Here is the TSB for it. It does not affect all Mazda 5s so check your VIN number. I have one of the earliest 06 models in the states, and my VIN # is below the range indicated. I have had no problems, and I have driven this thing everwhere including hot weather.
TSB: 06-002/09
2007-2009 MAZDA3 AND 2007-2009 MAZDA5 - HEAVY STEERING EFFORT WITH POWER STEERING MALFUNCTION INDICATOR LAMP ON AND DTC C1099
APPLICABLE MODEL(S)/VINS
2007-2009 Mazda3 vehicles (NOT including Mazdaspeed3) with VINs below (produced between April 1, 2007 and November 4, 2008)
2007-2008 JM1BK****** 742201 - 880507
2008-2009 JM1BK****** 100002 - 251982
2007-2009 Mazda5 vehicles with VINS JM1CR***** 155672 - 349055 (produced between produced between April 1, 2007 and November 4, 2008)
DESCRIPTION
Some customers may feel that the steering effort is hard or heavy with power steering malfunction indicator lamp illumination and DTC C1099 [ELECTRO HYDRAULIC POWER ASSIST STEERING (EHPAS)] stored in memory. This problem is caused by contamination of the system from such things as corrosion getting inside the power steering line, sticking in the power steering pump, and lowering the revolution speed. The system then goes into a fail safe function.
Customers having this concern should have their vehicle repaired using the following repair procedure.
REPAIR PROCEDURE OUTLINE
1. Verify customer concern.
2. Clean the steering gear box by flushing all fluid lines with 10 quarts of fluid.
3. Remove the electric power steering oil pump assembly (A) and pipe assembly (B).
4. Replace the power steering oil pump unit (shaded part of A) on the pump assembly with oil pump kit.
5. Install the repaired power steering oil pump assembly and new pipe assembly.
6. Fill the pump reservoir with ATF MIII and remove air from the line.
<snip>
PART(S) INFORMATION
Part Number
Description
Qty.
Note
BBM4-32-68Z
Oil Pump Service Kit
1
Kit consists of oil pump (B), bolts (C), joint (D), and O-ring (E).
BP4L-32-47YM
Pipe Assembly
1
9956-21-400
Gasket
4
0000-77-110E-01 or 0000-77-MERC-QT
ATF M-III
12
Up to 12 Quarts