2006 ACURA CSX automatic transmission

SymptomProbable cause(s) Notes
14-26Automatic Transmission
Symptom Troubleshooting Index (cont’d)



Speedometer and
odometer do not
work
Output shaft (countershaft) speed
sensor defective
Check for a stored DTC, and check for loose
connectors.
Inspect the transmission range switch operation.
Check the output shaft (countershaft) speed
sensor installation.
Engine does not
revtohighrpm,
and the
transmission
upshifts at low rpm
(engine at normal
operating
temperature) VTEC rocker arms defective Check the engine rocker arms.
08/08/21 14:37:11 61SNR030_140_0028
ProCarManuals.com
DYNOMITE -2009-

(#'

)
General Operation
Torque Converter, Gears, and Clutches
Electronic Control
Hydraulic Control
Shift Control Mechanism
Lock-up Mechanism
14-28Automatic Transmission
System Description
The automatic transmission is a combination of a three-element torque converter and triple-shaft electronically
controlled unit which provides five speeds forward and one in reverse. The entire unit is positioned in line with the
engine.
The torque converter consists of a pump, turbine, and stator assembly in a single unit. The converter housing (pump)
is connected to the engine crankshaft and turns as the engine turns. Around the outside of the torque converter is a
ring gear which meshes with the starter drive gear when the engine is being started. The entire torque converter
assembly serves as a flywheel while transmitting power to the transmission mainshaft. The transmission has three
parallel shafts; the mainshaft, the countershaft, and the secondary shaft. The mainshaft is in line with the engine
crankshaft, and includes the 4th and 5th clutches, and gears for 5th, 4th, reverse, and idler. The mainshaft reverse gear
is integral with the mainshaft 4th gear. The countershaft includes the gears for 1st, 2nd, 3rd, 4th, 5th, reverse, park,
and the final drive. The final drive gear is integral with the countershaft. The countershaft 4th gear and the
countershaft r
everse gear can be locked to the countershaft providing 4th or r everse gear, depending on which way
the selector is moved. The secondary shaft includes the 1st, 2nd, and 3rd clutches, and gears for 1st, 2nd, 3rd, and
idler. The idler gear shaft is located between the mainshaft and the secondary shaft, and the idler gear transmits
power between the mainshaft and the secondary shaft. The gears on the mainshaft and the secondary shaft are in
constant mesh with those on the countershaft. When certain combinations of gears in the transmission are engaged
by the clutches, power is transmitted through the mainshaft, then to the secondary shaft to the countershaft, or
through the mainshaft to the countershaft to provide drive.
The electronic control system consists of the powertrain control module (PCM), sensors, and shift solenoid valves.
Shifting and lock-up are electronically controlled for comfortable driving under all conditions. The PCM is located in
the engine compartment.
The valve bodies include the main valve body, the regulator valve body, and the servo body. They are bolted to the
torque converter housing. The main valve body contains the manual valve, shift valves A, B, C, and E, the relief valve,
the lock-up control valve, the cooler check valve, the servo control valve, and the ATF pump gears. The regulator valve
body contains the regulator valve, the torque converter check valve, the lock-up shift valve, and the 1st and 3rd
accumulators. The servo body contains the servo valve, shift valve D, the accumulators for 2nd, 4th, and 5th, and shift
solenoid valves A, B, C, D, and E. Fluid from the regulator passes through the manual valve to the various control
valves. The 1st, 3rd, and 5th clutches receive fluid from their respective feed pipes, and the 2nd and 4th clutches
receive fluid from the internal hydraulic circuit.
To shift gears, the PCM controls shift solenoid valves A, B, C, D, and E, and A/T clutch pressure control solenoid valves
A, B, and C, while receiving input signals from various sensors and switches located throughout the vehicle. The shift
solenoid valves shift the positions of the shift valves to switch the port leading hydraulic pressure to the clutch. A/T
clutch pressure control solenoid valves A, B, and C regulate their respective pressure, and pressurize the clutches to
engage them and their corresponding gears. The pressure of the A/T clutch pressure control solenoid valves also
applies to the shift valves to switch the port.
The lock-up mechanism operates in D (2nd, 3rd, 4th, and 5th gears). The pressurized fluid is drained from the back of
the torque converter through a fluid passage, causing the torque converter clutch piston to be held against the torque
converter cover. As this takes place, the mainshaft rotates at the same speed as the engine crankshaft. Together with
the hydraulic control, the PCM optimizes the timing and volume of the lock-up mechanism. When shift solenoid valve
E is turned on by the PCM, shift solenoid valve E pressure switches the lock-up shift valve on and off. A/T clutch
pressure control solenoid valve A and the lock-up control valve control the degree of lock-up.
08/08/21 14:37:16 61SNR030_140_0030
ProCarManuals.com
DYNOMITE -2009-

