CALPAC INSTALLATION-ENGINE START/NO RUN INFORMATION

MODELS AFFECTED: 1984 CIMARRONS

After replacement of an ECM on any 1984 Cimarron, the technician may experience a condition where the engine will crank but will not run. This condition may result from the failure to transfer the Calpac from the original ECM to the replacement ECM.

The Calpac supplies valuable information to the ECM such as the number of cylinders in the engine, when to energize the injectors and, therefore, how to calculate the desired amount of fuel for the engine.

The Calpac is adjacent to the PROM and thus can be found by removing the PROM access cover. It is approximately half the size of a PROM and is installed within a socket in the same manner as a PROM (see Figure 1).

When diagnosis leads to replacing the ECM, the Calpac and PROM should both be transferred from the faulty ECM to the replacement ECM.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.