C1122

DTC C1122: Engine Speed Signal

Wiring Diagram










DTC Detecting Condition and Trouble Area






DTC Troubleshooting



1.
Was "EPS System Check" performed?
YES
Go to Step 2.
NO
Go to EPS System Check:Electric Type.

2. DTC check

Check ECM for DTC referring to DTC Check DTC Check.

Is there any DTC(s) detected?
YES
Go to applicable DTC troubleshooting.
NO
Go to Step 3.

3. Engine speed signal circuit check

With ignition switch turned OFF, disconnect P/S control module connector.
Check P/S control module connector for proper connection.
If OK, turn ON ignition switch, measure voltage between "E11-12" wire terminal of P/S control module connector and vehicle body ground.

Is voltage 10 - 14 V?
YES
Go to Step 4.
NO
Go to Step 5.

4. ECM voltage check

With ignition switch turned OFF, connect P/S control module and ECM connectors.
Check engine speed signal output referring to Pinout Values and Diagnostic Parameters Inspection of ECM and Its Circuits.

Is it in good condition?
YES
Substitute a known-good P/S control module and recheck.
NO
Substitute a known good ECM and recheck.

5. Engine speed signal circuit check

Disconnect ECM connector.
Check that engine speed signal circuit is as follows.
- Insulation resistance of wire harness is infinity between "Engine speed signal circuit" terminal and other terminal at P/S control module connector.
- Wiring harness resistance of "Engine speed signal circuit" is less than 1ohms.
- Insulation resistance between "Engine speed signal circuit" and vehicle body ground is infinity
- Circuit voltage between "Engine speed signal circuit" and ground circuit is 0 - 1 V with ignition switch turned ON.

Is it in good condition?
YES
Substitute a known good ECM and recheck.
NO
Repair or replace defective circuit.