Mazda Protege 5. Manual - part 56
ON-BOARD DIAGNOSTIC [ENGINE CONTROL SYSTEM (FS)]
01–02B–44
Diagnostic procedure
POSSIBLE
CAUSE
•
TP sensor malfunction
•
MAF sensor malfunction
•
Electrical corrosion in TP signal circuit
•
Voltage drops in reference voltage (vref) supply circuit
•
Voltage drops in ground circuit
•
PCM malfunction
DTC P0121
TP circuit range/performance problem
STEP
INSPECTION
ACTION
1
VERIFY FREEZE FRAME DATA HAS BEEN
RECORDED
•
Has FREEZE FRAME DATA been recorded?
Yes Go to next step.
No
Record FREEZE FRAME DATA on repair order, then go to
next step.
2
VERIFY RELATED PENDING CODE OR
STORED DTC
•
Turn ignition key to ON (Engine OFF).
•
Retrieve pending or stored DTCs using WDS
or equivalent.
•
Is DTC P0101 also retrieved?
Yes Go to DTC P0101 troubleshooting procedure.
No
Go to next step.
3
VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
•
Check for related Service Bulletins availability.
•
Is any related repair information available?
Yes Perform repair or diagnosis according to available repair
information.
•
If vehicle is not repaired, go to next step.
No
Go to next step.
4
VERIFY CURRENT INPUT SIGNAL STATUS - IS
CONCERN INTERMITTENT OR CONSTANT
•
Start the engine.
•
Access ECT, TP and MAF PIDs using WDS or
equivalent.
•
Warm up the engine until ECT PID is above 70
°°°°
C {158
°°°°
F}.
•
Drive the vehicle.
•
Read TP PID while MAF PID is above 73.4 g/s
{9.7 lb/min}.
•
Is TP PID reading above 12.5%?
Yes Go to next step.
No
Intermittent concern exists. Go to INTERMITTENT
CONCERN TROUBLESHOOTING procedure.
(See 01–03B–4 INTERMITTENT CONCERN
TROUBLESHOOTING [FS].)
5
VERIFY TP PID
•
Clear DTC from PCM memory using WDS or
equivalent.
•
Start engine.
•
Access TP, MAF and RPM PIDs using WDS or
equivalent.
•
Read TP PID while MAF PID is below 4.8g/s
{0.6 Ib/min} and RPM PID is above 500 rpm.
•
Is TP PID reading above 50%?
Yes Go to Step 7.
No
Go to next step.
6
VERIFY CURRENT INPUT SIGNAL STATUS - IS
CONCERN INTERMITTENT OR CONSTANT
•
Drive the vehicle and read MAF PID.
•
Does MAF PID change in compliance with
driving condition?
Yes Intermittent concern exists. Go to INTERMITTENT
CONCERN TROUBLESHOOTING procedure.
(See 01–03B–4 INTERMITTENT CONCERN
TROUBLESHOOTING [FS].)
No
Check MAF sensor and related circuits and terminals.
(See 01–40B–28 MASS AIR FLOW (MAF) SENSOR
INSPECTION [FS].)
Repair or replace as necessary, then go to Step 11.
7
CHECK TP SENSOR TERMINALS FOR
ELECTRICAL CORROSION
•
Turn ignition key to OFF.
•
Disconnect TP sensor connector.
•
Check for electrical corrosion on male and
female TP sensor terminals.
•
Is any electrical corrosion found?
Yes Repair or replace suspected terminal or TP sensor, then go
to Step 11.
No
Go to next step.
8
CHECK GROUND CIRCUIT FOR VOLTAGE
DROP
•
Check resistance between TP sensor terminal
B (harness-side) and body ground.
•
Does resistance read approx. 0 ohm?
Yes Go to next step.
No
Repair or replace rusted or corroded PCM terminal 91
(harness-side).
Disconnect breakout box and go to Step 11.
9
VERIFY TP SENSOR
•
Does TP sensor resistance smoothly change
while gradually opening throttle valve?
Yes Go to next step.
No
Replace TP sensor, then go to Step 11.
1712-1U-01G(01-02B).fm 44 ページ ２００１年６月２９日 金曜日 午後３時２４分