C5 III Heavy Steering

[ThoreT]

My C5 III steering has become heavy. It is steel sprung, and has the electro pump. I had a leaking steering rack, I thought this was the culprit, and had it replaced. The problem, however, persisted. It does get servo assist, but the steering is heavier than what it should be.

I've had a full check of the front suspension, jacked the front up and started the engine to check for any friction in the steering wheel assembly (it was nice and light), and checked the connectors at the pump (they were nice and shiny).

I guess this leads to a problem with the pump itself? Or could it be a communication problem with the BSI? Does the pump go into a default mode if BSI velocity or steering angle rate data are
unambiguous or missing?

The pump has part number 9673017080. I've found several new or reman 9673173780. It seems to have the same specs, connector configuration, is specified for the same model vehicle, year/month and engine type. Would it be OK to use this pump?

- Thore

[GiveMeABreak]

Hi Thore, I have responded to your request in the parts thread.

Be aware that the power steering is directly powered via the car's 12V battery. If the battery is in a weakened state or in poor health (anything over 5 years), then it may not be providing sufficient power for the steering system.

Also, make sure you bleed the system. Here is the procedure for the Metallically sprung vehicles with electric power steering pump:

• Start the engine.
• Turn on the engine and let it idle for 2 to 3 minutes, without moving the steering wheel (Top up with oil if necessary).
• Move the steering slowly, from stop to stop, in both directions, 10 or so times, with the wheels on the ground.
• N.B.: Do not hold the steering on the stop in order to prevent the opening of the pressure limiter.
• Check there are no bubbles in the tank.
• Top up the power steering fluid to the maximum level of the tank.
• If some bubbles are present in the tank, allow it to degas completely ( 3 to 5 minutes), engine running without moving the steering wheel.
• Carry out 5 new movements of the steering slowly, from stop to stop, in both directions, with the wheels on the ground.
• Repeat this phase until the bubbles completely disappear from the surface of the fluid in the tank.
• Carry out a road test and check the level of power steering fluid (With the engine stopped, and the cap screwed on, oil temperature 30°C).
• N.B.: There must be no bubbles in the tank, otherwise repeat the bleeding procedure.

[ThoreT]

Thank you Marc

I already did the bleeding procedure you described. The battery is new as of last year, and of a high quality brand.

Is the voltage input to the pump constant (through the beefy two-lead connector)? I assume the smaller three-lead connector receives data from the BSI, and this in turn is processed by the pump circuitry to regulate pump RPM....

-Thore

[GiveMeABreak]

There can be an issue with the power assistance (lack of effectiveness) if you are getting fault code C1178. Lack of effectiveness can be when driving off or when driving.

The larger 2 pin plug is for the power supply and the 5 pin plug has 3 pins in use for the CAN network and ignition +.

The system has electronics to monitor fluid temperature and other factors.

If the fault is present, then suggestion is to check the power supply on the 2 pin plug using a 55 Watt inspection lamp. Pin 1 is 12V, Pin 2 is Earth.

If that complies, then the ignition+ on the 5 pin connector should be checked with a 21 Watt inspection lamp. Pin 3 is the ignition+.

If both conform, then the it means the power steering electro unit needs replacing.

[ThoreT]

Thank you Marc

I do not see that fault code. Looking at the maintenance manual, section D4EA01NSP0 - Description of back-up mode, Electro Hydraulic Power steering, it states that lack of steering wheel speed of rotation information will result in a progressively fixed speed of rotation value, which in turn will lead to reduced steering assistance. But, I guess a bad steering angle sensor would result in a host of other problems and fault codes? Or, is there a specific signal from the angle sensor that only gives angular rate that could have failed?

I did get hold of a used servicable pump for a good price, thank you for giving me the part number information.

-Thore

[GiveMeABreak]

If there was a problem with the steering wheel angle sensor it would be returning a faulty code independently and you'd be getting ESP warnings too.

[fcesur77]

My C5 III steering has become heavy. It is steel sprung, and has the electro pump. I had a leaking steering rack, I thought this was the culprit, and had it replaced. The problem, however, persisted. It does get servo assist, but the steering is heavier than what it should be.

I've had a full check of the front suspension, jacked the front up and started the engine to check for any friction in the steering wheel assembly (it was nice and light), and checked the connectors at the pump (they were nice and shiny).

I guess this leads to a problem with the pump itself? Or could it be a communication problem with the BSI? Does the pump go into a default mode if BSI velocity or steering angle rate data are
unambiguous or missing?

The pump has part number 9673017080. I've found several new or reman 9673173780. It seems to have the same specs, connector configuration, is specified for the same model vehicle, year/month and engine type. Would it be OK to use this pump?

- Thore

Hi, I look for a new pump for 2.0 HDI 2011 C5. The original pump code is 9673017080. Is this 9673173780 number pump is proper I do not now. Did you replace your pump? If you replace with which code?

[PaulC5]

The reply to the parts number request is on page 80 about half way down viewtopic.php?t=69962&start=1185

[fcesur77]

The reply to the parts number request is on page 80 about half way down viewtopic.php?t=69962&start=1185

Thanks but Marc did not mention about the same code steering pump. According to the RPO number of my car, proper steering pump code is 400828. However, I can not find 400828 code. There is only 4008E2. I am not sure whether both alternative to each other. The only information I need is the both pumps are equivalent to each other.