Gear SelectionPosition Description
Automatic Transmission Gear Position Indicator
Shift Indicator and M Indicator
14-29
The shift lever has five positions; P: PARK, R: REVERSE, N: NEUTRAL, D: DRIVE 1st thr ough 5th gear ranges with
D-position automatic shift mode and D-paddle shift mode, S: DRIVE 1st through 5th gear ranges with S-position
automatic shift mode and sequential sportshift mode.
P: PARK Front wheels locked; the park pawl engaged with the park gear on the countershaft. All clutches are released.
R: REVERSE Reverse; the reverse selector engaged with the c ountershaft reverse gear
and the 5th clutch engaged.
N: NEUTRAL All clutches are released.
D: DRIVE
(1st through 5th) General driving; starts off in 1st, shifts automatically to 2nd, 3rd, 4th, then
5th gear, depending on the vehicle speed and throttle position. Downshifts
through 4th, 3rd, 2nd, and 1st on deceleration to stop. The lock-up
mechanism operates in 2nd, 3rd, 4th, and 5th gears.
S: DRIVE
(1st through 5th) S-position
automatic shift
modeFor rapid acceleration at highway speeds and general driving; starts off in
1st, shifts automatically to 2nd, 3rd, 4th, then 5th gear, depending on
vehicle speed and throttle position. Downshifts through 4th, 3rd, 2nd, and
1st gear on deceleration to stop. The lock-up mechanism operates in 2nd,
3rd, 4th, and 5th gears.
Sequential
sportshift mode Manual gear shift driving; vehicle can starts off in 1st and 2nd gears, and
does not upshift automatically.
NOTE: D-paddle shift mode has been added for ’08-09 models.
Starting the engine is possible only in P and N because of a slide-type neutral-safety switch.
The A/T gear position indicator in the gauge control module (tach) shows which shift l ever position has been selected
without having to look down at the console.
When the transmission is switched into the sequential sportshift mode, the shift indicator in the gauge control module
(tach) displays the gear selected, and the M indicator next to the shift indicator comes on. The shift indicator also
displays the gear selected in the D-paddle shift mode, but the M indicator does not come on.
NOTE: D-paddle shift mode has been added for ’08-09 models.
08/08/21 14:38:16 61SNR030_140_0031
ProCarManuals.com
DYNOMITE -2009-

Î
(#'

)
Clutches and Gears
14-30Automatic Transmission
System Description (cont’d)
REVERSE
IDLER GEAR
5TH CLUTCH
3RD
CLUTCH MAINSHAFT
5TH GEAR
COUNTERSHAFT
REVERSE GEAR
REVERSE SELECTOR
HUB
REVERSE
SELECTORCOUNTERSHAFT
4TH GEAR COUNTERSHAFT
2ND GEAR
2ND CLUTCH
SECONDARY SHAFT
1ST GEAR
SECONDARY SHAFT
IDLER GEAR
FINAL DRIVEN GEARTORQUE CONVERTER
FINAL
DRIVE GEAR
1ST
CLUTCH
PARK GEAR
SECONDARY
SHAFT
2ND GEAR
DIFFERENTIAL ASSEMBLY RING GEAR
MAINSHAFT
REVERSE GEAR
IDLER SHAFT
IDLER GEAR SECONDARY SHAFT
3RD GEARCOUNTERSHAFT 3RD GEAR
COUNTERSHAFT
1ST GEAR
MAINSHAFT
IDLER GEAR
MAINSHAFT
4TH GEAR
4TH CLUTCH
COUNTERSHAFT
5TH GEAR
The five-speed automatic transmission uses hydraulically-actuated clutches to engage or disengage the transmission
gears. When hydraulic pressure is introduced into the clutch drum, the clutch piston moves. This presses the friction
discs and the steel plates together, locking them so they do not slip. Power is then transmitted through the engaged
clutch pack to its hub-mounted gear. Likewise, when the hydraulic pressure is bled from the clutch pack, the piston
releases the friction discs and the steel plates, and they are free to slide past each other. This allows the gear to spin
independently on its shaft, transmitting no power.
08/08/21 14:38:17 61SNR030_140_0032
ProCarManuals.com
DYNOMITE -2009-

Î(#'

