ENGINE GENERAL INFORMATION AND DIAGNOSIS (M13 ENGINE) 6-2-139
Troubleshooting
Step Action Yes No
1Was “Engine and Emission Control System
Check” performed?
Go to Step 2. Go to “Engine and Emis-
sion Control System
Check”.
2 Check MAP sensor and its circuit.
1) Connect scan tool to DLC with ignition
switch turned OFF.
2) Turn ignition switch ON.
3) Check intake manifold pressure.
Is it 146 kPa (43.1 in.Hg) or 0 kPa (0 in.Hg)?
Go to Step 3. Intermittent trouble.
Check for intermittent
referring to “Intermittent
and Poor Connection
Inspection” in Section 0A.
If OK, go to Step 9.
3 Check MAP sensor power supply voltage.
1) Disconnect connector from MAP sensor
with ignition switch tuned OFF.
2) Check for proper connection of MAP sensor
at “WHT/GRN”, “LT GRN/RED” and “BRN/
WHT” wire terminals.
3) Turn ON ignition switch, measure voltage
between engine ground and “WHT/GRN”
wire terminal. See Fig. 1.
Is voltage 4 – 5 V?
Go to Step 6. Go to Step 4.
4 Check MAP sensor power supply voltage.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Remove ECM from vehicle body and then
connect connectors to ECM.
3) Turn ON ignition switch, measure voltage
between vehicle body ground and “E22-8”
terminal.
Is voltage 4 – 5 V?
“WHT/GRN” wire in open
circuit.
Go to Step 5.
5 Check MAP sensor power supply circuit.
1) Disconnect connectors from TP sensor with
ignition switch turned OFF.
2) Turn ON ignition switch, measure voltage
between vehicle body ground and “E22-8”
terminal.
Is voltage 4 – 5 V?
Faulty TP sensor. “WHT/GRN” wire shorted
to ground or other circuit.
If wires are OK, substi-
tute a known-good ECM
and recheck.
6 Check MAP sensor ground circuit.
1) Measure resistance between “BRN/WHT”
wire terminal in MAP sensor harness con-
nector and engine ground.
Is resistance below 5
Ω
?
Go to Step 8. Go to Step 7.
7 Check ground circuit.
1) Disconnect connectors from ECM with igni-
tion switch turned OFF.
2) Remove ECM from vehicle body and con-
nect connectors to ECM.
3) Measure resistance between “E22-28” ter-
minal and vehicle body ground.
Is resistance below 5
Ω
?
“BRN/WHT” wire in open
or high resistance circuit.
ECM grounds “E23-1”
and/or “E23-2” circuit in
open or high resistance.
If wires are OK, substi-
tute a known-good ECM
and recheck.
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