The hydraulic pump relay is vital for the transmission pump’s operation, so an abnormally high voltage reading often indicates an electrical issue somewhere along the circuit. In this scenario, the ECU records a DTC P0948.

How severe is the code?

Diagnostic code P0948 is very serious, as it indicates the likelihood of an electrical problem along the hydraulic pump circuit. This can lead to a number of driving issues, which may result in very serious/costly repairs if not diagnosed.

Symptoms

Symptoms of a P0948 include:

• Harsh shifts
• Slipping
• Failed shifts

Causes

• Transmission fluid is too low or too dirty
• Damaged wiring
• Corroded or broken connectors
• Hydraulic pump relay failure
• ECU or TCM issues

How to diagnose the code?

The diagnostic process for an OBDII fault code P0948 obviously involves checking the transmission pump relay. But the level and condition of the transmission fluid, as well as the state of the wiring and connectors along the transmission wiring harness, can also trigger this OBD2 code.

What repairs will fix P0948?

• Change the transmission fluid/filter
• Repair or replace damaged wiring and/or connectors
• Replace the hydraulic pump relay
• Reprogram or replace the ECU/TCM

Whenever you work on your transmission or install a new car battery, the ECU must complete a process called adaptive learning, where the computer and transmission essentially synchronize. If this process was not completed for any reason, a DTC P0949 will be recorded.

How severe is the code?

Diagnostic code P0949 is not extremely severe, but the driving issues associated with it can be extremely annoying.

Symptoms

Symptoms of a P0949 include:

Irregular shifting

Causes

Transmission adaptive learning procedure not completed

How to diagnose the code?

If your vehicle has an OBDII trouble code P0949, a technician will need to connect the diagnostic computer to the vehicle’s OBD2 port, then reset the ECU to adaptive learning mode.

What repairs will fix P0949?

Complete transmission adaptive learning procedure

P094A, P094B, P094C, P094D, P094E, P094F ISO/SAE Reserved

P034A, P034B, P034C, P034D, P034E, P034F ISO/SAE Reserved

If your vehicle has a manual shift function on its automatic transmission, you will be able to manually control gear shifts by placing the gear lever in a special gate next to the PRNDL labels. However, if there is a problem with the electrical circuit that allows this to happen, a DTC P0950 will be recorded.

How severe is the code?

Having a diagnostic code P0950 will not significantly impact the vehicle’s driving, nor cause internal damage. However, you will likely not be able to manually shift the transmission.

Symptoms

Symptoms of a P0950 include:

• The manual shift function is disabled

Causes

• Damaged wiring or connectors
• Failure of the shift switch

How to diagnose the code?

An OBDII trouble code P0950 is often caused by damaged wiring or corroded connectors, due to spilled fluids around the gear lever. Therefore, all cables and connectors around the shift mechanism should be checked for signs of damage and corrosion. The transmission shift switch itself should also be checked.

What repairs will fix P0950?

• Repair or replace damaged wiring and connectors
• Replace the transmission shift switch

Vehicles with manual-shift automatic transmissions allow you to manually downshift and upshift, thanks to a number of transmission parts that include a switch on the gear selector, an actuator, and a bunch of wiring. A DTC P0951 means that a component in this collective circuit is not functioning according to preprogrammed parameters.

How severe is the code?

Diagnostic code P0951 is not particularly severe. However, you will not be able to manually control gear shifts using the manual gear selector or paddles.

Symptoms

Symptoms of a P0951 include:

• Manual shifting function is disabled

Causes

• Damaged wiring and/or connectors
• Failure of the shift switch

How to diagnose the code?

The diagnostic process for an OBDII fault code P0951 usually begins with an inspection of the wiring and connectors around the shift assembly. If no broken/frayed cables are corroded/broken, then the manual shift switch on the transmission/up and down shift switch should be tested and checked for signs of water damage.

What repairs will fix P0951?

• Repair or replace damaged wiring and connectors
• Replace the transmission shift switch

Thanks to technological advancements, many automatic transmissions cannot be manually controlled by shifting the gear lever up/down or pressing the shift paddles behind the steering wheel. This process is controlled by a number of sensors, actuators, and wires. If there is a low-level signal from this circuit of components, a DTC P0952 will be recorded.

How severe is the code?

A diagnostic trouble code P0952 is not very severe, but you will not be able to manually control the transmission using the gear selector or the steering wheel ‘+/-‘.

