Usage:
Certain 3406B (PEEC) Truck Engines are now equipped with Power Demand Cruise Control (PDCC). These engines will operate similarly to standard PEEC engines, with some additional features. An understanding of these features is necessary to accurately service these engines.
PDCC is the first commercially-available use of the customized power control capability of PEEC. PDCC is available from Navistar in the 9300, 9600, and 9700 chassis with the following drivetrain: the 3406B (PEEC) Truck Engine rated at 310 hp at 1800 rpm (equipped with a specific personality module, either new 7X6350 or Remanufactured OR5994), a Dana-Spicer 1372B seven-speed transmission, and an International X400 rear axle with a 3.06 ratio. This is the only drivetrain compatible with PDCC.
PDCC is active only when the cruise control is engaged and the transmission is in gears five through seven. With PDCC inactive, the engines operates as a normal 310 hp PEEC engine. With PDCC active, the engine can deliver the torque of a 350 hp rating. This feature gives the fuel economy of a 310 hp engine on flat terrain while providing the hill-flattening torque of a 350 hp engine in rolling terrain. In addition, the lug curve is modified in seventh gear to discourage operation in deep lug.
Since PDCC is a new concept, a number of interesting driver complaints may occur. For example:
..."The engine operates fine in seventh gear, but after I downshift the power just isn't there."
Solution: Ask the driver if he activated the resume switch after downshifting. PDCC is active only while operating in cruise control. Also, if the complaint occurs while operation in cruise control, connect your ECAP (Electronic Control Analyzer Programmer) and operate the truck under the described conditions. While under lug and in the cruise mode, compare desired rack to actual rack and record results. Now flip the cruise on/off switch to the off position and repeat the test. The value for desired rack should be greater while operating in cruise control.
..."Power drops off in seventh gear sooner than in other gears."
Solution: This is normal. Operation of the engine in deep lug while in seventh gear is discouraged.
..."The engine operates fine until I downshift below fifth gear. The engine has less power in gears one through four. I activate the resume switch after each shift, but it doesn't seem to make any difference."
Solution: This is normal. PDCC is not active in gears one through four.
Troubleshooting of other PEEC situations should by done in accordance with the 3406B (PEEC) Programmable Electronic Engine Controls Test Procedures, Form SENR3479-02.
PAR (Performance Analysis Report) chassis dynamometer testing should be done in accordance with procedures in PAR Gram, Form LEXT8525, "PAR Testing 3176 and 3406B Truck Engines with Electronic Engine Controls" and OT8465 Performance Specification. This test will verify conformance of fuel rate and boost specifications to the base rating.