A/F Sensor (Sensor 1) Heater Circuit Malfunction - Honda 2002 Accord Manual

DTC P I 166: A/F Sensor (Sensor 1) Heater
Circuit Malfunction
1. Reset the ECM/PCM (see page 11-4).
2. Start the engine.
Is DTC P1166 indicated?
Y E S — Go to step 3.
NO — Intermittent failure, system is OK at this time.
Check for poor connections or loose wires at C102
(located under the under-hood fuse/relay box), A/F
Sensor relay, the A/F Sensor (Sensor 1) and the
ECM/PCM. •
3. Check the following fuses:
• POWER S E A T (20A) fuse in the under-hood
fuse/relay box.
• No. 4 E C U (ECM/PCM) CRUISE CONTROL (15A)
fuse in the driver's under-dash fuse/relay box.
• No. 6 LAF HEATER (20A) in the passenger's
under-dash fuse/relay box.
Are any of the fuses blown?
Y E S —Repair short in the wire between the A/F
Sensor relay and the fuses. •
N O - G o to step 4.
4. Measure voltage between ECM/PCM connector
terminals B19 and B20, 30 seconds after the
ignition switch is turned ON (II).
E C M / P C M CONNECTOR B (25P)
P02SHTC
(BLK/WHT)
1 2 3 4 5 7 8
9 10
11 12 13 14 16 17 18
19
20 21 22 23 24 25
LG1 (BRN/BLK)
Wire side of female terminals
Is there battery voltage?
Y E S - S u b s t i t u t e a known-good ECM/PCM and
recheck (see page 11-5). If the symptom/indication
goes away, replace the original ECM/PCM. •
N O - G o t o step 5.
5. Measure voltage between ECM/PCM connector
terminals C13 and B20.
E C M / P C M C O N N E C T O R S
B (25P)
1
2
3 4 5
/
7 8
9 10
11 12 13 14 / 16 17 18
19 20 21 22 2 ^ 24 25
L G 1 ( B R N / B L K )
C ( 3 1 P )
1 2 3
/
5 6 7 8 9 10
/ /
13 14 15 16 17 18 19 20 21
/
23
1%
25 26 27 28 29 30
/
P02SHTC+
(WHT)
W i r e s i d e o f f e m a l e t e r m i n a l s
Is there battery voltage?
Y E S - G o to step 6.
N O - G o t o step 10.
6. Turn the ignition switch OFF.
7. Disconnect ECM/PCM connector B (25P).
8. Turn the ignition switch ON (II).
9. Connect ECM/PCM connector terminal B16to body
ground with a jumper wire, then measure voltage
between ECM/PCM connector terminals B19 and
B20.
E C M / P C M CONNECTOR B (25P)
P02SHTC
(BLK/WHT)
1
2 3
4 5 7 8
9
10
11 12 13 14 16 17 18
19 20 21 22 23 24 25
LG1 (BRN/BLK)
W i r e side of female terminals
JUMPER
WIRE _
Is there battery voltage?
Y E S - S u b s t i t u t e a known-good ECM/PCM and
recheck (see page 11-5). If the symptom/indication
goes away, replace the original E C M / P C M . •
NO—Repair open or short in the wire between A/F
Sensor (Sensor 1) and ECM/PCM (B19).H
(cont'd)
11-81