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Acura RL (1996-2004 year). Manual - part 275

Idle Control System

Idle Air Control (IAC) Valve

The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0511: A problem in the Idle Air Control (IAC)

valve circuit.

— The MIL has been reported on.
— DTCP0511 is stored.

Problem verification:

1. Do the PCM Reset Procedure.

2. Start the engine.

Is DTC P0511 indicated?

YES

Check for an open in the wire

(IGP1 line):
1. Turn the ignition switch OFF.
2. Disconnect the IAC valve con-

nector.

3. Turn the ignition switch ON (II).
4. Measure voltage between body

ground and the IAC valve con-
nector terminal No. 2.

Is there battery voltage?

YES

Check the IAC valve function:
Momentarily connect PCM con-
nector terminals A5 and A12 with
a jumper wire several times.

Does the IAC valve click?

YES

Substitute a known-good PCM
and recheck. If symptom/indica-

tion goes away, replace the origi-

nal PCM.

Intermittent failure, system is OK
at this time. Check for poor con-
nections or loose terminals at
C253, (located at right shock
tower), C129 (IAC valve) and
PCM.

Repair open in the wire between
IAC valve and PGM-FI main relay.

Wire side of female terminals

Repair open or short in the wire
between PCM (AS) and IAC valve.

Replace the IAC valve.

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Brake Pedal Position Switch Signal

This signals the PCM when the brake pedal is depressed.

Are the brake lights on without
depressing the brake pedal?

Inspect the brake pedal position
switch (see

section 19)

Depress the brake pedal.

Do the brake lights come on?

YES

Is the fuse OK?

Check for an open in the wire
(BKSW line):

1. Depress the brake pedal.

2. Measure voltage between PCM

connector terminals E2 and
A26 with the brake pedal de-
pressed.

— Repair short in the wire be-

tween the brake pedal posi-
tion switch and the STOP

HORN (20 A) fuse.

— Replace the STOP HORN (20 A)

fuse.

Is there battery voltage?

Repair open in the wire between

the PCM (E2) and the brake pedal
position switch.

Brake pedal position switch sig-
nal is OK.

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Emission Control System

Exhaust Gas Recirculation (EGR) System (cont'd)

The HDS or the scan tool indicates Diagnostic Trouble Code (DTC) P0404: An insufficient lift of the Exhaust Gas

Recirculation (EGR) valve.

Is DTC P0404 indicated?

YES

Check for vacuum to the EGR
valve:

1. Disconnect the No. 11 hose from

the EGR valve.

2. Connect vacuum pump/gauge

to the hose.

3. Start the engine and let it idle.

Intermittent failure, system is OK
at this time. Check for poor con-
nections or loose terminals at
C251, C254 (located at right shock
tower), C107 (EGR valve) and
PCM.

Is there any vacuum?

VACUUM PUMP/GAUGE, 0-30 in.Hg

A973X - 041 - XXXXX

YES

No. 11 VACUUM
HOSE

Check for a malfunction in the
EGR valve vacuum control
solenoid valve:

1. Disconnect the control box 4P

connector.

2. Recheck the No. 11 hose for

vacuum.

(To page

(To page

(cont'd)

11-85

— The MIL has been reported on.
— DTC P0404 is stored.

Problem verification:
1. Do the PCM Reset Procedure.
2. Connect the SCS service con-

nector.

3. Start the engine. Hold the

engine at 3,000 rpm with no
load (in Park or neutral) until
the radiator fan comes on.

4. Drive the vehicle on the road for

about 10 minutes. Try to keep
the engine speed in the 1,700 -
2,500 rpm range.

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Emission Control System

Exhaust Gas Recirculation (EGR) System (cont'd)

(From page

11-85

)

Is there any vacuum?

Check for a short in the wire (ES
line):

1. Turn the ignition switch OFF.

2. Disconnect the PCM connec-

tor A (26P).

3. Check for continuity between

body ground and the control
box 4P connector terminal No. 2.

Is there continuity?

Substitute a known-good PCM
and recheck. If symptom/indica-
tion goes away, replace the origi-
nal PCM.

(From page

11-85

)

Check for a malfunction in the
EGR valve:

1. Move the vacuum pump/gauge

to the EGR valve.

2. With the engine at idle, apply

26.7 kPa (200 mmHg, 8.0 in.Hg)
of vacuum to the EGR valve.

Does the engine stall or run
rough and does the EGR valve
hold vacuum?

YES

Check for an open in the wire
(VCC2 line):

1. Turn the ignition switch OFF.
2. Disconnect the EGR v a l v e

position sensor 3P connector.

3. Turn the ignition switch ON (II).
4. Measure voltage between the

EGR valve position sensor 3P
connector terminals No. 1 and
No. 3.

Is there about 5 V?

(To page

11-87

)

Check vacuum hose routing of
the entire EGR system. If hose
routing is OK, replace the EGR
valve vacuum control solenoid
valve.

CONTROL BOX 4P CONNECTOR (C257)

Wire side of female terminals

Repair short in the wire between
PCM (A6) and EGR valve vacuum

control solenoid valve.

VACUUM
PUMP/GAUGE,
O - 30 in.Hg

A973X - 041 -
XXXXX

Replace the EGR valve.

EGR
VALVE

No. 11
VACUUM
HOSE

EGR VALVE POSITION SENSOR CONNECTOR (C107)

YES

(To page

11-87

)

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