the battery
· as protection for the sensitive electronic module
· as an earth connection for the IBS

The mechanical parts are listed in image 1.

Electronic module:
The electronic module has the task of recording the voltage, the current flow and the temperature of the battery. The
following components are housed in the electronic module:
· a shunt (resistance for current measurement)
· a temperature sensor
· an electronic evaluation unit on a board
The board, which is about the size of a fingernail, contains an electronic circuit for evaluating the data measured.
The intelligent battery sensor (IBS) is able to withstand thermal loads of up to 105 °C and the chemical effect of the battery
acid. The IBS thus satisfies the necessary conditions for installation in the engine or luggage compartment.
The components of the shunt are illustrated below in image 2

How it works:
The functions of the intelligent battery sensor (IBS) are:
- To continuously measure battery data in all vehicle operating modes
- To compute battery indicators as basis for battery charge state (SoC: "State of Charge") and battery condition (SoH: State of Health")
- To balance the charge/discharge current of the battery
- To monitor the battery's charge state (SoC) and to activate the electric energy management and power management
for countermeasures if the battery charge state becomes critical (battery's limit of starting capability).
- To identify initial data for calibrating the battery charge state (SoC: "State of Charge")
- To calculate the starting current curve to determine the battery condition (SoH: "State of Health")
- To monitor off-load current
- To transmit data to the higher-order control unit (DME or DDE)
- Self-diagnosis
- To perform fully automatic updates of algorithm parameters and parameters for self-diagnosis via DME / DDE
- To be able to independently "wake up" from sleep mode


Cheers, Boris

Thanks.