Symptoms

Symptoms of a P0952 include:

• Manual shift function is disabled

Causes

• Wiring damage
• Corroded or broken connectors
• Shift switch failure

How to diagnose the code?

When trying to diagnose an OBDII fault code P0952, it is important to start by inspecting the entire gear lever for signs of water damage due to spills around the gear lever. The wiring and connectors should be checked for signs of damage and corroded connectors. The manual shift switch itself should also be tested.

What repairs will fix P0952?

1. Repair or replace damaged wiring and connectors
2. Replace the transmission shift switch

The manual shift automatic control circuit/Autostick manual control circuit consists of sensors, wires, and connectors that allow you to manually control your automatic transmission. A DTC P0953 means there is an abnormally high voltage signal somewhere in this circuit.

How severe is the code?

Diagnostic code P0953 does not mean you will be stranded on the side of the road. However, it does mean you will not be able to manually control gear shifts.

Symptoms

Symptoms of a P0953 include:

    Manual shift function is disabled

Causes

    Damaged connectors and/or wiring
    Shift switch failure

How to diagnose the code?

The process of determining the cause of a P0953 OBDII trouble code usually begins with inspecting the entire shift lever assembly. Water damage to the Autostick switch and connectors is a common cause. Wiring should also be checked for damage such as frayed or broken wires.

What repairs will fix P0953?

    Repair or replace damaged wiring and connectors
    Replace the transmission shift switch

If your vehicle is equipped with an Autostick transmission/Tiptronic transmission (there are also many other brand-specific names), you can manually control the shift points using a special gate on the gear lever or paddles/buttons on the steering wheel. If there is an intermittent electrical issue in the circuit that includes a transmission shift switch, a mode actuator, and a bundle of wires and connectors, a DTC P0954 will be recorded by the ECU.

How severe is the code?

Having a diagnostic code P0954 is not very serious. It simply means you won’t be able to use the manual shift function.

Symptoms

Symptoms of a P0954 include:

    The manual shift function is disabled

Causes

    Damaged connectors or wiring
    Shift switch failure

How to diagnose the code?

To determine what is causing the OBDII fault code P0954, your mechanic should start by checking the shift mechanism for signs of water damage from spills. The shift switch needs to be tested, and the wiring/connectors should be inspected for signs of damage and corrosion.

To change an automatic transmission like a manual one, a switch connected to the gear lever must send an electrical signal to the TCM whenever you push the gear lever in the +/- direction. This tells a sensor on the valve body which gear you want to engage. If there is a problem with any of the components in the automatic transmission manual shift mode circuit, a DTC P0955 will be recorded.

How severe is the code?

Transmission issues related to a diagnostic code P0955 will likely not leave you stranded on the side of the road. However, they will prevent you from using the manual shift function.

Symptoms

Symptoms of a P0955 include:

• Manual shift function disabled

Causes

• Damaged wiring or connectors
• Failure of the Autostick transmission shift switch

How to diagnose the code?

To diagnose an OBDII fault code P0955, your mechanic will need to check the gear lever mechanism for signs of moisture damage, due to possible spills around the gear lever. The Autostick shift switch must be tested to ensure it is functioning, and the wiring/connectors should be checked for signs of damage and corrosion.

What repairs will fix P0955?

1. Repair or replace damaged wiring and connectors
2. Replace the Autostick transmission shift switch

To ensure manual control of an automatic transmission, a number of sensors, actuators, and wires are used. If any component in this circuit does not function according to preprogrammed parameters, a DTC P0956 will be recorded.

How severe is the code?

If your vehicle has a diagnostic code P0956, you probably won’t need to call a tow truck. However, you likely won’t be able to manually control the transmission using the manual gear selector or paddles.

Symptoms

Symptoms of a P0956 include:

• Disabling the manual shifting function

Causes

• Corroded or broken connectors
• Wiring damage
• Failure of the Autostick transmission shift switch

How to diagnose the code?

Diagnosing an OBDII P0956 code typically involves inspecting the shifting mechanism for signs of water damage/corrosion around the connectors and the autostick switch. The transmission shift switch itself must be tested to ensure it is functioning, and all wiring should be inspected for any signs of damage.

What repairs will fix P0956?

• Repair or replace damaged wiring and connectors
• Replace the Autostick transmission shift switch