)
Power Flow
P Position
N Position
14-32Automatic Transmission
System Description (cont’d)
TORQUE
CONVERTER
COUNTERSHAFT
MAINSHAFT
MAINSHAFT
IDLER GEAR
SECONDARY SHAFT
IDLER GEAR
IDLER SHAFT
IDLER GEAR IDLER SHAFT
SECONDARY SHAFT
COUNTERSHAFT
4TH GEAR
COUNTERSHAFT
REVERSE GEAR PARK GEAR
REVERSE
SELECTOR HUB
REVERSE
SELECTOR
Hydraulic pressure is not applied to the clutches. Power is not transmitted to the countershaft. The countershaft is
locked by the park pawl interlocking the park gear.
Engine power transmitted from the torque converter drives the mainshaft idler gear, the idler shaft idler gear, and the
secondary shaft idler gear, but hydraulic pressure is not applied to the clutches. Power is not transmitted to the
countershaft.
In this position, the position of the reverse selector differs according to whether the shift lever shifted from D or R: When shifted from D, the reverse selector engages with the c ountershaft 4th gear and the reverse selector hub, and
4th gear engages with the countershaft.
 When shifted from R, the reverse selector engages with the countershaft r everse gear and the reverse selectorhub,
and reverse gear engages with the countershaft.
08/08/21 14:38:17 61SNR030_140_0034
ProCarManuals.com
DYNOMITE -2009-

Î
Power Flow (cont’d)
In 2nd Gear
14-34Automatic Transmission
System Description (cont’d)
2ND CLUTCH
COUNTERSHAFT
2ND GEAR
SECONDARY SHAFT
2ND GEAR FINAL DRIVEN GEARTORQUE
CONVERTER
COUNTERSHAFT FINAL
DRIVE GEAR
MAINSHAFT
MAINSHAFT
IDLER GEAR
SECONDARY SHAFT
IDLER GEAR
IDLER SHAFT
IDLER GEAR IDLER SHAFT
SECONDARY SHAFT
 Hydraulic pressure is applied to the 2nd clutch, then the 2nd clutch engages the secondary shaft 2nd gear with thesecondary shaft.
 The mainshaft idler gear drives the secondary shaft via the idler shaft idler gear and the secondary shaft idler gear.
 The secondary shaft 2nd gear drives the countershaft 2nd gear and the countershaft.
 Power is transmitted to the final drive gear, which in turn drives the final driven gear.
08/08/21 14:38:18 61SNR030_140_0036
ProCarManuals.com
DYNOMITE -2009-


Power Flow (cont’d)
In 4th Gear
14-36Automatic Transmission
System Description (cont’d)
COUNTERSHAFT
4TH GEAR
4TH CLUTCH
MAINSHAFT
4TH GEAR
REVERSE SELECTOR
REVERSE SELECTOR HUB
FINAL DRIVEN GEARTORQUE
CONVERTER
COUNTERSHAFT FINAL
DRIVE GEAR
MAINSHAFT
 Hydraulic pressure is applied to the servo valve to engage the reverse selector with the c
ountershaft 4th gear and
the reverse selector hub while the shift lever is in forward range (D and S).
 Hydraulic pressure is also applied to the 4th clutch, then the 4th clutch engages the mainshaft 4th gear with the mainshaft.
 The mainshaft 4th gear drives the countershaft 4th gear and the countershaft.
 Power is transmitted to the final drive gear, which in turn drives the final driven gear.
08/08/21 14:38:19 61SNR030_140_0038
ProCarManuals.com
DYNOMITE -2009-


Power Flow (cont’d)
R Position
14-38Automatic Transmission
System Description (cont’d)
MAINSHAFT
REVERSE GEAR
REVERSE IDLER GEAR
COUNTERSHAFT
REVERSE GEAR4TH CLUTCH
REVERSE SELECTOR
REVERSE SELECTOR HUB
FINAL DRIVEN GEARTORQUE
CONVERTER
COUNTERSHAFT FINAL
DRIVE GEAR
MAINSHAFT
 Hydraulic pressure is applied to the servo valve to engage the reverse selector with the c
ountershaft reverse gear
and the reverse selector hub while the shift lever is in R.
 Hydraulic pressure is also applied to the 4th clutch, then the 4th clutch engages the mainshaft reverse gear with the mainshaft.
 The mainshaft reverse gear drives the c ountershaft reverse gear via the reverse idler gear.
 The rotational direction of the countershaft reverse gear is changed by the r everse idler gear.
 The countershaft r everse gear drives the countershaft via the reverse selector, which drives the reverse selector hub.
 Power is transmitted to the final drive gear, which in turn drives the final driven gear.
08/08/21 14:38:20 61SNR030_140_0040
ProCarManuals.com
DYNOMITE -2009-