3176B, C-10, C-12 & 3406E TRUCK ENGINES Caterpillar

The 3176B, C-10, C-12, & 3406E Truck Engine Electronic Control Module or ECM is the heart of the system. So when a problem occurs, it is easy to jump to the conclusion that the ECM is responsible. That is usually the wrong conclusion.

Most failures occur at the wiring and connectors or a sensor input/output. Follow the troubleshooting guide procedures, and do not replace an ECM on speculation!

However, when your troubleshooting indicates that a failure has, in fact, occurred in the ECM, the following procedure outlines the steps required to replace a faulty ECM.

ECM Replacement Procedure

1. Make sure the new ECM repairs the problem by first temporarily installing the new ECM. Do this by hanging it on the side of the engine. Transfer the Personality Module from the suspect ECM to the new one. Program any parameters necessary to check the ECM for the test. For example, Vehicle Speed Parameters need to be programmed to check the vehicle speed circuit. Program the parameters exactly the same as they were in the suspect ECM. Check out the new ECM. If it repairs the problem, reconnect the old ECM with its' Personality Module returned to it from the new ECM. Recheck the old ECM to make sure the problem stays with the ECM.

2. Record customer parameters from the failed ECM using the ET ECM Replacement feature under the Copy Configuration Menu or perform the following:

- Obtain and record the Customer Passwords. If the customer (owner) has lost or forgotten his passwords, refer to "Customer Passwords" on page 47.

- Use the ECAP or ET to access "Read Customer Specified Parameters" from the ECM being replaced.

- Use the "Customer Parameter Worksheet" on page 52, to record the customer parameters.

3. Record ECM lifetime Totals.

- Use the "Lifetime Totals Worksheet" on page 53, to record the old ECM Lifetime Totals.

4. Remove the Personality Module from the faulty ECM (if not using Flash Programming).

5. Replace the faulty ECM.

6. Install the Personality Module into the new ECM, or Flash Program the Personality Module. The new ECM is shipped with a blank Personality Module. If Flash Programming use the most recent Personality Module available.

7. Obtain Factory Passwords.

- Using the "Factory Passwords Worksheet" on page 51, record the following information from the engine information plate, Full Load Setting, Full Torque Setting, Engine Serial Number.

- Record the mileage from the vehicle odometer.

- Use the ECAP or ET to access "Read/Change System Configuration Parameters". When the Factory Specified Passwords screen appears, record the following information, ECM serial number, Engine serial number, ECAP or ET serial number, Total Tattletale, and Reason Code.

- Leave the ECAP or ET on the Factory Specified Passwords screen and obtain the Factory Passwords. Fill out the "Factory Passwords Worksheet" on page 51.

NOTE: Full Load Setting (FLS), Full Torque Setting (FTS) and engine serial number can be programmed without factory passwords on a new ECM. System Configuration parameters should be entered before the Customer Specified Parameters are entered. If Customer Parameters are entered before the System Configuration Parameters, the Total Tattletale will change. It will then be necessary to obtain another set of Factory Passwords to access "Read/Change System Configuration Parameters".

8. Use the ET ECM Replacement Feature to program the new ECM or perform the following:

NOTE: On initial power up of a new ECM, five (six for a 3406E) parameters must be programmed to avoid a 253-02 Check Customer Or System Parameters (56) code. These codes are Full Load Setting (FLS), Full Torque Setting (FTS), Vehicle Speed Calibration (ppm), Rating Number, Engine Serial Number, and Injector Codes (3406E only).

- Use the ECAP or ET to access "Read/Change System Configuration Parameters". Enter the Full Load Setting, Full Torque Setting, and Engine serial number recorded on the worksheet.

- Use the ECAP or ET to access "Read/Change Customer Specified Parameters". Enter the Customer Specified Parameters and the original Customer Passwords recorded on the worksheet.

- Use the ECAP or ET to access "Read/Change Current Totals" (it is under the Trip Data main menu). Record information using the "Factory Passwords Worksheet" to get the Factory Passwords. Enter the Totals recorded on the worksheet from the original ECM.

- Use the ECAP or ET to access "Calibrate Sensors", and calibrate the Boost Sensor (refer to procedure "PC-37: Boost Sensor Calibration" on page 293). Only for OCT94 or earlier Personality Modules.

- Use the ECAP or ET to access "Calibrate Sensors", and calibrate the Engine Speed/Timing Sensor (refer to procedure "PC-31: Engine Speed/Timing Circuit Test" on page 233).

- For the 3406E, use the ECAP or ET to access "Read/Change Injector Codes", and program the Injector Codes for each Injector.