Chart C1 - ECM Replacement Check Chart
In order to reduce incidents of repeat ECM failure, a revised ECM diagnostic procedure is available. Beginning in 1982, most ECMs are equipped with Integrated Circuits (IC) in place of separate transistors to operate various controlled components.
These ICs, called Quad-Drivers (QDR), have 4 separate outputs, meaning that each QDR can operate up to 4 different components. An inoperative QDR can result in ECM output becoming open or shorted to ground. Often, all 4 outputs of a QDR will fail, even if just one QDR circuit is faulty.
Refer to the following tables to determine which ECMs contain QDRs. Since this procedure is not applicable to ECMs which do not contain QDRs, those ECMs are not listed.
Performing the diagnostic flow chart will identify an inoperative QDR. Once the circuit is identified, it must be repaired to eliminate repeat ECM failure. This diagnostic procedure must be used when "Replace ECM" is the conclusion of any procedure.
ECM QDR IDENTIFICATION
| Application |
Output Terminals |
| 1984-85 |
| 1226458, 1226460 |
| QDR No. 1 |
C1, C2, A2, A3 |
| QDR No. 2 |
A4, A5, A7, A7 |
ECM QDR IDENTIFICATION
| Application |
Output Terminals |
| 1983-84 |
| 1226153, 1226452, 12266454, 1226455. 1226519 |
| QDR No. 1 |
G, E, 6, 4 |
| QDR No. 2 |
8, 19, P, P |
| QDR No. 3 |
18, 18, T, T |
| 1985-87 |
| 226457, 1226519, 1226865, 1226866, 1227076, 1227169, 1227301, 1227855, 1228079 |
| QDR No. 1 |
G, E, 6, 4 |
| QDR No. 2 |
8, 19, P, P |
| QDR No. 3 |
18, 18, T, T |
ECM QDR IDENTIFICATION
| Application |
Output Terminals |
| 1984-85 |
| 1226461 |
| QDR No. 1 |
A2, A4, A4, A5 |
| QDR No. 2 |
A3, A3, D2, D2 |
| QDR No. 3 |
A7, A7, C2 |
| 1985-87 |
| 1226869, 1226870, 1226948, 1227065, 1227784 |
| QDR No. 1 |
A2, A4, A4, A5 |
| QDR No. 2 |
A3, A3, D2, D2 |
| QDR No. 3 |
C2, A7, A7 |
| 1986 |
| 1227151 |
| QDR No. 1 |
C1, C2, A2, A3 |
| QDR No. 2 |
A4, A5, A7, A7 |
| 1986-87 |
| 1227153, 1227170, 1227302 |
| QDR No. 1 |
A2, A4, A4, A5 |
| QDR No. 2 |
A3, A3, D2, D2 |
| QDR No. 3 |
A7, A7, C2 |
| 1227165 |
| QDR No. 1 |
A3, A7, C2, D12 |
| QDR No. 2 |
A2, A4, A5, C1 |
| 1985-87 |
| 1226459 |
| QDR No. 1 |
A3, A3, D3, D3 |
| QDR No. 2 |
A7, A7, D2 |
| QDR No. 3 |
A2, A4, A4, A5 |
| 1227730 |
| QDR No. 1 |
E7, E8, E9, F7 |
| QDR No. 2 |
F1, F2, F3, F4 |
| QDR No. 3 |
F5, F5, F6, F8 |
| 1986-87 |
| 1227057 |
| QDR No. 1 |
A3, A7, D2, D3 |
| QDR No. 2 |
A4, A5, B2, B9 |
| 1227148, 1227783, 1227886 |
| QDR No. 1 |
A3, A3, D3, D3 |
| QDR No. 2 |
A7, A7, A8, D2 |
| QDR No. 3 |
A2, A4, A4, A5 |
| 1987 |
| 1227750 |
| QDR No. 1 |
2A1, 2A8, 2A10, 2A11 |
| QDR No. 2 |
3C7, 3C8, 3C9, 3C10 |
| QDR No. 3 |
3D5, 3D5, 3D4, 3C6 |
| QDR No. 4 |
3C4, 3C4, 3C5, 3D4 |
ECM QDR IDENTIFICATION
| Application |
Output Terminals |
| 1983-87 |
| 1225610, 1226100, 1226026, 1226430 |
| QDR No. 1 |
Black 9, Black 14, Black 16, White 20 |
| QDR No. 2 |
Black 7, Black 22, White 19, White 19 |
| 1226026, 1226430 |
| QDR No. 1 |
Black 9, Black 14, Black 16, White 20 |
| QDR No. 2 |
Black 7, Black 22, White 19, White 19 |
| 1226156 |
| QDR No. 1 |
White 20, Black 7, Black 9 |
| 1226864 |
| QDR No. 1 |
Black 7, Black 9, White 20 |
| 1226867 |
| QDR No. 1 |
A2, A3, A4, C2 |
| QDR No. 2 |
C1, A5, A7, A7 |
| 1226868, 1227746, 1227747 |
| QDR No. 1 |
A2, A3, C1, C2 |
| QDR No. 2 |
A4, A5, A7, A7 |
| 1227137, 1227429 |
| QDR No. 1 |
A2, A3, C1, C2 |
| QDR No. 2 |
A4, A5, A7, A7 |
| 1227748 |
| QDR No. 1 |
Black 7, Black 7, Black 18, White 18 |
| QDR No. 2 |
Black 3, Black 4, White 21, White 22 |
| 1227749 |
| QDR No. 1 |
E7, E8, E9, F7 |
| QDR No. 2 |
F1, F2, F3, F4 |
ECM QDR IDENTIFICATION
| Application |
Output Terminals |
| 1983-86 |
| 1226028, 1226462, 1226930 |
| QDR No. 1 |
Blue 9, Blue 14, Blue 16, Red 20 |
| QDR No. 2 |
Blue 7, Blue 22, Red 19, Red 19 |
| 1986-87 |
| 1227056 |
| QDR No. 1 |
A7, A7, A11, A11 |
| QDR No. 2 |
A2, A5, C3, C3 |
| QDR No. 3 |
C1, D2, D3, D10 |
| QDR No. 4 |
A3, A3, A4, A4 |
Courtesy of GENERAL MOTORS CORP.