When a type A diagnostic fails, a DTC sets immediately and the Malfunction Indicator Lamp (MIL) illuminates. When a type B diagnostic fails, a DTC sets and the MIL illuminates if the fault is present after two consecutive drive trips. A type C DTC sets after two failures and stores in memory but does not illuminate the MIL. A type D DTC is not used during CNG operation.
DTC | Description | Type | Illuminate MIL |
|---|---|---|---|
12 | Diagnostic System Ready | N/A | N/A |
13 | Function Readiness | N/A | N/A |
14 | ECT Sensor Circuit High Voltage | B | Yes |
15 | ECT Sensor Circuit Low Voltage | B | Yes |
16 | ECT Excessive Time to Closed Loop | A | Yes |
21 | TP Sensor Circuit High | B | Yes |
22 | TP Sensor Circuit Low | B | Yes |
23 | IAT Sensor Circuit Low Voltage | B | Yes |
25 | IAT Sensor Circuit High Voltage | B | Yes |
26 | TP Sensor Performance | B | Yes |
27 | Quad Driver Output (1998 Only) | D | No |
32 | MAP Sensor Performance | B | Yes |
33 | MAP Sensor Circuit High | B | Yes |
34 | MAP Sensor Circuit Low | B | Yes |
35 | MAF System Performance | A | Yes |
36 | MAF Sensor Circuit Low Voltage | A | Yes |
37 | MAF Sensor Circuit High Voltage | A | Yes |
41 | CKP Sensor Circuit | A | Yes |
42 | HO2S Insufficient Activity Bank 1 Sensor 1 | B | Yes |
43 | HO2S Heater Circuit Bank 1 Sensor 1 (1997/1998) | A/B | Yes |
44 | HO2S Circuit Low Voltage Bank 1 Sensor 1 | B | Yes |
45 | HO2S Circuit High Voltage Bank 1 Sensor 1 | B | Yes |
51 | Gas Mass Sensor Circuit Low Frequency | A | Yes |
52 | Gas Mass Sensor Circuit High Frequency | A | Yes |
53 | Gas Mass Sensor Circuit Range Performance | A | Yes |
55 | Fuel Trim System Lean | B | Yes |
56 | Fuel Trim System Rich | B | Yes |
58 | AF ECU Failure | A | Yes |
62 | HO2S Heater Circuit Bank 2 Sensor 1 | B | Yes |
63 | HO2S Insufficient Activity Bank 2 Sensor 1 (1997/1998) | A/B | Yes |
64 | HO2S Circuit Low Bank 2 Sensor 1 | B | Yes |
65 | HO2S Circuit High Voltage Bank 2 Sensor 1 | B | Yes |
66 | Fuel Pressure Sensor Circuit High Voltage (1998 Only) | A | Yes |
67 | Fuel Pressure Sensor Circuit Low Voltage (1998 Only) | D | No |
