3C
DTC 42
DTC Detecting Condition and Trouble Area
DTC detecting condition Trouble area
42: Engine Speed Malfunction
Engine revolution signal is not input for specified time at driving.
• Engine revolution signal circuit
• ECM
• Other ECU that inputs Engine revolution signal
• 4WD control module
Wiring Diagram
[A]: 4WD control module connector (View: [a]) [D]: ECM terminal (M13A engine without VVT model) 2. To other ECU
[B]: ECM connector (View: [a]) (M13A engine without VVT model) [E]: ECM terminal (M13A engine with VVT model) 3. 4WD control module
[C]: ECM connector (View: [a]) (M13A engine with VVT model) 1. ECM 4. CPU
DTC Confirmation Procedure
1) Drive vehicle at 30 km/h (19 mile/h) or more for 5 minutes.
DTC Troubleshooting
Step Action YES NO
1
ECM DTC check
1) Check DTC of ECM.
M13A engine without VVT model: icon 
M13A engine with VVT model: icon 
K9K engine model: icon 
Is there any DTC(s) detected?
Go to troubleshooting for applicable DTC.
Go to Step 2.
2
Engine revolution signal circuit check
1) Disconnect 4WD control module connector and ECM connector with ignition switch OFF.
2) Check engine revolution signal circuit (“BRN” wire) for open, short to ground and short to power circuit.
Is it in good condition?
Go to Step 4.
Go to Step 3.
3
Engine revolution signal circuit check
1) Disconnect connector of other ECU that inputs engine revolution signal with ignition switch OFF.
2) Check engine revolution signal circuit (“BRN” wire) for open, short to ground and short to power circuit.
Is it in good condition?
Substitute a known-good other ECU that inputs engine revolution signal and recheck.
Repair or replace engine revolution signal circuit.
4
Engine revolution pulse signal check
1) Connect ECM connector with ignition switch OFF.
2) Check engine revolution pulse signal
M13A engine without VVT model: icon 
M13A engine with VVT model: icon 
Is it in good condition?
Substitute a known-good 4WD control module and recheck.
Substitute a known-good ECM and recheck.