Closed Throttle Position (CTP) Test, Adjustment

NOTE: This procedure is only possible using HHT.

Listing of Test Steps
1. HHT with multiplexer to data link connector
Connect/disconnect.
2. Throttle control
Check throttle operation and condition.
Lubricate bearings, gate levers and ball sockets.
2.1 WOT, CTP stop at pedal value sensor (B37)
Check.
3. Selector lever position
P/N
4. Engine oil temperature
Check.
5. ECT
Check.
6. Ignition timing
Engine: at Idle
Check. Test and Adjustment Data [Specifications]
7. Engine RPM at idle
Check. Test and Adjustment Data [Specifications]
8.0 On/off ratio
Check (Only possible using HHT)
8.1 CTP recognition (accelerator pedal not depressed)
Check, HHT display ON (Only possible using HHT)
9. Closed throttle under load
Check with selector lever in "D", with service and parking brake applied, and consumers on.


Connection Diagram - Measuring engine RPM without HHT

Connecter 1: Circuit 31 (ground)
Connecter 13: TN-Signal

CAUTION: Engine 120 - Set cylinder selection switch to 6 cylinder position.





X11/4 Data link connector, (DTC readout, 38-pole)
030 Engine analyzer with oscilloscope (RPM reading only)
075 Adapter