DTC 1-3-2 No RPM Sensor Signal

Tachometer (RPM):

Conditions for DTC:
- No engine speed for at least 10 seconds with generator sending charging signal.

Sources of fault:
- Signal lead short-circuited to battery supply.
- Signal lead short-circuited to ground.
- Open-circuit in signal lead.
- Contact resistances too high.
- No charging signal from generator.
- Fault in engine management system.

Symptoms:
- Tachometer not working.
- Generator warning light (see 'Description and Operation') does not come on with ignition switch in position II.
- Intermittent fault.

Checking DTCs In Engine Management System:





- Turn ignition on.
- Check if DTC 1-3-1 is posted in engine management system, DLC A2.

If DTC 1-3-1 Is posted:
- Fault in engine management system. See appropriate ALLDATA powertrain management section.

If DTC 1-3-1 is not posted:
- Check signal lead to instrument panel, see below.

Checking Signal Lead To Instrument Panel:





- Ignition off.
- Expose instrument panel. (Remove Dash Board Cover) Service and Repair
- Undo instrument panel connector.
- Connect test box to cable harness connector and check ground points. Connecting Test (Breakout) Box

Test Box On Dashboard/Cable Harness Dashboard:

- Connect test box between instrument panel and cable harness connectors.
- Start engine.





- Connect a voltmeter across # 11 (# A11) and # 15 (# A15) on test box.
- Voltmeter should read approx. 6.5 V.

If reading is correct:
- Intermittent open-circuit in signal lead between instrument panel terminal # A11 and engine management system # B21 or ignition control system # B29, depending on type of engine management system.
- # B21: Fenix 5.2, Motronic 4.3
- # B29: LH 3.2, EZ-K.
- Check signal lead and connections for loose contacts and contact resistance. Checking Cables and Terminals

If voltmeter reads 0 V:
- Open-circuit or short-circuit to ground in signal lead between instrument panel terminal # A11 and engine management system terminal # B21 or ignition control system # B29, depending on type of engine management system.
- # B21: Fenix 5.2, Motronic 4.3
- # B29: LH 3.2, EZ-K.
- Check signal lead and connections for open-circuit and short-circuit to ground. Checking Cables and Terminals

If voltmeter reading equals battery voltage:
- Short-circuit to battery supply in signal lead between instrument panel terminal # A11 and engine management system terminal # B21 or ignition control unit # B29, depending on type of engine management system.
- # B21: Fenix 5.2, Motronic 4.3
- # B29: LH 3.2, EZ-K.
- Check signal lead and connections for short-circuit to battery supply. Checking Cables and Terminals

Checking Charge Signal From Generator:





- Ignition off.
- Expose instrument panel. (Remove Dash Board Cover) Service and Repair
- Undo instrument panel connector.
- Connect test box to cable harness connector and test ground points. Connecting Test (Breakout) Box

Test Box On Dashboard/Cable Harness Dashboard:

- Connect test box between instrument panel and cable harness connectors.
- Turn ignition on.





- Connect a voltmeter across # 13 (# A13) and # 15 (# A15) on test box.
- Voltmeter should read approx. 1.5 V.

If reading is correct:
- Intermittent open-circuit between instrument panel terminal # A13 and D+ on generator.
- Check lead and connections for intermittent open-circuit. Checking Cables and Terminals

If voltmeter reading equals battery voltage:
- Open-circuit between instrument panel terminal # A13 and D+ on generator.
- Check lead and connections for open-circuit. Checking Cables and Terminals

Checking Generator Leads and Connections:





- intermittent open-circuit or intermittent short-circuit to battery supply in lead between instrument panel terminal # A13 and generator terminal D+.
- Check lead and connections for intermittent open-circuit and intermittent short-circuit to battery supply. Checking Cables and Terminals