SES Light with Various 5 Volt Reference Sensor DTCs - Inspect Wiring - keywords damage ECM P0112 P0113 P0220 P0222 P0223 P0452 P0463 P0530 P1120 P1220 P1221 P1271 P1275 P1280 P1682 P2120 P2122 P2125

This PI has been revised to add additional diagnostic information. Please discard PIP3192.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

On rare occasions, a SES light may be encountered with any of the following DTCs: P0013, P0107, P0112, P0113, P0120, P0122, P0123, P0200 P0201, P0202, P0203, P0204, P0205, P0206, P0220, P0222, P0223, P0452, P0463, P0530, P0713, P1120, P1220, P1221, P1271, P1275, P1280, P1481, P1515, P1540, P1633, P1635, P1639, P1682, P2120, P2122, P2123, P2125, P2127, P2128

If the SI diagnostics do not isolate a cause for this concern due to the intermittent nature of the concern, the following information may be helpful:

1. Inspect the main engine wiring harness between the PCM and the Generator Assembly for a potential short to ground. There is a metal wiring harness retainer in this area that secures the main engine harness. If the harness conduit is mis-positioned, some of the wiring may become exposed and chaff on the harness retainer. This may eventually cause the exposed circuit to short to ground.
2. Inspect the 3 harnesses that connect to the PCM for potential shorts to ground on the metal PCM mounting bracket, just below the PCM. There are plastic harness retainers on the PCM bracket that secure the harnesses to the PCM bracket. If the harness conduit is mis-positioned, some of the wiring may become exposed and chaff on the PCM bracket. This may eventually cause the exposed circuit to short to ground.

If a chaffed circuit is found in either of the locations above, repair the circuit (s) using the necessary SI procedures. Once the circuit is repaired, tape the area of the affected area of the harness to prevent the wires from becoming exposed in the future and secure the harness using the original harness retainer.

3. If SI diagnostics continue to lead to PCM replacement even though it was recently replaced for the same concern, the PCM may have internal damage due to a shorted driver circuit or low reference circuit.

Since this PCM does not contain internal fault protection, internal PCM damage may occur if a high side driver circuit/component shorts to ground, or if a low side driver circuit/component or low reference circuit shorts to power.

If internal PCM damage is suspected, operate all PCM drivers with a Tech 2 to ensure proper operation. If a PCM driver exhibits abnormal operation, inspect the related driver circuit/component for a short and repair as necessary. If normal driver operation is noted, inspect all driver circuits/components for shorts, especially near the PCM as described in steps 1 and 2 above. If there is no problem found with any of the drivers or driver circuits but internal PCM damage is still suspected, determine if the PCM is setting high voltage DTCs for components in one of the groups below. If the PCM is setting high voltage DTCs for only 1 of the 3 groups, the internal PCM damage is most likely due to a component in this group having its low reference circuit shorted to power.

For example, if a P0113 (IAT Sensor High Voltage), P0530 (AC Pressure Sensor Circuit), P2123 (APP Sensor 1 High Voltage), and a P2128 (APP Sensor 2 High Voltage) continue to set with no other DTCs, one of the Group 1 components below most likely has a shorted low reference circuit. If there is no problem found with any of the external low reference circuits in Group 1, the fuel pump module should also be removed so the fuel level sensor low reference circuit can be inspected to ensure that it is not shorted inside of the fuel pump module.

GROUP 1

GROUP 2

GROUP 3

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.